Weight Lifting Trajectory Optimization for Variable Stiffness Actuated Robot

Table 1

Simulation parameters.

Symbol	Parameter	Value/Unit
	weight factor of duration	0.5
	weight factor of energy cost
	weight factor of payload	2
	maximum deformation of elastic element
	stiffness coefficient in motor position controller
	damping coefficient in motor position controller
	characteristic coefficient of cam disk curve	12
	the optimization tolerance
	the moment arm of elastic torque	33
	spring stiffness	8000
	bounds of the maximum output torque
	bounds of stiffness motor angle
	bounds of stiffness motor velocity
	bounds of stiffness motor acceleration
	viscous friction coefficient
	mass of link1 and link2
	inertia of link1 and link2
	length of link1 and link2
	the center of mass of link1 and link2
	initial state
	terminal state