Sampling-based model-predictive control (MPC) is a promising tool for feedback control of robots with complex, non-smooth dynamics, and cost functions. However, the computationally demanding nature of sampling-based MPC algorithms has been a key bottleneck in their application to high-dimensional robotic manipulation problems in the real world. Previous methods have addressed this issue by running MPC in the task space while relying on a low-level operational space controller for joint control. However, by not using the joint space of the robot in the MPC formulation, existing methods cannot directly account for non-task space related constraints such as avoiding joint limits, singular configurations, and link collisions. In this paper, we develop a system for fast, joint space sampling-based MPC for manipulators that is efficiently parallelized using GPUs. Our approach can handle task and joint space constraints while taking less than 8ms~(125Hz) to compute the next control command. Further, our method can tightly integrate perception into the control problem by utilizing learned cost functions from raw sensor data. We validate our approach by deploying it on a Franka Panda robot for a variety of dynamic manipulation tasks. We study the effect of different cost formulations and MPC parameters on the synthesized behavior and provide key insights that pave the way for the application of sampling-based MPC for manipulators in a principled manner. We also provide highly optimized, open-source code to be used by the wider robot learning and control community. Videos of experiments can be found at: https://sites.google.com/view/manipulation-mpc
翻译:以抽样为基础的模型预测控制(MPC)是一个很有希望的工具,用于对具有复杂、非光滑动态和成本功能的机器人进行反馈控制。然而,基于取样的MPC算法在计算上要求很高的性质一直是对现实世界中高维机器人操纵问题应用的关键瓶颈。以前的方法在任务空间运行MPC,同时依靠一个低级别的操作空间控制器来进行联合控制,从而解决这个问题。然而,由于在MPC的配制中不使用机器人的联合空间空间,现有方法无法直接说明与非任务空间有关的制约因素,如避免联合限制、奇数和连接碰撞等。在本文件中,我们开发了一个快速、联合基于空间采样的MPC系统,用于在使用GPUPs进行高效平行的操控器。我们的方法可以处理任务和联合空间限制,同时使用不到8mus~(125Hz)来计算下一个控制命令。此外,我们的方法可以通过利用从原始传感器数据中学习的成本功能,将视野与控制问题紧密地纳入控制问题之中。我们通过将自己的方法加以验证,我们将其用于使用高额操作的系统模拟操作,我们用在弗兰克-Pandaroducal roduma roupal roupal rodulema rodu可以提供一种不同的成本分析方法。