基于柔顺控制的航天器大部件机器人装配技术

Robotic Assembly Technology for Heavy Component of Spacecraft Based on Compliance Control

针对航天器大部件装配需求,给出一套基于力/位控制的机器人柔顺装配方法。基于装配界面作用力方向及机器人工具坐标系方向,实时计算用于力/位控制的笛卡尔坐标系。为避免力控制过程中的机器人抖动,设计了力与机器人速度的“S”型关系曲线。针对自由空间力控制、销钉导向等典型应用需求给出了力/位控制策略。针对机器人负载发生变化情况下的界面分离问题,对机器人在装配不同阶段下负载的质量特性进行预先测量,在界面分离时进行负载质量特性参数的切换,实现对应负载的重力补偿,并采用柔顺控制方法释放待分离界面的作用力,最终实现界面安全分离。试验结果表明,采用所设计的力/位控制方法,在工件安装的各主要过程中,工件可以稳定顺应外部约束,最终安装到位,在界面分离阶段,所述方法可以有效释放界面作用力,实现界面安全分离。

For the installation of large and heavy components in spacecraft, a set of methods of compliant robotic assembly based on force/position hybrid control are given. Based on the direction of interface force and the tool coordinate system of robot, the Cartesian coordinate for hybrid force/position control can be computed. The "S"-type curve between robot speed and force is designed to avoid the jitter of robot during force control. For the force control of free space and pin oriented assembly respectively, force/position hybrid control strategies are given. In order to release the force between the separation interfaces when the robot load is changed, the mass characteristics of robot load in different assembly stages are measured in advance, and the mass characteristic parameter is switched before interface separation to compensate the load gravity, then compliance control is used to release the interface force. The experimental results show that the workpiece can stably conform to the external constraints in the installation, and reach the required position, in the interface separation stage, the interface force can be released effectively, and the security separation can be realized.