Industrial robotic applications such as spraying, welding, and additive manufacturing frequently require fast, accurate, and uniform motion along a 3D spatial curve. To increase process throughput, some manufacturers propose a dual-robot setup to overcome the speed limitation of a single robot. Industrial robot motion is programmed through waypoints connected by motion primitives (Cartesian linear and circular paths and linear joint paths at constant Cartesian speed). The actual robot motion is affected by the blending between these motion primitives and the pose of the robot (an outstretched/close to singularity pose tends to have larger path-tracking errors). Choosing the waypoints and the speed along each motion segment to achieve the performance requirement is challenging. At present, there is no automated solution, and laborious manual tuning by robot experts is needed to approach the desired performance. In this paper, we present a systematic three-step approach to designing and programming a dual-robot system to optimize system performance. The first step is to select the relative placement between the two robots based on the specified relative motion path. The second step is to select the relative waypoints and the motion primitives. The final step is to update the waypoints iteratively based on the actual relative motion. Waypoint iteration is first executed in simulation and then completed using the actual robots. For performance measures, we use the mean path speed subject to the relative position and orientation constraints and the path speed uniformity constraint. We have demonstrated the effectiveness of this method with ABB and FANUC robots on two challenging test curves. The performance improvement over the current industrial practice baseline is over 300%. Compared to the optimized single-arm case that we have previously reported, the improvement is over 14%.

翻译：工业机器人应用（如喷涂、焊接和增材制造）通常需要沿三维空间曲线实现快速、准确且均匀的运动。为提高工艺吞吐量，部分制造商提出采用双机器人配置来突破单台机器人的速度限制。工业机器人运动通过路径点及运动基元（恒定笛卡尔速度下的笛卡尔直线路径、圆弧路径和直线关节路径）进行编程。实际机器人运动会受到这些运动基元间的过渡融合以及机器人位姿（如手臂完全伸展或接近奇异位姿时会产生更大的路径跟踪误差）的影响。如何选择路径点及各运动段的速度以满足性能要求极具挑战性。目前尚无自动化解决方案，仍需机器人专家通过繁琐的手动调试来逼近期望性能。本文提出了一种系统性的三步法来设计和编程双机器人系统以优化系统性能：第一步，基于指定的相对运动路径选择两台机器人间的相对布置；第二步，选择相对路径点及运动基元；最后一步，根据实际相对运动迭代更新路径点。路径点迭代先在仿真环境中执行，再在实际机器人上完成。在性能指标方面，我们采用受相对位置与姿态约束及路径速度均匀性约束的平均路径速度作为衡量标准。我们使用ABB和FANUC机器人对两条具有挑战性的测试曲线验证了该方法的有效性。与现行工业实践基线相比，性能提升超过300%。与我们此前报道的优化单臂方案相比，性能提升超过14%。