HEBI Robotics | Documentation

Hardware

This section contains information specific to different hardware products and accessories. This includes information on modules and actuators, mechanical and electical accessories, robot kits, and details of any hardware-specific parameters for the APIs.

CAD files of the actuators and accessories are available at cad.hebi.us.

Modules

HEBI modules are ethernet-enabled devices that serve as building blocks for a robot or automated system. These modules include actuators to provide physical motion, and devices to interface with other sensors and I/O. Modules run firmware that allow them to communicate over a standard ethernet connection. Aspects of the firmware that are common to all modules are documented in Core Concepts, while aspects that are module-specific are documented below.

X-Series Actuators

The X-Series Actuators are 'smart' series-elastic actuators that integrate a brushless motor, geartrain, spring, encoders, and control electronics into a compact package that run on standard DC voltages and communicate using standard 10/100Mbps Ethernet. These actuators are designed to function as full-featured robotic components and enable the simultaneous control of position, velocity, and torque. Each actuator also has a wide range of other sensors, all of which can be easily accessed in the the various APIs.

Maximum Performance Range

The chart below indicates, separately, the maximum no-load speed and stall torque capabilities of the different models of X-Series actuators.

For example, an X8-9 is not capable of continuously providing 9 Nm of torque at 30 RPM. It is capable of a continously spinning at maximum speed of 30 RPM at a lower torque, and it is capable of exerting 9 Nm of torque at a lower speed.

More detailed performance information for each actuator is provided in the additional sections below.

Speed-Torque Curves

Each actuator has a range where it can perform continuously, as well as a peak range where it can perform intermittently. While X-Series actuators are rated running at 24V, they are capable of increased intermittent output at higher voltages.

The speed-torque curves below show both the continuous and intermittent operating ranges at 24V, as well as 36V and above. While the actuators can be run at bus voltages up to 48V, the performance is limited in firmware to the equivalent to 36V, allowing safe operation while decreasing the amount of current drawn at the power bus. The ranges shown below are approximate and assume an actuator in normal room-temperature conditions without additional cooling.

Frequency Response (Bode Plots)

Because the X-Series actuators are mechanically compliant, there is a limit to how rapidly they can react and track to desired commands. Overall, the actuators are designed to be able to replicate human-like motion, but the details of their frequency response depends on the model of the actuator and the details of its commanded action.

The plots below were generated with a mechanically fixed output and tracking a sinusoidal commanded effort of different amplitudes. The ranges shown below are approximate and assume an actuator running at 24V in normal room-temperature conditions without additional cooling. The gains that are used when controlling an actuator greatly effects the frequency response. The plots below use an effort Kp approximately 2X the default value that ships with a new actuator.

Mechanical Information

Actuator Model	Gear Ratio	Spring Stiffness	Output Bearing Capacity
X5-1	272.222 : 1	~70 Nm / rad	Radial / Axial Load Rating: 2.4 kN / 1.2 kN Cross-Moment Load Rating: 20 Nm
X5-4	762.222 : 1	~70 Nm / rad	Radial Load Rating Static: 2.2 kN Dynamic: 3.0 kN Axial Load Rating Static: 5.1 kN Dynamic: 6.9 kN Cross-Moment Load Rating Static: 55.6 Nm Dynamic: 75.5 Nm
X5-9	1742.222 : 1	~130 Nm / rad
X8-3	272.222 : 1	~70 Nm / rad
X8-9	762.222 : 1	~70 Nm / rad
X8-16	1462.222 : 1	~170 Nm / rad

Electrical / Motor Information

Actuator Model	Approximate Torque Constant	Approximate Speed Constant	Motor Winding Resistance	Gear Inertia @ Motor	Motor Inertia
X5-1	1.1 Nm / A	5.6 RPM / V	10.0 Ω	18 gmm^2	43 gmm^2
X5-4	3.1 Nm / A	2.0 RPM / V	10.0 Ω	16 gmm^2	43 gmm^2
X5-9	7.1 Nm / A	0.9 RPM / V	10.0 Ω	15 gmm^2	43 gmm^2
X8-3	1.6 Nm / A	3.8 RPM / V	5.3 Ω	19 gmm^2	85 gmm^2
X8-9	4.6 Nm / A	1.3 RPM / V	5.3 Ω	14 gmm^2	85 gmm^2
X8-16	8.8 Nm / A	0.7 RPM / V	5.3 Ω	13 gmm^2	85 gmm^2

Reference Frames

The reference frames for the X-Series Actuators are shown in the image below. The origin of the coordinate frames are on the back plane of the housing, centered on the axis of rotation. This is the frame in which the IMU feedback is reported, and it is also the frame that is used for kinematics calculations in the various APIs and the HRDF file format. The coordinate frames are also physically engraved on the housing of each actuator.

Default gains (X-Series)

We have provided downloadable recommended default gains for all control strategies of each of our X-Series modules. Note that these gains should still be tuned for best performance depending on the particular application. For almost all applications we recommend using Strategy 4.

The default gains provided below assume firmware v10 or higher! Using these settings on earlier firmware versions will cause poorly scaled Kd, Ki, and Feedforward gains.

If you have gains that you have tuned for a specific application, that was running on firmware before v10 you can update the values with the following re-scaling:
- All Feedforward gains that are non-zero will get changed to 1.0.
- All Ki gains get multiplied by 1000.
- All Kd gains get multiplied by .001.

For the MATLAB API we have provided a helper function for scaling gains to firmware v10 on all the modules of a given family name, as well as a function for setting the default gains onto a group of modules. For this script to work you will need to download all the individual gain XML files from the table below. You will also need at least the 1.0 version of the Matlab API.

For the C++ API there is a code snippet in the API documentation that shows how to iterate through a group of modules and scale the gains.

Module Type	Strategy 4 (recommended)	Strategy 3	Strategy 2
X5-1	X5-1, Strategy 4	X5-1, Strategy 3	X5-1, Strategy 2
X5-4	X5-4, Strategy 4	X5-4, Strategy 3	X5-4, Strategy 2
X5-9	X5-9, Strategy 4	X5-9, Strategy 3	X5-9, Strategy 2
X8-3	X8-3, Strategy 4	X8-3, Strategy 3	X8-3, Strategy 2
X8-9	X8-9, Strategy 4	X8-9, Strategy 3	X8-9, Strategy 2
X8-16	X8-16, Strategy 4	X8-16, Strategy 3	X8-16, Strategy 2

Wiring

X-Series actuators were designed to simplify traditional wiring pain points and feature a through hole as well as a multi-port switch for daisy chaining. Additionally, we recommend using external power splitters to also daisy chain power wires. They can usually be hidden inside tubes such as shown in the image below.

ext with splitter legend

Wires that come from the previous joint should be inserted directly.	Wires that connect to the next joint should be threaded through the hole.
The T-slot adapter (A-2043-01) has an open side to allow for thru bore access. Try not to pinch wires in this configuration.	Wires from a T-slot adapter should use the base module through bore.

R-Series Actuators

The R-Series Actuators are 'smart' series-elastic actuators that integrate a brushless motor, geartrain, spring, encoders, and control electronics into a compact package that run on standard DC voltages and communicate using standard 10/100Mbps Ethernet over plastic optical fiber (POF). These actuators are designed to function as full-featured robotic components and enable the simultaneous control of position, velocity, and torque. Each actuator also has a wide range of other sensors, all of which can be easily accessed in the the various APIs. Finally, the R-Series Actuators are sealed to IP67 and are designed with a lightweight and rugged form factor that allows them to be used in challenging field applications.

Maximum Performance Range

The chart below indicates, separately, the maximum no-load speed and stall torque capabilities of the different models of R-Series actuators.

For example, an R8-9 is not capable of continuously providing 9 Nm of torque at 30 RPM. It is capable of a continously spinning at maximum speed of 30 RPM at a lower torque, and it is capable of exerting 9 Nm of torque at a lower speed.

More detailed performance information for each actuator is provided in the additional sections below.

Speed-Torque Curves

Each actuator has a range where it can perform continuously, as well as a peak range where it can perform intermittently. While R-Series actuators are rated running at 24V, they are capable of increased intermittent output at higher voltages.

Frequency Response (Bode Plots)

Because the R-Series actuators are mechanically compliant, there is a limit to how rapidly they can react and track to desired commands. Overall, the actuators are designed to be able to replicate human-like motion, but the details of their frequency response depends on the model of the actuator and the details of its commanded action.

The plots below were generated with a mechanically fixed output and tracking a sinusoidal commanded effort of different amplitudes. The ranges shown below are approximate and assume an actuator running at 36V in normal room-temperature conditions without additional cooling. The gains that are used when controlling an actuator greatly effects the frequency response. The plots below use an effort Kp approximately 2X the default value that ships with a new actuator.

Mechanical Information

Actuator Model	Gear Ratio	Spring Stiffness (Non-Linear)	Output Bearing Capacity
R8-3	272.222 : 1	Min: ~50 Nm / rad Max: ~150 Nm / rad	Radial Load Rating Static: 2.2 kN Dynamic: 3.0 kN Axial Load Rating Static: 5.1 kN Dynamic: 6.9 kN Cross-Moment Load Rating Static: 55.6 Nm Dynamic: 75.5 Nm
R8-9	762.222 : 1	Min: ~70 Nm / rad Max: ~700 Nm / rad
R8-16	1462.222 : 1	Min: ~140 Nm / rad Max: ~1400 Nm / rad

Electrical / Motor Information

Actuator Model	Approximate Torque Constant	Approximate Speed Constant	Motor Winding Resistance	Gear Inertia @ Motor	Motor Inertia
R8-3	1.6 Nm / A	3.8 RPM / V	5.3 Ω	11 gmm^2	85 gmm^2
R8-9	4.6 Nm / A	1.3 RPM / V	5.3 Ω	6 gmm^2	85 gmm^2
R8-16	8.8 Nm / A	0.7 RPM / V	5.3 Ω	5 gmm^2	85 gmm^2

Reference Frames

The reference frames for the R-Series Actuators are shown in the image below. The origin of the coordinate frames are on the back plane of the housing, centered on the axis of rotation. This is the frame in which the IMU feedback is reported, and it is also the frame that is used for kinematics calculations in the various APIs and the HRDF file format. The coordinate frames are also physically engraved on the housing of each actuator.

Default gains (R-Series)

We have provided downloadable recommended default gains for all control strategies of each of our R-Series modules. Note that these gains should still be tuned for best performance depending on the particular application. For almost all applications we recommend using Strategy 4.

The default gains provided below assume firmware v10 or higher! Using these settings on earlier firmware versions will cause poorly scaled Kd, Ki, and Feedforward gains.

For the C++ API there is a code snippet in the API documentation that shows how to iterate through a group of modules and scale the gains.

Module Type	Strategy 4 (recommended)	Strategy 3	Strategy 2
R8-3	R8-3, Strategy 4	R8-3, Strategy 3	R8-3, Strategy 2
R8-9	R8-9, Strategy 4	R8-9, Strategy 3	R8-9, Strategy 2
R8-16	R8-16, Strategy 4	R8-16, Strategy 3	R8-16, Strategy 2

Wiring

R-Series actuators were designed to simplify traditional wiring pain points and wire loops by incorporating a through hole. A multi-port switch for daisy chaining POF communication as well as a terminal block for power daisy chaining.

Wiring Block Diagram

Here is a simple Block Diagram showing the wiring setup for the R-Series Actuator. All electronics shall be used with a 24-48V power supply. The communications runs off of 100 Mbps Ethernet converted in the Media Converter to plastic optical fiber (POF) into the actuator.

A POF-Ethernet Media Converter is used to connect the R-Series Actuators to the network. The converter can run off the same 24-48VDC as the actuators and can convert 100 Mbps RJ45 Ethernet communication to 2.2mm plastic optical fiber (POF) communication of the same 100 Mbps Ethernet.

Wires need to be fed thru cord grips for sealing.	Power wires connect to the green terminal block which has 2 ports for each cable enabling daisy-chaining.
There are two OptoLock® connectors for POF communication chaining.	It is best to group the six cables for Power, M-Stop, and POF in the same cord grip to make routing wires more organized.

M-Stop Wiring

An M-Stop (motor-stop) button can be wired to the R-Series actuator’s terminal plug for additional safety. We recommend using a lower voltage (5V) to power the M-Stop for reduced power dissipation. Below are examples of how the MS+ and MS- lines can be wired if you want to use an M-Stop Button in your system:

M-Stop connected to a lower voltage source to reduce power dissipation (preferred configuration).
M-Stop connected to same power supply as the actuator.

The MS+ and MS- lines are the "M-Stop" input for the Actuators. They correspond to the "M-Stop Strategy" setting on the actuators that can be selected from the Scope Application on the 'Gains' Tab shown in the screenshot below:

The actuators can be set to have different behaviors when the M-Stop is triggered, described in the table below.

Make sure to use the "Persist Sends" option when setting the M-Stop Strategy in order to maintain setting after actuator the actuator is reset or turned off and on.

M-Stop Strategy	Description
Disabled	The M-Stop input is ignored. The actuator runs normally no matter what voltage is applied to these lines.
Motor Off	The M-Stop pins require voltage (5V-48VDC) for the actuator to run. When voltage is removed, the motor in the actuator is deactivated (set to Control Strategy Off) and the actuator is backdrivable. The status LED will blink yellow.
Motor Hold	The M-Stop pins require voltage (5V-48VDC) for the actuator to run. When voltage is removed, the motor in the actuator is controlled to maintain its current position. The status LED will blink yellow.

Mechanically Mounting Actuators

The R-Series Actuators have threaded holes for M5 metric screws on their output and bottom sides and four M3 threaded holes on the front plate for mounting. Additionally, there are two 3mm Dowel Pin holes that are spaced 35mm apart symmetric from the center bore on both the output and input interfaces to help with bracket alignment. If you are using standard HEBI connection parts, the appropriate hardware is provided.

Check out the standard R-Series Accessories

Reference Drawing: R8 Dimensional Interface Drawing

Be careful to use the appropriate length screws when mounting the actuators. Using screws that are too long may damage the actuator if they are tightened while bottomed out in the threaded holes.

Be sure to only use Stainless Steel or other Corrosion-Resistant hardware with the actuators. This is to prevent the hardware from seizing due to corrosion.

Sealing Actuators

The R-Series actuators are designed to be sealed to an IP67 rating. In order to achieve the seal, the connector cover needs to be fully installed to the back end of the Actuator.

The connector covers (A-2204-01A and A-2204-01B) have an o-ring that will seal against the back of the actuator. Using the silicone grease in the connection toolbox, fully grease the o-ring before attaching the cover.

If only one cord grip has wires coming through it, replace the unused cord grip insert with a solid plug (PP-2408-01) and tighten down the cord grip.

Lightly pull the slack in the cables through the cord grips to bring the connector cover up agaisnt the actuator. Make sure the terminal block does not disconnect from the actuator.
While holding the connector cover up against the actuator, screw down the captive M3 bolts.

Use a 19mm (or 3/4") open wrench to tighten down the cord grip rubber insert around the wires.

It is important to note that the media converter and other electronics, like the power supply, are not sealed. Make sure there is enough cable length to keep the electronics in some kind of protective case or box if the actuators are being used in a dirty or wet environment.

Internal Pressure

In addition to being sealed for intermittent wet use, R-Series actuators contain an internal pressure sensor that can be accessed on the pressure in the actuator feedback.

Readings are in kPa

The readings from the sensor are absolute pressure, which is the sum of gauge pressure and atmospheric pressure. The reading of an unpressurized actuator will fluctuate slightly with changes atmospheric pressure and temperature.

Standard Reading: ~101 kPa (1 atm or 14.7 psi)
Minimum Internal Pressure : 10 kPa (1.5 psi)
Maximum Internal Pressure : 300 kPa (43.5 psi)

Include a valve

When you are internally pressurizing R-Series actuators it is always good to have some kind of valve incorporated for adding and removing air from the system.

Remember to remove all internal pressure from actuators before disassemblying wiring of actuators. This includes prior to loosening cord grips and screws on connector covers. This will prevent causing harm to yourself or damage to actuator’s o-rings and other components.

In most cases it is best to use the M-stop (blue and yellow) wiring, but if you determine you don’t need it, then you can always loop a wire in the last 2 open cord grip holes to keep the Actuator sealed (shown in image below).

Plug the last Cord Grip with Solid Wire

Even though the R-Series actuators are sealed, air is still able to pass through the wiring of the actuators. Whether you are pressurizing a single or multiple actuators, the last cord grip in your chain should use solid core wire for the power and M-stop lines. This will prevent air from escaping from the pressurized system.

We recommend using the following solid core wires:

Black 18AWG Solid Core Wire: Alpha Wire 6715S BK005
Red 18AWG Solid Core Wire: Alpha Wire 6715S RD005

Solid core wires work well with the WAGO wire nuts and a standard HEBI flying-lead power cable (both included in R-Series standard wiring kit).

Alternative method: custom tether pressurization adapter

As an alternative experiment, a group of 5 actuators were daisy-chained together using the standing wiring cables and a tether pressurization adapter. This custom adapter allows for pressure to be added to the system from the tether instead of the end effector actuator and prevents air from escaping back to your power supply with solid core wire.

A constant air supply of ~250 kPa (absolute pressure) was supplied from the tether with the last module having a solid plug.

The following plots show the difference between using using only stranded wires and using the solid core wires in from the tether pressization adapter.

The POF (plastic optical fiber) cables fully block air flow and do not need to be changed.

From the plot on the left, the pressure drop between actuators in steady-state appears to be correlated to length of wire between the two actuators. The longer the wires, the larger the pressure drop. Additionally, pressure and temperature are directly proportional, as the actuator temperature increases the internal pressure will also increase.

Actuator Feedback

All actuators (both X-Series and R-Series) provide all the feedback below when feedback is requested. Feedback can be requested at rates up to 1 kHz. Wherever possible values are in SI units.

Parameter	Units	Description
`time`	`sec`	The current time from the system clock used by the API. This is a single value that corresponds to all feedback at this timestep.
`pcRxTime`	`sec`	The system time when feedback was received by each module. The most recent of these times is what is reported as the single `time` above.
`pcTxTime`	`sec`	The system time when feedback requests were sent to each module.
`hwRxTime`	`sec`	The hardware timestamp when each module in the group transmitted its feedback. Time initializes at 0 when a module is powered on.
`hwTxTime`	`sec`	The hardware timestamp when each module in the group received a request for feedback. Time initializes at 0 when a module is powered on.

`position`	`rad` or `m`	Sensed position (absolute) of the output of an actuator. X-Series and R-Series Note: The output encoder in these actuators is multi-turn absolute to +/- 4 rotations (8 x 360-degree total range). The encoder knows its position within this range immediately when powering on, even if the actuator is moved while it is not powered. Once the actuator is powered on, it reports its position continuously and unlimited in either direction. If you go outside the +/- 4 rotation range and restart the actuator, the reported position from the encoder will ‘wrap around’ and initialize within +/- 4 rotations.
`velocity`	`rad/sec` or `m/sec`	Sensed velocity at the output of an actuator.
`effort`	`Nm` or `N`	Sensed force or torque (absolute) at the output of an actuator.

`positionCmd`	`rad` or `m`	The currently commanded `position`. If no position is being commanded a value of `NaN` is returned.
`velocityCmd`	`rad/sec` or `m/sec`	The currently commanded `velocity`. If no velocity is being commanded a value of `NaN` is returned.
`effortCmd`	`Nm` or `N`	The currently commanded `effort`. In control `STRATEGY_2`, `3` or `4`, this is a commanded torque or force. In `DIRECT_PWM` mode, this is the commanded `PWM` to an actuator’s motor. If no effort is being commanded a value of `NaN` is returned.
`innerEffortCmd`	`Nm` or `N`	In control strategies 2 and 4, this is the torque or force command going to the inner torque PID loop.
`pwmCmd`	`-1 to 1`	The currently commanded `PWM` being sent to an actuator’s motor, after being modified by any internal safety controllers.

`deflection`	`rad`	The internal deflection of the spring inside an actuator. This value is used with a calibrated spring constant in each actuator to report the actuator’s `effort` feedback.
`deflectionVelocity`	`rad/sec`	The velocity of the internal spring’s deflection.
`motorPosition`	`rad`	The position of an actuator’s internal motor before the gear reduction. Initializes at zero when an actuator is first powered on.
`motorVelocity`	`rad/sec`	The velocity an actuator’s internal motor before the gear reduction.

`accel` or `accelX` `accelY` `accelZ`	`m/sec^2`	A module’s sensed 3-DoF acceleration from an internal IMU, including gravity. Note that this is the sensed motion of the actuator body itself, not the actuator’s output. Depending on the API, XYZ values are combined together into a single vector or returned individually.
`gyro` or `gyroX` `gyroY` `gyroZ`	`rad/sec`	A module’s sensed 3-DoF angular velocity from an internal IMU. Note that this is the sensed motion of the actuator body itself, not the actuator’s output. Depending on the API, XYZ values are combined together into a single vector or returned individually.
`orientation` or `orientationW` `orientationX` `orientationY` `orientationZ`	`unit quaternion`	A module’s 3-DoF orientation based on an onboard complementary filter. The heading component of the estimated orientation will drift over time, as the filter uses only accelerometers and gyros. Depending on the API, quaternion components are combined together into a single vector or returned individually.

`motorCurrent`	`A`	The sensed amount of current an actuator’s motor draws at the bus voltage.
`windingCurrent` or `motorWindingCurrent`	`A`	The estimated of amount current draw of the motor windings internal to the actuator. This value is modeled based on the known motor parameters, internal motor velocity, and current.
`voltage`	`V`	The sensed bus voltage into the module.

`motorTemperature` or `motorSensorTemperature`	`deg-C`	The sensed temperature near the motor in the actuator.
`ambientTemperature` or `boardTemperature`	`deg-C`	The sensed temperature of the electronics in the actuator.
`processorTemperature`	`deg-C`	The sensed temperature of the processor in the actuator.
`actuatorTemperature` or `motorHousingTemperature`	`deg-C`	The modeled housing temperature of the motor inside an actuator.
`windingTemperature` or `motorWindingTemperature`	`deg-C`	The modeled winding temperature of the motor inside an actuator. This value is used by a safety controller that runs in the firmware of an actuator that will limit the `PWM` to the motor if it approaches a critical temperature.

`mStopState`	`enum` or `HebiEnum.MStopState*`	The status of the M-Stop line in the module. `not triggered` `triggered`
`commandLockState`	`enum` or `HebiEnum.CommandLockState*`	The status of the command lockout on the module, active during the `CommandLifetime` of a given command. `not locked (ready to receive commands)` `locked by sender (receiving commands from this group)` `locked by other (commands from this group will be ignored)`
`temperatureState`	`enum` or `HebiEnum.TemperatureState*`	The status of the various temperature safety controllers on the module. `normal` `critical` `exceeds maximum motor temperature` `exceeds maximum board temperature`
`positionLimitState` `velocityLimitState` `effortLimitState`	`enum` or `HebiEnum.PositionLimitState*`	The status of the various motion safety controllers on an actuator. `below lower limit` `at lower limit` `inside range (normal operation)` `at upper limit` `above upper limit` `not initialized`

`LED` or `ledR` `ledG` `ledB`	`0 to 1`	RGB color values of the status LED. Depending on the API, RGB values are combined together into a single vector or returned individually.

`pressure`	`kPa`	Internal absolute pressure of the actuator in kPa. (R-Series Only)

Actuator Commands

The commands that each actuators support for controlling motion are the same as the commands listed in the Groups section of Core Concepts. They are included here for convenience.

Parameter	Units	Description
`position`	`rad` or `m`	The desired position of the output of an actuator.
`velocity`	`rad/sec` or `m/sec`	The desired velocity of the output of an actuator.
`effort`	`Nm` or `N`	The desired torque or force of the output of an actuator. For an actuator in`DIRECT_PWM` control strategy, this will be the desired `PWM` of the motor, from `-1 to 1`.

In addition to commands related to motion, a number of hardware-specific parameters can be commanded and/or set.

Parameter	Units	Description
`name`	`string`	The desired user-settable name that an actuator shows up as in a `Lookup`.
`family`	`string`	The desired user-settable family that an actuator shows up as in a `Lookup`.

`boot`	`boolean`	Boots a module from bootloader mode into application mode.
`reset`	`boolean`	Reboots a module.
`persist`	`boolean`	Saves all the settings and gains that are currently set on a module, so that they are loaded after reboot.

`gains`		All controller parameters are settable in the API. See Parameters and Gains in the Core Concepts section for more information.

`referencePosition`	`rad` or `m`	Sets the current feedback `position` by adjusting the user-settable reference point for the zero position. This persists automatically.
`referenceEffort`	`Nm` or `N`	Sets the current `feedback` effort by adjusting the user-settable reference point for zero effort. This persists automatically.

`ledR` `ledG` `ledB`	`0 to 1`	Override RGB color values of the status LED.

I/O Board

A 2432 01

The HEBI I/O Board is an ethernet-enabled module that allows you to easily integrate various low-level sensors into HEBI’s APIs and framework. This module provides general-purpose analog and digital inputs, digital and PWM outputs, encoder inputs, and exposes in the various HEBI APIs in a way that is syncronized with any other modules on the network. It also includes an IMU and on-board orientation estimate, using the same API format as the X-Series actuator.

Some example uses of the I/O Board:

Reading analog load cells / pressure sensors
Reading signals from limit switches
Reading input from buttons / potentiometers
Reading quadrature encoders
Controlling pneumatic valves (requires external relays)
Controlling solenoids (requires external relays)
Controlling LED lights
Sending digital line signals to other devices

Revisions

Part Number	Description and Downloads	Image
A-2432-01	HEBI I/O Board (Using I/O Micro) User Manual
A-2116-02	HEBI I/O Board (rev C) User Manual Mechanical Drawing
A-2116-01	HEBI I/O Board (rev B) User Manual

Reference Frame

The reference frame for the I/O board’s IMU (accelerometer, gyro, orientation) is shown in the image below. The origin of the coordinate frame is shown centered on the IMU.

I/O Board Feedback

Parameter	Units	Description
`time`	`sec`	The current time from the system clock used by the API. This is a single value that corresponds to all feedback at this timestep.
`pcRxTime`	`sec`	The system time when feedback was received by each module. The most recent of these times is what is reported as the single `time` above.
`pcTxTime`	`sec`	The system time when feedback requests were sent to each module.
`hwRxTime`	`sec`	The hardware timestamp when each module in the group transmitted its feedback. Time initializes at 0 when a module is powered on.
`hwTxTime`	`sec`	The hardware timestamp when each module in the group received a request for feedback. Time initializes at 0 when a module is powered on.

`a1 - a8`	`volts`	8 analog inputs, with a range of 0-5V.
`b1 - b8`	`0 or 1`	8 digital inputs, which can handle either 3.3V or 5V levels.
`c1-c3`	`ticks`	Quadrature encoder input. `c1` and `c2` will both report the incremental count (32 bits), starting at zero on boot. `c3` is for an index pulse and is not currently implemented.
`c4-c6`	`ticks`	Quadrature encoder input. `c4` and `c5` will both report the incremental count (32 bits), starting at zero on boot. `C6` is for an index pulse and is not currently implemented.
`e1 - e8`	`0 or 1`	The currently commanded values on the 8 digital outputs.
`f1 - f8`	`0 to 1`	The currently commanded values on the 8 PWM outputs.

`accel` or `accelX` `accelY` `accelZ`	`m/sec^2`	A module’s sensed 3-DoF acceleration from an internal IMU, including gravity. Depending on the API, XYZ values are combined together into a single vector or returned individually.
`gyro` or `gyroX` `gyroY` `gyroZ`	`rad/sec`	A module’s sensed 3-DoF angular velocity from an internal IMU. Depending on the API, XYZ values are combined together into a single vector or returned individually.
`orientation` or `orientationW` `orientationX` `orientationY` `orientationZ`	`unit quaternion`	A module’s 3-DoF orientation based on an onboard complementary filter. The heading component of the estimated orientation will drift over time, as the filter uses only accelerometers and gyros. Depending on the API, quaternion components are combined together into a single vector or returned individually.

`LED` or `ledR` `ledG` `ledB`	`0 to 1`	RGB color values of the status LED.

I/O Commands

Parameter	Units	Description
`e1 - e8`	`0 or 1`	8 digital outputs, which can output either 3.3V or 5V levels.
`f1 - f8`	`0 to 1`	8 PWM outputs, which can output either 3.3V or 5V levels. They are configured to switch at approximately 20kHz, which is appropriate for most DC motor control applications.

In addition to commands related to I/O a number of other things can be commanded and/or set.

Parameter	Units	Description
`name`	`string`	The desired user-settable name that an actuator shows up as in a `Lookup`.
`family`	`string`	The desired user-settable family that an actuator shows up as in a `Lookup`.

`boot`	`boolean`	Boots a module from bootloader mode into application mode.
`reset`	`boolean`	Reboots a module.
`persist`	`boolean`	Saves all the settings and gains that are currently set on a module, so that they are loaded after reboot.

`LED` or `ledR` `ledG` `ledB`	`0 to 1`	Override RGB color values of the status LED.

Module Info Feedback

All modules (actuators and I/O devices) return feedback that provides information about their hardware, networking paramaeters, and other state like gains and control parameters.

Parameter	Units	Description
`name`	`string`	The current user-settable name that a module shows up as in a `Lookup`.
`family`	`string`	The current user-settable family that a module shows up as in a `Lookup`.

`macAddress`	`XX:XX:XX:XX:XX:XX`	The MAC Address of the module. This is a unique identifier used in Ethernet communication.
`ipAddress`	`XXX.XXX.XXX.XXX`	The IP Address of a module.
`netMask`	`XXX.XXX.XXX.XXX`	The network mask of a module.
`gateway`	`XXX.XXX.XXX.XXX`	The gateway of a module.
`firmwareType`	`X5_8_*`	The specific type of firwmare that a module is currently running.
`firmwareRevision`	`X.XXX.XXX`	The revision number of the firmware that is a module is currently running.

`serialNumber`	`string`	The unique HEBI-assigned serial number for a module.
`mechanicalType`	`string`	The mechanical type of an actuator, for example "X5-1" or "X8-9".
`mechanicalRevision`	`string`	The revision identifier for the mechanical components for a module.
`electricalType`	`string`	The specific type of electronics in a module.
`electricalRevision`	`string`	The revision identifier for the electrical components for a module.

`gains`		All controller parameters are settable in the API. See Parameters and Gains in the Core Concepts section for more information.

Accessories

We offer a wide variety of accessories in order to help build and configure your robot with ease.

If your application requires an accessory that is not listed below, HEBI can provide a quote custom development.

X-Series Accessories

Mechanical Accessories

Additional drawings and CAD models can be accessed at cad.hebi.us.

Part Number	Description and Drawings	Image
A-2138-01	X-Series Gripper Assembly Drawing: A-2138-01
A-2116-01	I/O Board Assembly Drawing: HEBI I/O Board
A-2038-02	X5/X8-Series 1.25" Tube Adapter w/ indexing pins (Output) Assembly Drawing: A-2038-02
A-2039-02	X5/X8-Series 1.25" Tube Adapter w/ indexing pins (Housing) Assembly Drawing: A-2039-02
A-2040-01R	X5/X8-Series 90^o Bracket Heavy Duty (Right) Assembly Drawing: A-2040-01R
A-2040-01L	X5/X8-Series 90^o Bracket Heavy Duty (Left) Assembly Drawing: A-2040-01L
A-2042-01R	X5/X8-Series 90^o Bracket Lite (Right) Assembly Drawing: A-2042-01R
A-2042-01L	X5/X8-Series 90^o Bracket Lite (Left) Assembly Drawing: A-2042-01L
A-2043-01	X5/X8-Series T-Slot Mount Plate 25mm/1" Assembly Drawing: A-2043-01
A-2074-01	X5/X8-Series In-line Tube Adapter (Output) Assembly Drawing: A-2074-01
A-2076-01	X5/X8-Series Wheel Adapter Assembly Drawing: A-2076-01 Example with 8" Wheel
A-2089-01	X5/X8-Series Mid-Tube Adapter (Housing) Assembly Drawing: A-2089-01
A-2090-01	X5/X8-Series Tube Adapter Cover (Output) Assembly Drawing: A-2090-01
A-2091-01	X5/X8-Series Tube Adapter Cover (Housing) Assembly Drawing: A-2091-01

Electrical Accessories

Part Number	Description and Drawings	Image
PP-2059-01 PP-2060-01 PP-2061-01	High-Flex Ethernet Patch Cable PP-2059-01: 12" (300mm) Length PP-2060-01: 24" (600mm) Length PP-2061-01: 36" (900mm) Length
PE-2026-01	X5/8 Power Distribution Board
A-2046-12 A-2046-18 A-2046-24	Female/Female Power Cable A-2046-12: 12" (300mm) Length A-2046-18: 18" (450mm) Length A-2046-24: 24" (600mm) Length
A-2047-12	Female/Flying-Lead Power Cable 12" (300mm) Length
A-2048-02	Male/Male Power Cable 2" (50mm) Length
A-2098-24 A-2098-48	Power Supply w/ Mini-Fit Jr. Terminations 24V DC, 220W 48V DC, 220W

Whenever feasible we try to make all HEBI components compatible with existing standards. While we do offer and sell all of the required parts, below are suggestions for some of the most common items that customers may want get from other sources.

Commercial Off-The-Shelf (COTS)

Type	Comments	Links
Power Supply	24-48 VDC output Even though the peak power draw can be over 50W per actuator, in practice we have found 200W power supplies to be more than sufficient for a typical 4 to 6 DoF arm. Note that the power supply’s connector will need to be changed to be compatible with the `Molex Mini-Fit Jr.` connector	DigiKey 24V DigiKey 36V DigiKey 48V
Network Cables	Slim snag-less Ethernet cables	Amazon US
Power Supply (I/O Board, rev B only)	7V-24 VDC output Compatible with Arduino power supplies

R-Series Accessories

Mechanical Accessories

Additional drawings and CAD models can be accessed at cad.hebi.us.

Part Number	Description and Drawings	Image
A-2292-01	R-Series Gripper Assembly Drawing: A-2292-01
A-2116-01	I/O Board Assembly Drawing: HEBI I/O Board
A-2218-01	R-Series 1.25" Output Tube Adapter w/ indexing pins Assembly Drawing: A-2218-01
A-2219-01	R-Series 1.25" Housing Tube Adapter w/ indexing pins Assembly Drawing: A-2219-01
A-2220-01	R-Series Light 90^o Bracket Assembly Drawing: A-2220-01
A-2221-01	R-Series Heavy 90^o Bracket Assembly Drawing: A-2221-01
A-2228-01	R-Series T-Slot Mount Plate 25mm/1" Assembly Drawing: A-2228-01
A-2225-01	R-Series Output In-line Tube Adapter Assembly Drawing: A-2225-01
A-2227-01	R-Series Wheel Adapter Assembly Drawing: A-2227-01
A-2224-01	R-Series Housing Mid-Tube Adapter Assembly Drawing: A-2225-01
A-2090-01	X5/X8/R8-Series Output Tube Adapter Cover Assembly Drawing: A-2090-01
A-2231-01	R-Series Housing Tube Adapter Cover Assembly Drawing: A-2231-01
A-2232-01	R-Series Heavy 90^o Bracket Cover Assembly Drawing: A-2232-01
A-2235-01	R-Series Light 90^o Bracket Cover Assembly Drawing: A-2235-01

Electrical Accessories

Part Number	Description and Drawings	Image
A-2262-01	R-Series Connection Toolbox R-Series Connection Toolbox BOM
A-2256-01	R-Series Plastic Optical Fiber (POF) Media Converter
PP-2401-DUP	1.0mm x 2.2mm POF Duplex Cable Sold By the Foot
PP-2402-01	POF Termination Cutter
PP-2349-RED PP-2349-BLK	18AWG Power Wire for R-Series Actuator, Bundle of Black and Red Sold By the Foot
PP-2358-YLW PP-2358-BLU	22AWG M-Stop Cable for R-Series Actuator, Bundle of Blue and Yellow Sold By the Foot
A-2098-36	Power Supply w/ Mini-Fit Jr. Terminations 36V DC, 220W

Tubes and Tube Accessories

These Tubes and Tube Accessories are compatible with both X-Series and R-Series Actuators and their corresponding Accessories.

Part Number	Description and Drawings	Image
PM-2200-01	1.25" OD Aluminum Tube w/ indexing holes, 150mm length Drawing: PM-2200-01
PM-2200-02	1.25" OD Aluminum Tube w/ indexing holes, 300mm length Drawing: PM-2200-02
PM-2200-03	1.25" OD Aluminum Tube w/ indexing holes, 500mm length Drawing: PM-2200-03
A-2118-01	Tube-to-Tube T-Adapter for 1.25" OD Tube Assembly Drawing: A-2118-01
A-2129-01	Tube-to-Tube Plus-Adapter for 1.25" OD Tube Assembly Drawing: A-2129-01
A-2095-01	Six Tube Adapter for 1.25" OD Tube Assembly Drawing: A-2095-01

Kits

In addition to individual components, we have designed ready-to-go robotic systems we refer to as "kits". All kits include actuators, connecting accessories, wiring, assembly instructions, and example code.

All kits have a suggested set of HEBI actuators. It is possible to adjust parameters such as payload or speed with a different configuration of actuators.

Table 1. Currently available kits
Part Number	Description and Info	Image
A-2302-01 A-2302-01G* *with HEBI Gripper	4 - Degree of Freedom (DoF) R-Series SCARA Style Arm Kit Assembly Instructions coming soon HRDF file (A-2302-01) HRDF file (A-2302-01G)
A-2240-04	4 - Degree of Freedom (DoF) R-Series Arm Kit Assembly Instructions Datasheet HRDF file
A-2240-05	5 - Degree of Freedom (DoF) R-Series Arm Kit Assembly Instructions Datasheet HRDF file
A-2240-05G	5 - Degree of Freedom (DoF) R-Series Arm Kit with HEBI Gripper Assembly Instructions Datasheet HRDF file
A-2240-06	6 - Degree of Freedom (DoF) R-Series Arm Kit Assembly Instructions Datasheet HRDF file
A-2240-06G	6 - Degree of Freedom (DoF) R-Series Arm Kit with HEBI Gripper Assembly Instructions Datasheet HRDF file
A-2303-01	7 - Degree of Freedom (DoF) R-Series Double Shoulder Arm Kit Assembly Instructions Datasheet HRDF file
A-2257-01	Lily R-Series Hexapod Robot Kit Assembly Instructions Datasheet
A-2084-01 A-2084-01G* *with HEBI Gripper	4 - Degree of Freedom (DoF) SCARA Style Arm Kit Assembly Instructions HRDF file (A-2084-01) HRDF file (A-2084-01G)
A-2085-04	4 - Degree of Freedom (DoF) X-Series Arm Kit Assembly Instructions Datasheet HRDF file
A-2085-05	5 - Degree of Freedom (DoF) X-Series Arm Kit Assembly Instructions Datasheet HRDF file
A-2085-05G	5 - Degree of Freedom (DoF) X-Series Arm Kit with HEBI Gripper Assembly Instructions Datasheet HRDF file
A-2085-06	6 - Degree of Freedom (DoF) X-Series Arm Kit Assembly Instructions Datasheet HRDF file
A-2085-06G	6 - Degree of Freedom (DoF) X-Series Arm Kit with HEBI Gripper Assembly Instructions Datasheet HRDF file
A-2099-07	7 - Degree of Freedom (DoF) X-Series Arm Kit with Double Shoulder Joints Assembly Instructions Datasheet HRDF file
A-2160-01	Rosie Omnidirectional Mobile Manipulation Kit Assembly Instructions Datasheet
A-2049-01	Daisy Hexapod Robot Kit (18-DoF) Out of the Box Manual Assembly Instructions Datasheet Tethered Assembly Instructions (No Longer Sold)
A-2058-02	Igor Balancing Wheeled Robot Kit (14-DoF) Assembly Instructions Datasheet
A-2120-01	Edward Omni-Directional Mobile Manipulator Robot Kit (13-DoF) Assembly Instructions
A-2132-02	Modular Chassis Kit (Square) A great starting point to build your own robotic system. HEBI actuators interface seemlessly with this chassis. Includes: - Structural Chassis made with T-Slot extrusion for easy attachment - Internal computer, Ethernet switch, and wireless adapters for a self-contained wireless robotic system - Bulkhead Connectors to fit every need - Up to 4 batteries Reference Drawing
A-2127-02	Modular Chassis Kit (Hexagonal) A great starting point to build your own robotic system. HEBI actuators interface seemlessly with this chassis. Includes: - Structural Chassis made with T-Slot extrusion for easy attachment - Internal computer, Ethernet switch, and wireless adapters for a self-contained wireless robotic system - Bulkhead Connectors to fit every need - Up to 4 batteries Reference Drawing

Assembly Instructions

Tubing and Tube Adapters

HEBI tubes and tube adapters are an easy way to create systems such as robotic arms. The indexing holes allow for precise length and twist measurements for your robot’s kinematics (see X5 Link in Kinematics section). Our tubes come in standard lengths of 150mm, 300mm, and 500mm, but are easily cut down to custom lengths. Tubes were chosen for their lightweight and thru bore allowing for easy installation of wires (see Module Documentation).

A-2038-02: Output Tube Adapter	A-2039-02: Input Tube Adapter
A-2038-02 Assembly Instructions	A-2039-02 Assembly Instructions

Right Angle Brackets

HEBI right angle brackets allow you to use X-Series actuators in perpendicular axes, commonly needed for bases or end effectors of robotic arms. These brackets come in both a 'Left' and 'Right' configuration making it easy to setup your system specific to your application’s needs.

Lightweight Bracket

These brackets are 3D printed glass-filed nylon and are best for connecting end effectors to a final "wrist" degree of freedom on robotic arms.

A-2042-01L: Lightweight Right Angle Bracket (Left)	A-2042-01R: Lightweight Right Angle Bracket (Right)
A-2042-01L Assembly Instructions	A-2042-01R Assembly Instructions

Heavy Duty Bracket

These brackets are black anodized aluminum and are best for bases of robotic arms. You can mount the vertical actuator in an 'inside' or 'outside' configuration as shown below.

A-2040-01L: Heavy Duty Right Angle Bracket (Left)	A-2040-01R: Heavy Duty Right Angle Bracket (Right)
A-2040-01L Assembly Instructions	A-2040-01R Assembly Instructions

T-Slot Adapter

Need an easy solution for mounting your robotic system? Enjoy building structures out of t-slot aluminum extrusion? The t-slot adapter is for you! This plate helps you attach any X-Series actuator to standard 25mm or 1 inch t-slot aluminum extrusion.

A-2043-01: T-Slot Aluminum Adapter Plate
A-2043-01 Assembly Instructions

Kinematic Information

X5 and X8 Actuators

X5 and X8 Output X5 Side View	X5 and X8 Input X8 Side View

There are no dedicated X8-Link or X8-Bracket parts. The housings of X5 and X8 actuators have the same input and output interface, so the X8 actuators are compatible with X5 connection parts.

X5 Link

The X5 Link represents a straight extension that is typically used to connect two X-Series actuators. It consists of input and output adapters, as well as a hollow tube that cables can be wired through. It is defined by the extension length as well as the twist angle to the next output.

X5 Link angled forward view

Parameter	Description
`Extension`	Defined as the center to center distance in meters between rotating axes of the actuator. It is along the X-axis of the link (red axis in the above image). Depending on the type of tube that is being used there are two common ways for calculating the correct distance: Generic tubes: `x + 0.025` where `x` is the distance between the outer-most tube parts. Indexed tubes: `(N+1) * 0.025` where `N` is the total number of holes on the tube. For example, a 300mm tube section has 12 holes, so the total distance would be `13 * 0.025 = 0.325m`.
`Twist`	Rotation about the X-axis (red axis in the above image). For example, the images above show a twist of PI radians.

The examples below illustrate the possible variations for the Twist parameter in combination with a 300mm tube (extension=0.325m).

`Twist = 0` `Twist = +/-PI`	`Twist = +PI/2` `Twist = -PI/2`

Inline Tube Adapters

An additional attribute for X5 links which is now supported is an inline link adapter for both the output and housing side of actuators. Find out more about these attributes in the HRDF Link format documentation.

Input is defined as the proximal adapter to the link, whereas Output is defined as the distal adapter to the link.

`Twist = 0` `Input = RightAngle` `Output = RightAngle` `Twist = 0` `Input = RightAngle` `Output = Inline`	`Twist = 0` `Input = Inline` `Output = RightAngle` `Twist = 0` `Input = Inline` `Output = Inline`

X5 Light Bracket

The X5 Light Bracket corresponds to a light-weight right-angle adapter that is typically used at the wrist of an arm. It has a single parameter that specifies the mounting direction.

Parameter	Description
`Mounting`	The direction of the output 'Z' axis (blue) pointing towards the next module, assuming that the 'X' axis (red) is pointing forward and the position is zero. The two possible configurations are: `left` `right`

Note that the left and right configurations are physically different parts, rather than the same part mounted in a different orientation.

The below images show both mounting configurations at an output position of zero.

`Mounting = "left"` Part Number: A-2042-01L	`Mounting = "right"` Part Number: A-2042-01R

X5 Heavy Bracket

The X5 Heavy Bracket type corresponds to a sturdy right-angle adapter that is typically used at the base of a robot arm configuration. It has a single parameter that specifies the mounting direction.

Parameter	Description
`Mounting`	Due to the modular design of the bracket there are four different configurations. This parameter describes the output direction (same as the light bracket above) as well as the mounting side (closer or further away from the center). The four possible configurations are `left-outside` `left-inside` `right-inside` `right-outside`

Note that the left vs right portion of the configurations are physically different parts, and the inside vs outside portion of the configuration describe the two different ways a given bracket can be assembled.

The below images show the four possible mounting configurations at an output position of zero.

`Mounting = "left-outside"` `Mounting = "left-inside"` Part Number: A-2040-01L	`Mounting = "right-outside"` `Mounting = "right-inside"` Part Number: A-2040-01R

R8 Actuators

R8 Output R8 Side View	R8 Housing R8 Connector Cord Grip View

The R8-Link is very similar to the X5-Link, but is encoded to only fit with R-Series parts. The housings of R8 actuators have the same output interface as X-Series actuators with the addition of M3 dowel pin and slot interfaces, but the housing interface is now actually symmetric about the bore hole where in X-Series actuator the housing bolt pattern has a 2mm offset.

R8 Link

The R8 Link represents a straight extension that is typically used to connect two R-Series actuators. It consists of input and output adapters, as well as a hollow tube that cables can be wired through. It is defined by the extension length as well as the twist angle to the next output.

r8 link angled forward view

Parameter	Description
`Extension`	Defined as the center to center distance in meters between rotating axes of the actuator. It is along the X-axis of the link (red axis in the above image). Depending on the type of tube that is being used there are two common ways for calculating the correct distance: Generic tubes: `x + 0.025` where `x` is the distance between the outer-most tube parts. Indexed tubes: `(N+1) * 0.025` where `N` is the total number of holes on the tube. For example, a 300mm tube section has 12 holes, so the total distance would be `13 * 0.025 = 0.325m`.
`Twist`	Rotation about the X-axis (red axis in the above image). For example, the images above show a twist of PI radians.

The examples below illustrate the possible variations for the Twist parameter in combination with a 300mm tube (extension=0.325m).

`Twist = 0` `Twist = +/-PI`	`Twist = +PI/2` `Twist = -PI/2`

Inline Tube Adapters

An additional attribute for R8 links which is now supported is an inline link adapter for both the output and housing side of actuators. Find out more about these attributes in the HRDF Link format documentation.

`Twist = 0` `Output = RightAngle` `Input = RightAngle` `Twist = 0` `Output = RightAngle` `Input = Inline`	`Twist = 0` `Output = Inline` `Input = RightAngle` `Twist = 0` `Output = Inline` `Input = Inline`

R8 Light Bracket

The R8 Light Bracket corresponds to a light-weight right-angle adapter that is typically used at the wrist of an arm. It has a single parameter that specifies the mounting direction.

Parameter	Description
`Mounting`	The direction of the output 'Z' axis (blue) pointing towards the next module, assuming that the 'X' axis (red) is pointing forward and the position is zero. The two possible configurations are: `left` `right`

Note that the left and right configurations are the same part mounted in a different orientation.

The below images show both mounting configurations at an output position of zero.

`Mounting = "left"` Part Number: A-2220-01	`Mounting = "right"` Part Number: A-2220-01

R8 Heavy Bracket

The R8 Heavy Bracket type corresponds to a sturdy right-angle adapter that is typically used at the base of a robot arm configuration. It has a single parameter that specifies the mounting direction.

Parameter	Description
`Mounting`	Due to the modular design of the bracket there are four different configurations. This parameter describes the output direction (same as the light bracket above) as well as the mounting side (closer or further away from the center). The four possible configurations are `left-outside` `left-inside` `right-inside` `right-outside`

Note that the left vs right portion of the configurations are the same part with a symmetric gas spring mounting, and the inside vs outside portion of the configuration describe the two different ways a given bracket can be assembled.

The below images show the four possible mounting configurations at an output position of zero.

`Mounting = "left-outside"` `Mounting = "left-inside"` Part Number: A-2221-01	`Mounting = "right-outside"` `Mounting = "right-inside"` Part Number: A-2221-01