|Title||Actuator design for high force proprioceptive control in fast legged locomotion|
|Publication Type||Conference Paper|
|Year of Publication||2012|
|Authors||Seok, S., A. Wang, D. Otten, and S. Kim|
|Conference Name||Intelligent Robots and Systems (IROS), 2012 IEEE/RSJ International Conference on|
|Conference Location||Vilamoura, Portugal|
High speed legged locomotion involves high acceleration and extensive loadings of the leg, which impose critical challenges in actuator design. We introduce actuator dimensional analysis for maximizing torque density and transmission `transparency'. A front leg prototype developed based on insight from the analysis is evaluated for direct proprioceptive force control without force sensors. The vertical stiffness controlled leg was tested on a material testing device to calibrate the mechanical impedance of the leg. By compensating transmission impedance from commanded torque, the leg was able to estimate impact force. For the impact test, the mean absolute error as a ratio of full scale sensor force is 0.041 in the 3406 N/m stiffness experiment and is 0.049 in the 5038 N/m experiment. The results indicate that prescribed force profile control is possible during high speed locomotion.