中文摘要：

传统以刚体动力学为基础的四足机器人运动控制方法对地形误差敏感,无法适应粗糙复杂地形,因此提出一种基于虚拟模型的运动控制方法用于实现四足机器人在粗糙地形下的行走.建立了以足底接触力为约束的高层步行任务和底层运动控制的映射关系.采用弹簧-阻尼-质量虚拟模型对四足机器人进行建模,将四足机器人的步行任务用一系列作用于机体质心的虚拟力去表征,基于各足等效力矩平衡的原则,将笛卡儿空间的虚拟力矢量分配到各支撑足,利用雅可比矩阵把足端力矢量转换为机器人关节空间的关节转矩.针对崎岖的空间3维粗糙地形,建立了机器人躯干姿态与地形的关联参数,通过调整躯干姿态有效扩大了机器人对粗糙地形的适应程度.运动仿真结果表明,机器人可以实现粗糙地形下稳定连续的行走,足底接触力平稳、无冲击,证明了该柔顺步态生成方法的合理性和有效性.

英文摘要：

The conventional dynamic-based motion control for quadruped robots is sensitive to terrain errors and has difficulty in adapting to rough terrains. For this problem, a virtual model based motion control method is proposed for a quadruped robot walking on rough terrains. The mapping relationship between the high level locomotion task and low level motion control is built to satisfy the constraints of feet contact forces. The quadruped robot is built as a spring-damper-mass model. The locomotion task of the quadruped robot is represented using virtual forces acting on the mass centre of the body. A principle that all feet of the quadruped robot have balanced equivalent torques is assumed, based on which the virtual force vectors solved in Cartesian space are distributed to all supporting feet. The Jacobian matrix for each single leg is employed to convert the feet forces in Cartesian space into joint torques in joint space. As for rough terrains with 3D slopes, the trunk posture of the quadruped robot is changed according to the current terrain parameter so as to improve the robot＇s ability to adapt to highly-rough terrains. Dynamic simulations results show that the quadruped robot traverses the rough terrains successfully with small trunk undulations and steady ground forces on the feet. Therefore, the effectiveness of the presented compliant gait generation approach is proved.