大跨度完全约束空间3-DOF柔索驱动并联机器人稳定性灵敏度研究

Stability sensitivity of a completely restrained 3-DOF cable-driven parallel robot with four long-span cables

由于驱动柔索的柔性和单向约束特性,以及柔索悬垂的影响,大跨度完全约束空间3-DOF柔索驱动并联机器人稳定性面临着严峻挑战。该文建立此种机器人的稳定性评价模型及其稳定性灵敏度分析模型,探索并分析末端执行器位置和柔索驱动力等因素对机器人稳定性的影响程度。首先,基于机器人运动学和动力学模型,提出稳定性位置和柔索驱动力影响因子,建立稳定性评价模型。其次,采用灰色关联分析方法建立机器人稳定性灵敏度分析模型,提出采用关联度研究和衡量机器人末端执行器位置和柔索驱动力等参数对机器人稳定性的影响程度。最后,以大跨度4索驱动摄像机器人为例,对所建立的稳定性评价模型和敏感度分析模型进行仿真研究。结果表明:摄像机器人稳定性对驱动力影响因素的敏感度较大,其次为位置影响因素,其中稳定性对末端摄像平台y方向位移的关联度最小。研究结果为大跨度完全约束空间3-DOF柔索驱动并联机器人运动轨迹的稳健优化设计与运动控制提供了指导方向。

The stability of a completely restrained 3-DOF cable-driven parallel robot with four long-span cables, due to the flexibility and unidirectional restraint characteristics of the cables, as well as the influence of the large-span cable sags, faces severe challenges. This paper establishes the stability evaluation model and stability sensitivity analysis model for the robot, explores and analyzes the influence of the end-effector positions and the cable tensions on the stability of the robot. Firstly, based on kinematics and dynamics model of the robot, the stability position influence factor and the cable tension influence factor are proposed, and furthermore, the stability evaluation model is established. Secondly, the gray correlation analysis method is used to establish the stability sensitivity analysis model for the robot, and it is proposed to use the correlation degree to study and measure the influence degree of the end-effector positions and cable tensions on the stability of the robot. Finally, the established stability evaluation model and sensitivity analysis model are simulated for a cable-driven camera robot with four long-span cables. The research results show that the stability of the camera robot is more sensitive to cable tension influence factors. Among them, the stability has the smallest correlation to the y-direction displacement of the camera platform. This research provides guidance for the robust optimization design of the motion trajectory and motion control for the robot.