School of Electrical Engineering and Computer Science, University of Ottawa, 800 King Edward, Ottawa, ON K1N 6N5, Canada.
Sensors (Basel). 2017 Jun 14;17(6):1384. doi: 10.3390/s17061384.
Compliance has been exploited in various forms in robotic systems to allow rigid mechanisms to come into contact with fragile objects, or with complex shapes that cannot be accurately modeled. Force feedback control has been the classical approach for providing compliance in robotic systems. However, by integrating other forms of instrumentation with compliance into a single device, it is possible to extend close monitoring of nearby objects before and after contact occurs. As a result, safer and smoother robot control can be achieved both while approaching and while touching surfaces. This paper presents the design and extensive experimental evaluation of a versatile, lightweight, and low-cost instrumented compliant wrist mechanism which can be mounted on any rigid robotic manipulator in order to introduce a layer of compliance while providing the controller with extra sensing signals during close interaction with an object's surface. Arrays of embedded range sensors provide real-time measurements on the position and orientation of surfaces, either located in proximity or in contact with the robot's end-effector, which permits close guidance of its operation. Calibration procedures are formulated to overcome inter-sensor variability and achieve the highest available resolution. A versatile solution is created by embedding all signal processing, while wireless transmission connects the device to any industrial robot's controller to support path control. Experimental work demonstrates the device's physical compliance as well as the stability and accuracy of the device outputs. Primary applications of the proposed instrumented compliant wrist include smooth surface following in manufacturing, inspection, and safe human-robot interaction.
顺应性已在机器人系统中以各种形式得到利用，以使刚性机构能够与易碎物体接触，或者与无法准确建模的复杂形状接触。力反馈控制一直是为机器人系统提供顺应性的经典方法。然而，通过将其他形式的仪器仪表与顺应性集成到单个设备中，可以在接触前后对附近物体进行更密切的监测。因此，可以在接近和接触表面时实现更安全、更平滑的机器人控制。本文介绍了一种通用、轻巧、低成本的仪器化顺应手腕机构的设计和广泛的实验评估，该机构可以安装在任何刚性机器人操纵器上，以便在与物体表面进行近距离交互时引入一层顺应性，同时为控制器提供额外的传感信号。嵌入式距离传感器阵列提供位于机器人末端执行器附近或与之接触的表面的位置和方向的实时测量，从而可以对其操作进行近距离引导。制定了校准程序以克服传感器之间的差异并实现可用的最高分辨率。通过嵌入所有信号处理来创建通用解决方案，而无线传输将设备连接到任何工业机器人的控制器，以支持路径控制。实验工作证明了该设备的物理顺应性以及设备输出的稳定性和准确性。所提出的仪器化顺应手腕的主要应用包括在制造、检查和安全人机交互中的平滑表面跟随。
