Real-time and efficient path planning is critical for all robotic systems. In particular, it is of greater importance for industrial robots since the overall planning and execution time directly impact the cycle time and automation economics in production lines. While the problem may not be complex in static environments, classical approaches are inefficient in high-dimensional environments in terms of planning time and optimality. Collision checking poses another challenge in obtaining a real-time solution for path planning in complex environments. To address these issues, we propose an end-to-end learning-based framework viz., Path Planning and Collision checking Network (PPCNet). The PPCNet generates the path by computing waypoints sequentially using two networks: the first network generates a waypoint, and the second one determines whether the waypoint is on a collision-free segment of the path. The end-to-end training process is based on imitation learning that uses data aggregation from the experience of an expert planner to train the two networks, simultaneously. We utilize two approaches for training a network that efficiently approximates the exact geometrical collision checking function. Finally, the PPCNet is evaluated in two different simulation environments and a practical implementation on a robotic arm for a bin-picking application. Compared to the state-of-the-art path planning methods, our results show significant improvement in performance by greatly reducing the planning time with comparable success rates and path lengths.
翻译:实时高效的路径规划对于所有机器人系统都至关重要。特别是对于工业机器人来说,由于规划和执行时间直接影响生产线的周期时间和自动化经济性,因此整体时间表越小越好。虽然在静态环境中这个问题可能并不复杂,但是在高维环境中经典方法在规划时间和最优性方面效率低下。在复杂环境中,碰撞检测构成了获得路径的实时解决方案的另一个挑战。为了解决这些问题,我们提出了一种综合学习框架,即路径规划和碰撞检测网络(PPCNet)。通过连续计算路点,PPCNet生成路径,其中使用了两个网络:第一个网络生成一个路点,第二个网络确定该路点是否在路径的无碰撞线段上。基于模仿学习的端到端训练过程使用了来自专家规划员经验的数据聚合来训练这两个网络。我们利用两种方法来训练网络,以有效近似确切的几何碰撞检测函数。最后,我们基于PPCNet在两种不同的仿真环境下进行评估,并在抓取应用的机械臂实现了实际应用。与现有的路径规划方法相比,我们的结果显示,在可比较的成功率和路径长度方面,规划时间大大缩短了,大大提高了性能。