Testbench for a robot arm Variable-Stiffness Actuator (VSA)¶
Description¶
Variable-Stiffness Actuators (VSA) are used in robot arms to regulate the physical spring-characteristics (stiffness) of a given joint in real-time. For example, when there is a desire to provide some softness/passive compliance to be able to absorb impacts (typically when moving fast and/or with uncertain sensory information), while stiffening up when there is a requirement for precision.
A previous project at the University of Plymouth in the UK developed a 7 DOF robot arm with 5-6 VSAs, which is easy to manufacture with regular FFF 3D printers: https://mstoelen.github.io/GummiArm/ The spin-out company Fieldwork Robotics Ltd works (with HVL) to apply such robot arms in picking berries, fruit and vegetables in horticulture.
However, to fully understand such actuators, and to use them in teaching, we would like to build a fixed testbench for 1 joint with such a VSA (3D printed, with composite tendons, and Dynamixel digital servomotors). This project is about planning, designing and implementing such a testbench, which should include an ability to measure position, velocity and torque at the output.
Please contact me at martin.fodstad.stolen@hvl.no if you are interested in knowing more about this project.