Biped Robot 6dof - weight: 1,34kg
For this picture the robot was held by a string.
Biped Robot CAD model
- this page describes all the components that are required to build the Biped Robot
- each leg has 3 active degrees of freedom and a passive ankle joint
- the legs of the Biped Robot are described here: Biped Leg 3dof v1 Documentation
- compared to the quadruped robots the upper and lower leg length was increased by 25% - from 160mm to 200mm
- since the biped has no leg rotation degree of freedom the yaw angle of the robot cannot be controlled
- the line contact of the feet help to stabilize the yaw orientation of the robot
- the onboard IMU and the Vicon Markers on the body are used for base estimation
- the interface wire provides power and ethernet communication
Biped Robot 6dof - front view
For this picture the robot was held by a string.
Biped Robot 6dof - back view
For this picture the robot was held by a string.
Biped Robot 6dof - sitting posture
Biped Robot Dimensons
Biped Robot Hip Height - at 45°, 60° and 90° lower leg angle
Biped Leg Modules - right side and left side - 540g each
- the legs of the Biped Robot are described here: Biped Leg 3dof v1 Documentation
- all the internal components of the actuator modules are identical
- the internal components of the actuator modules are described here:
- the preparation of the actuator modules is described here:
Biped Body Structure Assembled - weight: 99g
- the 3d printed parts of the body module are listed below
- the preparation of the 3d printed parts is described below
Electronic Component Overview
Electronic Components Biped Robot
Master Board v2 - weight: 19g each
- Custom electronics board: Master Board Documentation
Micro Driver Boards v2 - stack with 3 cards - weight: 47g
- Custom electronics board: Micro Driver Board Documentation
- Lord Microstrain 3DM-CX5-25
- Weight: 13g
- Lord Microstrain webpage
- ordering information below
Parts Body Structure - weight: 87g
The recommended printing direction for all the parts below is the positive z direction of the stl files.
All the STL files for 3d printing the body structure can be found here: STL Files Biped Body Structure.
The preparation of the 3d printed parts is described below: Preparing the 3D Printed Parts
More information about 3d printing can be found here: Details 3D Printed Parts
- Body Structure Front - STL file
- weight: 19g
- Body Structure Back Rev A- STL file
- weight: 14g
- Body Structure Right Side - STL file
- weight: 9g
- Body Structure Left Side - STL file
- weight: 9g
- Body Structure Bottom - STL file
- weight: 17g
- there are 4 different versions of the Body Structure Top element available
- minimal version, with IMU, with Vicon markers and with IMU and Vicon markers
- Body Structure Top - STL file
- weight: 14g
- Body Structure Top Vicon - STL file
- weight: 15g
- Body Structure Top IMU - STL file
- added IMU attachment to the top structure
- weight: 15g
- Body Structure Top IMU Vicon - STL file
- added IMU attachment to the top structure
- weight: 16g
- Micro Driver Stack Spacer - STL file
- weight: 0,2g
- Stand Attachment - STL file
- weight: 23g
- Dimensions: 25mm x 20mm x 4mm
- Stainless steel
- Weight: 3,4g each
- Ordering information below
- M2, M2,5 and M3 fasteners for the biped robot
- we use stainless steel fasteners
- Ordering information below
- fasteners for the IMU
- M2,5x16 Slotted Screw - Polyamide Plastic
- Weight: 0,1g each
- Ordering information below
- we use Helicoil inserts to reinforce the threads of the 3d printed parts
- you need the Helicoil Tools to install the threaded inserts
- Helicoil ordering information below
Reflective markers for motion capture system - weight: 1g each
- 9.5mm Vicon Markers on the base
- M4 x 10 set screws for a attachment
- Weight: 1g each
- Optional - only required for motion capture system
- Ordering information below
| Description | Quantity | Ordering Information | Comments |
|---|---|---|---|
| Biped Leg 3DOF Right Side | 1 | Biped Leg 3DOF Documentation | Custom assembly |
| Biped Leg 3DOF Left Side | 1 | Biped Leg 3DOF Documentation | Custom assembly |
| Master Board v2 | 1 | Master Board Documentation | Custom electronics |
| Micro Driver Board v2 | 3 | Micro Driver Documentation | Custom electronics |
| Inertia Measurement Unit | 1 | Lord Microstrain 3DM-CX5-25 Distributors |
Extended measurement range: Gyro Rate: +/- 900 deg/sec. Accelerometer range: +/- 20G |
| Body Structure Front | 1 | STL file | 3d printed part |
| Body Structure Back Rev A | 1 | STL file | 3d printed part |
| Body Structure Right Side | 1 | STL file | 3d printed part |
| Body Structure Left Side | 1 | STL file | 3d printed part |
| Body Structure Bottom | 1 | STL file | 3d printed part |
| Body Structure Top | 1 | STL file | 3d printed part Alternatives below |
| Body Structure Top Vicon | 1 | STL file | 3d printed part With Vicon marker attachments |
| Body Structure Top IMU | 1 | STL file | 3d printed part With IMU attachment |
| Body Structure Top IMU Vicon | 1 | STL file | 3d printed part With IMU and Vicon marker attachment |
| Master Board Protection | 1 | STL file | 3d printed part |
| Micro Driver Stack Spacer | 8 | STL file | 3d printed part |
| Hip AA Bearing 25mm x 20mm x 4mm ET2520 2Z VA |
2 | Emiliana Cuscinetti Doppiaemme EZO USA SBN |
Italy: Emiliana Cuscinetti or Doppiaemme USA: EZO USA All other countries: Send an email to [email protected] and ask for a quote - they ship worldwide. SBN # C07024 We use stainless steel bearings. |
| Vicon Markers Ø 9,5mm | 8 | Vicon Distributors | Reflective Vicon Marker, solid, on plastic foot, Ø 9,5mm |
| Fasteners Vicon Markers M4x10 Set Screw |
8 | Online Schrauben | Stainless steel. Online Schrauben ships within Europe. |
| Fasteners Body Structure M3x8 Socket Head Cap Screw |
18 | Online Schrauben | Stainless steel. Online Schrauben ships within Europe. |
| Fasteners Hip AA Modules M3x8 Socket Head Cap Screw |
6 | Online Schrauben | Stainless steel. Online Schrauben ships within Europe. |
| Fasteners Micro Driver Stack M2,5x25 Socket Head Cap Screw |
4 | Online Schrauben | Stainless steel. Online Schrauben ships within Europe. |
| Fasteners Master Board M2x5 Socket Head Cap Screw |
2 | Online Schrauben | Stainless steel. Online Schrauben ships within Europe. |
| Fasteners Master Board M2x20 Socket Head Cap Screw |
2 | Online Schrauben | Stainless steel. Online Schrauben ships within Europe. |
| Fasteners IMU M2,5x16 Slotted Screw |
3 | Conrad 839940-62 | Polyamide Plastic Shorten to 13mm |
| Helicoil M3 x 4,5mm | 24 | RS 470-838 Hoffmann 082812 M3 |
1,5xD Böllhoff 41890030045 |
| Helicoil M2,5 x 3,75mm | 4 | RS 470-856 Hoffmann 082812 M2,5 |
1,5xD Böllhoff 41890250375 |
Biped Wiring
| Description | Wire Length | Comments |
|---|---|---|
| Hip AA Motor Phases | 20cm | RHAA and LHAA |
| Hip AA Encoder Wire | 28cm | RHAA and LHAA |
| Hip FE Motor Phases | 27cm | RHFE and LHFE |
| Hip FE Encoder Wire | 33cm | RHFE and LHFE |
| Knee Motor Phases | 35cm | RK and LK |
| Knee Encoder Wire | 42cm | RK and LK |
More wiring information: Details Wiring
| Description | Quantity | Wire Length | Comments |
|---|---|---|---|
| Ethernet Wire | 1 | 6m | 4 conductors Details Wiring |
| Power Wires | 2 | 6m | 24V and ground Details Wiring |
| Description | Quantity | Wire Length | Comments |
|---|---|---|---|
| SPI Wires | 3 | 10cm | 5 conductors Details Wiring |
| Description | Quantity | Wire Length | Comments |
|---|---|---|---|
| IMU Wire | 1 | 25cm | 4 conductors Details Wiring |
| Description | Quantity | Wire Length | Comments |
|---|---|---|---|
| Motor Phase Wires | 18 | 11cm | Details Wiring |
Body Structure Top element with Vicon markers - weigth: 23g
Biped body structure with Vicon markers - weight: 106g
Vicon marker positions - Click on picture above to view the PDF drawing
- You can download the Vicon object here: Biped Vicon Object
- more information about the conventions that we use for our robots: Conventions
IMU position - the IMU is colored red in the screenshot above
- the IMU is mounted to the top element of the body structure
- the label on the IMU is pointing downwards (see picture below)
- the coordinate systems of the IMU and the Biped Robot have the same orientation - more information here: Coordinate System Conventions
- the offset between the coordinate systems is documented below
- the IMU origin is not in the geometrical center of the IMU
- IMU Technical Drawing - see Page 2
| IMU Origin Position in the Robot Coordinate System |
X | Y | Z |
|---|---|---|---|
| -0,13mm | -6,35mm | 77,40mm |
Click on picture above to view the PDF drawing.
- The simplified STL files for visualization and simulation can be found here: STL Files Visualization
Biped Inertia Parameters - Click on picture to view PDF document.
Biped Robot 6dof - on stand
| Description | Quantity | Ordering Information | Comments |
|---|---|---|---|
| Stand Attachment | 1 | STL file | 3d printed part |
| Aluminum Profile Back | 1 | Item 7.0.000.09 | Size 8 - 40mm x 40mm Length: 70cm |
| Aluminum Profile Top | 1 | Item 7.0.000.09 | Size 8 - 40mm x 40mm Length: 25cm Tap M8x1,25 |
| Aluminum Profile Bottom | 1 | Item 7.0.000.09 | Size 8 - 40mm x 40mm Length: 30cm |
| Aluminum Profile Side | 1 | Item 7.0.000.09 | Size 8 - 40mm x 40mm Length: 45cm |
| Angle Bracket | 4 | Item 0.0.411.15 | 90 degree angle bracket 40mm |
| End Caps | 4 | Item 0.0.026.01 | Size 8 |
| Rubber Feet | 3 | RS 173-5948 | 20,6mm x 20,6mm x 7,6mm |
| Helicoil M4 x 6mm | 1 | RS 471-005 | 1,5xD Böllhoff 41890040006 M4 Helicoil Tools required. |
| Fastener Stand Attachment M8x25 Flat Head Screw |
1 | Online Schrauben | Stainless steel. Online Schrauben ships within Europe. |
| Fastener Stand Interface M4x40 Socket Head Cap Screw |
1 | Online Schrauben | Stainless steel. Online Schrauben ships within Europe. |
| Fastener Stand Interface M4 Locknut |
1 | Online Schrauben | Stainless steel. Online Schrauben ships within Europe. |
Adjust the distance between the screw head and the 3d printed part to about 6,3mm and tighten the lock nut.
Tap a M8x1,25 thread into the center hole of the top profile.
Install the Stand Attachment with a M8x25 Flat Head Screw.
Body Structure Back on Stand Attachment.
Biped Robot 6dof - Click on the picture to view the biped cad model in your browser
The Solidworks CAD files are available here: Biped 6dof v1 Solidworks CAD files
Felix Grimminger
BSD 3-Clause License
Copyright (c) 2019-2021, Max Planck Gesellschaft and New York University
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