Automating perturbation experiments for a hopping robot using a cable-driven impedance haptic device

DARPA Robotics Challenge revealed a need for testing/perturbing robots in systematic methods and testing robots in different environments. The goal of this research is to design a testbed that can render virtual dynamics to emulate different environments on a robot and perturb it in a systematic method. A novel perspective of a haptic system is proposed in which a robot is considered as the “user” and the testbed motors are considered as the “haptic device”. Similar to a generic haptic device, the testbed motors will render forces that would be present if the robot were directly interacting with a virtual environment. A cable-driven testbed for a 1 DOF jumping robot (hopper) is introduced and a model-based force control is used to control the haptic device. Next, the performance of the haptic device is characterized by using a sum of sines trajectory with FFT algorithm. The result yields that the haptic system will apply 13N of force error to the hopper. Finally, the testbed is tested with the hopper in the loop by performing two tests: haptic devices applying a zero net force and applying a positive net force.

Affiliated Students and Faculty: Liam HanSam Burden 

Related Media: