足地接触冲击对大尺度重载足式机器人的运动性能影响显著。针对液压驱动六足机器人，以低冲击平顺运动为目标，提出一种减小足地接触冲击的足端轨迹规划方法。基于仿生构型和运动学模型推导腿部关节的角度函数，根据液压缸铰点布置和腿部机构几何关系推导出各液压缸活塞杆的位置控制函数，分析表明关节和液压缸运动平稳，速度、加速度无突变。基于Vortex搭建机器人仿真平台，采用该方法实现了步行过程的仿真模拟，机体稳定前移过程中的垂向起伏微小，侧向偏移率约为2.1%。将该方法应用于开发的六足机器人原理样机，进行野外自然环境行走测试，各关节按预定轨迹平稳运动，足端受力合理。仿真结果与试验结果具有较好的一致性，验证了提出的运动规划方法合理可行。

Foot-terrain contact impact has a significant effect on the movement performance of large-scale heavy legged robot. A low-impact motion planning method of foot trajectory for hydraulically actuated hexapod robot with the goal of smooth movement is proposed. Angle functions of each joint are deduced based on the bionic configuration and kinematics model, and position control functions of hydraulic cylinder piston rod are solved according to the arrangement of hydraulic cylinder hinged points and the geometric relationship of leg. Analysis results indicate that joints and hydraulic cylinders move steady and their velocity and acceleration are continuous. Simulation platform is established based on Vortex, and simulation of walking process by using the proposed method is completed. The vertical fluctuation of body is tiny in the process of stable moving forward, and the lateral migration rates are about 2.1%. This method is applied to the field experiments of hexapod robot prototype. Test results conclude that the joints move smoothly following the desired trajectory, and the foot force is reasonable. The simulation results and experimental results are consistent, and the rationality and feasibility of the foot trajectory planning method is verified.