Abstract: To reduce the energy consumption of DELTA robot in high speed operations,the optimization research for high speed pick-and-place trajectories was conducted.The right angle transitions of Adept Cycle were smoothed with Lamé,Clothoid and piecewise polynomials for the planning of trajectories in 3D space.The interpolation points' positions,velocities and accelerations with respect to the one-dimensional incremental displacement along a pick-and-place curve were obtained based on Bang-bang,7th order polynomial and 6th order polynomial.The DELTA robot's kinematics and dynamics models were built to calculate the values of velocity and torque in joint motor space.To optimize the geometric parameters of nine trajectories,two energy-based indices were utilized,which included the input electrical power of servo motors and the robot's mechanical power.In the process of calculating energy consumption,an improved calculation method of robot energy consumption index was proposed by taking the regenerative energy problem of motor into consideration.The result had been verified on an experimental platform of DELTA robot,and the trajectory with minimum energy consumption had been found through the experimental data.A comparison study showed that the piecewise polynomial curve with Bang-bang motion profile was the optimal one with the repeatability of space and time in all nine kinds of trajectories.

Key words: DELTA parallel robot, pick-and-place trajectory, energy index, optimization to the parameters of trajectories

摘要： 为了减少DELTA机器人高速工作时的能耗,对该机器人拾放轨迹的优化问题进行了研究。基于Lamé,Clothoid,分段多项式解决Adept Cycle轨迹的直角过渡问题,实现对轨迹的三维形状规划;基于Bang-bang,7次多项式与6次多项式解决轨迹插补点位置、速度、加速度的设计,实现对轨迹的一维位移与速度的规划。仿真通过DELTA机器人的运动学与动力学模型,求解映射到驱动关节上的速度与力矩分量,并参考电机输入电能与机器人机械能耗两种能耗指标对9种轨迹进行几何参数优化。在计算能耗的过程中考虑电机再生能量的问题,对现有的能耗计算方式进行了改进。在已搭载DELTA的平台上进行测试,验证仿真结果,找出具有最低能耗的轨迹。经过比较发现9种轨迹中,Bang-bang运动规律的分段多项式曲线为最优轨迹,且具有空间与时间可重复性。

关键词: DELTA并联机器人, 拾放轨迹, 能耗指标, 轨迹参数优化