Quad B12

Quadrupedal Research Platform

Technical Details

Size: 0.50 X 0.35 X 0.35 m
Weight: 10.5 kg
Power supply:
18-24 Volts
Actuation/ Engine:
12 x quasi direct drives (gear ratio 1:6) from mjbots
IMU from pi3hat mjbots
400-600 Hz control frequency over CAN

Organisational Details

Application Field: Underactuated Robotics
SAR- & Security Robotics
Space Robotics
Related Projects: AAPLE
Expanding the Action-Affordance Envelope for Planetary Exploration using Dynamics Legged Robots (03.2023- 02.2025)

System description

CAD model of the quadruped (Photo: Heiner Peters, DFKI GmbH)

Quad B12 is a quadrupedal research platform being built in the Underactuated Lab at DFKI RIC. The system is a small and agile four-legged robot, equipped with 12 quasi direct drives (gear ratio 1:6), providing good mechanical transparency and back drivability. 
All four legs have an identical kinematic structure. Two hip joints are connected directly to the flanges of the drive units. The position of the knee drive has been shifted to the hip axis, whereby the drive is coupled to the knee axis by a timing belt with an additional ratio of 1:2. All three joints of a leg form a serial kinematic chain. The thigh and lower leg each have a length of 150 mm and are made of carbon fiber reinforced plastic. All structures of the robot were designed in such a way that they can be produced cost-effectively on a water jet cutter. 
The robot has 18 degrees of freedom (DoF), 3 actuated DoF per leg and 6 underactuated DoF. It has an onboard power supply, a power distribution board and a raspberry pi that controls the robot. Among sensors, it has an Inertial Measurement Unit (IMU), and all the actuators have position, velocity, and torque sensing. The research platform will allow researchers to test their respective controllers and push the quadrupedal research.


Quad B12: Initial Developments

The DFKI Quad B12 robot is an exciting research platform under development in the Underactuated Lab at DFKI RIC. The video showcases a range of behaviors that have been implemented on this quadrupedal robot.

Back to the list of robot systems
last updated 07.11.2023