Algorithmization of Constrained Motion for Car-Like Robots Using the VFO Control Strategy with Parallelized Planning of Admissible Funnels
Algorithmization of Constrained Motion for Car-Like Robots Using the VFO Control Strategy with Parallelized Planning of Admissible Funnels
复制标题
使用 VFO 控制策略和可接受漏斗并行规划的类车机器人约束运动算法
DOI：
10.1109/iros.2018.8594402
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
M. Michałek
中科院分区：
文献类型：
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作者：
Tomasz Gawron;M. Michałek
具有类似汽车运动学的车辆是普遍存在的，因此算法化的能力（即，如何计划和有效地执行）在障碍物存在下的复杂机动对于移动的机器人和智能车辆是至关重要的。传统上，这个问题是解决使用众所周知的运动规划算法，它产生的开环控制信号忽略了测量噪声，建模的不确定性和不完善的机器人驱动的影响。虽然这种影响可以在一定程度上补偿在线重新规划，反馈控制算法的运动执行的应用是不可避免的，如果系统的鲁棒性是期望的。因此，最近的工作集中在运动规划和控制算法的集成，以获得运动规划鲁棒的初始条件的不确定性。根据这一趋势，我们提出了一个修改的VFO（矢量场定向）控制律，它的目的是满足的状态和输入的限制所产生的障碍物的存在下，在环境中，尊重转向角的限制与转向动力学的车一样的机器人，并保持控制输入信号的连续性。由于分析特性的容许漏斗（即积极不变的配置空间的子集）开发的VFO控制法的分析，我们保证满足所有提到的约束在连续域的时间和配置空间的机器人，而不牺牲计算效率的规划过程。一个特定的漏斗计划与高度并行化的确定性采样为基础的算法实现准实时性能。
Vehicles with car-like kinematics are ubiquitous, therefore an ability to algorithmize (i.e., how to plan and effectively execute) complex maneuvers in the presence of obstacles is vital to mobile robotics and intelligent vehicles. Traditionally, this problem is solved using the well known motion planning algorithms, which generate the open-loop control signals neglecting the effects of measurement noises, modeling uncertainties and imperfect robot actuation. While such effects can be compensated to some extent by online replanning, the application of feedback control algorithms to motion execution is unavoidable if robustness of the system is desired. Consequently, the recent works focus on integration of both motion planning and control algorithms to obtain motion plans robust to uncertainty of the initial conditions. In accordance with this trend, we propose a modified VFO (Vector Field Orientation) control law, which is designed to satisfy the state and input constraints resulting from the presence of obstacles in the environment, respect the steering angle limits in conjunction with steering dynamics of the car-like robot, and preserve continuity of the control input signals. Thanks to analytic characterization of admissible funnels (i.e. positively invariant subsets of the configuration space) developed from an analysis of the VFO control law, we guarantee satisfaction of all the mentioned constraints in the continuous domains of time and configuration space of the robot without sacrificing computational efficiency of the planning process. A specific funnel is planned with a highly parallelized deterministic sampling-based algorithm achieving quasi-real-time performance.