多运动态可重构轮履复合式机器人机械设计

Machine design of a reconfigurable wheel-track hybrid mobile robot with multi-locomotion

摘要:

针对复杂的室外地形特征，结合轮式、履带式移动机构的运动优点，提出并研制一种可重构的具有多种运动模式的轮-履复合机器人.该机器人由控制单元、两个相同的可重构车轮、翻转机构和车体组成，具有轮式、履带式、翻转式3种运动模式.轮式工作形态, 机器人为两轮机器人, 运行速度快, 可全方位运动；履带工作状态，机器人可以适应砾石地、沙地、草地等多种复杂地形，具备较强的越障能力；翻转工作状态，履带轮整体翻转，可跨越栏杆等垂直障碍.机器人轮-履转换由车轮内部的并联四连杆机构实现，可根据地面特征选择运行模式，根据障碍类型选择越障方式.在建立运动学和力学模型的基础上，结合数字仿真方法对结构进行了参数化研究，此设计方法优化了转换机构的运动轨迹，降低了对驱动电动机的性能要求，提高了电动机的使用效率.试验表明，机器人可通过调整自身机构以合理的运动模式通过沙地、草地等路面环境，攀越阶梯和栏杆等复杂障碍，具有良好的环境适应性和越障性能，验证了该移动平台系统设计的合理性.

Abstract:

To access the complex and unpredictable environment, a reconfigurable wheel-track robot with multiple locomotion modes is developed. It has the merits of both the wheel mechanism and the track mechanism. The robot consists of a control system unit, two symmetric reconfigurable wheels, rollover mechanism and robot body and has three locomotion modes-wheel mode, track mode and rollover mode. In the wheel locomotion mode, it is an omnidirectional two-wheel robot which can achieve high speed. In the track locomotion mode, the robot has a strong obstacle-climbing capability to complex terrain such as gravel road and grass. In the rollover locomotion mode, the robot rolls over to cross vertical obstacle. It can change its locomotion mode by the transformable parallel four-bar linkage according to the complex terrain. Based on the kinematic and mechanical models, optimization design for mechanism was subsequently carried out integrated with numerical simulations. The proposed mechanism can optimize the movement trajectory of transformation mechanism, reduce the performance requirements of motor and improve the motor service efficiency. Experiments show that the robot can efficiently traverse sands and climb vertical railings. It has prominent adaptability to environment and obstacle-surmounting ability. The results prove the design of the mobile mechanism system to be rational.