The hydraulic joint is the key driving component of a robot. To reduce the joint size of the hydraulic robot, and improve the control accuracy and dynamic response performance, this paper proposes a novel joint structure and control method of a ball double-screw hydraulic robot. Using ball and circular arc spiral groove transmission, the hydraulic joint has a small transmission friction coefficient, compact overall structure and higher transmission accuracy. Aiming to resolve the problems of low control accuracy and motion instability caused by temperature drift in valve-controlled hydraulic systems, the high-precision joint control method based on adaptive fuzzy control compensation is used to improve the control accuracy and stability. The static and dynamic characteristics of the designed hydraulic joint are analyzed by simulation. A test platform was built, and the physical prototype of the hydraulic joint underwent static testing, dynamic control, amplitude frequency response and trajectory tracking tests. The experimental results were similar to the simulation results. The ball double-screw hydraulic robot joint has the characteristics of low starting pressure, high energy density, fast dynamic response, small amplitude frequency attenuation and high control accuracy. The starting pressure is 0.5 MPa, maximum swing frequency is 3 Hz, positioning accuracy is ± 0.03°, tracking accuracy is ± 3.9° and maximum angular velocity at 10 MPa is about 7.6 rad/s, which is close to the angular velocity of the actual human joint.

液压关节是机器人的关键驱动部件。为减小液压机器人的关节尺寸，提高控制精度和动态响应性能，提出一种新型滚珠双螺杆液压机器人关节结构及控制方法。该液压接头采用滚珠和圆弧螺旋槽传动，传动摩擦系数小，整体结构紧凑，传动精度更高。针对阀控液压系统因温度漂移引起的控制精度低和运动不稳定等问题，采用基于自适应模糊控制补偿的高精度联合控制方法，提高控制精度和稳定性。对所设计的液压接头的静态和动态特性进行了仿真分析。搭建了试验平台，对液压接头实物样机进行了静态试验、动态控制、幅频响应和轨迹跟踪试验。实验结果与模拟结果相似。滚珠双螺杆液压机器人关节具有启动压力低、能量密度高、动态响应快、幅频衰减小、控制精度高等特点。启动压力为0.5 MPa，最大摆频为3 Hz，定位精度为±0.03°，跟踪精度为±3.9°，10 MPa时最大角速度约为7.6 rad/s，接近角速度实际的人体关节。幅频响应和轨迹跟踪测试。实验结果与模拟结果相似。滚珠双螺杆液压机器人关节具有启动压力低、能量密度高、动态响应快、幅频衰减小、控制精度高等特点。启动压力为0.5 MPa，最大摆频为3 Hz，定位精度为±0.03°，跟踪精度为±3.9°，10 MPa时最大角速度约为7.6 rad/s，接近角速度实际的人体关节。幅频响应和轨迹跟踪测试。实验结果与模拟结果相似。滚珠双螺杆液压机器人关节具有启动压力低、能量密度高、动态响应快、幅频衰减小、控制精度高等特点。启动压力为0.5 MPa，最大摆频为3 Hz，定位精度为±0.03°，跟踪精度为±3.9°，10 MPa时最大角速度约为7.6 rad/s，接近角速度实际的人体关节。