Regional optimal coverage control of multi-manipulator systems
-
摘要:
针对具有强非线性特点的机械臂覆盖控制问题,基于Voronoi图理论,提出了一种多机械臂系统的区域最优覆盖控制算法. 首先,通过计算各个机械臂末端执行器的位置,将目标区域进行Voronoi划分;其次,根据凸优化理论,通过定义的描述区域覆盖控制效果的目标代价函数来衡量多机械臂系统关节以及末端执行器的移动是否最优;最后,结合机械臂系统特殊的动力学特性,给出了多机械臂系统的分布式区域最优覆盖控制器. 利用Lyapunov稳定性理论对该算法进行了稳定性分析,数值仿真实验表明了算法的实际有效性,即所提算法可以使得多机械臂系统的末端执行器在代价函数值最小的情况下到达相应Voronoi区域质心并且速度渐近收敛到零,形成对目标区域的最优覆盖. 特别地,该算法以机械臂为研究对象,丰富了现有的覆盖控制智能体模型研究,此外基于机械臂的非线性结构特性,算法中所设计的任务空间覆盖控制律,还可以应用到二阶系统智能体的覆盖控制研究中,拓宽了现有的基于一阶系统的覆盖控制研究.
-
关键词:
- 多机械臂系统 /
- 覆盖控制 /
- Voronoi划分 /
- Euler-Lagrange系统
Abstract:Aiming at the coverage control problem of the manipulator with strong nonlinear characteristics, based on Voronoi diagram theory, a region optimal coverage control algorithm for multi-manipulator systems is proposed. Firstly, the target region is divided into Voronoi regions by calculating the position of the end effectors of each manipulator; Secondly, according to the convex optimization theory, the optimal movement of the joints and the end effectors of the multi-manipulator systems are measured by the defined objective cost function that describes the effect of area coverage control; Finally, combined with the special dynamic characteristics of the manipulator system, the distributed area optimal coverage controller of the multi-manipulator systems is given. The Lyapunov stability theory is used to analyze the stability of the algorithm. Numerical simulation experiments show that the algorithm is effective, that is, the proposed algorithm can make the end effectors of the multi-manipulator systems reach the corresponding Voronoi region centroids with the minimum cost function value, and the speed gradually converges to zero, forming the optimal coverage of the target region. In particular, the algorithm takes the manipulator as the research object, which enriches the existing research on the coverage control agent model. In addition, based on the nonlinear structural characteristics of the manipulator, the coverage control law of the task space designed in the algorithm can also be applied to the coverage control research of the second order system agent, expanding the existing coverage control research based on the first order system.
-
多机械臂系统最优覆盖控制算法总体框架 Input:多机械臂系统初始关节角$q=[q_{1}, \cdots, q_{n}]^{{\rm{T}}}$;末端执行器初始位置$P=[p_{1}, \cdots, p_{n}]^{{\rm{T}}}$;目标区域的敏感度函数$ \phi({e}) $;任务执行时间$ t $. Output:多机械臂系统的末端移动轨迹、末端位置变化、关节速度变化及多机械臂最优分布; 1. 初始化:机械臂的关节角速度$d q=\left[\dot{q}_1, \cdots, \dot{q}_n\right]^{\rm{T}}$,末端速度$d P=\left[\dot{p}_1, \dot{p}_2, \cdots, \dot{p}_n\right]^{\rm{T}}$,末端加速度$d d P=\left[\ddot{p}_1, \ddot{p}_2, \cdots, \ddot{p}_n\right]^{\rm{T}}$; 2. 根据当前每个机械臂末端执行器的位置对目标区域进行Voronoi划分,并获得每个Voronoi区域的质心和质量信息; 3. 计算末端执行器位置与相应区域质心的距离$d=[\|p_1-C_{V_1}\|, \cdots,\|p_n- C_{V_v}\|]^{\rm{T}}$; 4. 若$ d>0$或$ d P \neq 0$,进入步骤5; 若$ d=0$且$ d P=0$,进入步骤6; 5. 由控制器(10)计算机械臂的动力输入$\tau=\left[\tau_1, \tau_2, \cdots, \tau_n\right]^{\rm{T}}$,得到下一时刻的机械臂的关节角位移$q=\left[q_1, \cdots, q_n\right]^{\rm{T}}$、关节角速度$d q=\left[\dot{q}_1, \cdots, \dot{q}_n\right]^{\rm{T }}$、多机械臂系统末端的位置$P=[p_1, \cdots, p_n]^{\rm{T}}$和速度${d P}=\left[\dot{p}_1, \dot{p}_2, \cdots, \dot{p}_n\right]^{\rm{T}}$,重复步骤2到4, 6. 算法执行时间结束,多机械臂系统实现了对目标区域的最优覆盖. 表 1 多机械臂系统初始参数设定
Table 1. Initial parameter setting of multi-manipulator systems
初始参数 机械臂底端初始坐标 关节角$ q_{1} $ 关节角$ q_{2} $ 机械臂1 (0,0) $ \dfrac{1}{3} \pi $ $ -\dfrac{1}{6} \pi $ 机械臂2 (1,1) $ -\dfrac{2}{3} \pi $ $ -\dfrac{1}{6} \pi $ 机械臂3 (1,0) $ \dfrac{2}{3} \pi $ $ \dfrac{1}{3} \pi $ 机械臂4 (0,1) $ -\dfrac{1}{4} \pi $ $ \dfrac{1}{6} \pi $ -
[1] SHAMMA J S. Cooperative control of distributed multi-agent systems[M]. John Wiley & Sons, 2008. [2] LIU Z W, WENG H, YU X H, et al. Delayedimpulsive control for consensus of multiagent systems with switchingcommunication graphs[J]. IEEE Transactions on Cybernetics,2020,50(7):3045-3055. DOI: 10.1109/TCYB.2019.2926115. [3] XU J Z, GE M F, LIU Z W, et al. Force-reflecting hierarchical approach for human-aided teleoperation of NRS with event-triggered local communication[J]. IEEE Transactions on Industrial Electronics,2022,69(3):2843-2854. DOI: 10.1109/TIE.2021.3068678. [4] 王晓波, 邢建春, 李决龙, 等. 多智能体系统快速有限时间平均一致性协议研究[J]. 微电子学与计算机,2018,35(5):11-14. DOI: 10.19304/j.cnki.issn1000-7180.2018.05.003.WANG X B, XING J C, LI J L, et al. Finite-time average consensus protocol for multi-agent systems with a fast convergence rate[J]. Microelectronics & Computer,2018,35(5):11-14. DOI: 10.19304/j.cnki.issn1000-7180.2018.05.003. [5] 甄冒发, 徐振峰, 谢宇. 多自由度机器人惯性误差反馈融合闭环控制[J]. 微电子学与计算机,2020,37(12):77-80. DOI: 10.19304/j.cnki.issn1000-7180.2020.12.015.ZHEN M F, XU Z F, XIE Y. A closed-loop control method for inertial error feedback fusion of multi-degree-of-freedom robot[J]. Microelectronics & Computer,2020,37(12):77-80. DOI: 10.19304/j.cnki.issn1000-7180.2020.12.015. [6] XIAO H, CUI R X, XU D M. A sampling-based Bayesian approachfor cooperative multiagentonline search with resource constraints[J]. IEEE Transactions on Cybernetics,2018,48(6):1773-1785. DOI: 10.1109/TCYB.2017.2715228. [7] HU X, LIU Z W, WENG H, et al. Voltage control fordistribution networks via coordinated regulation of active and reactivepower of DGs[J]. IEEE Transactions on Smart Grid,2020,11(5):4017-4031. DOI: 10.1109/TSG.2020.2989828. [8] LI L L, ZHANG X Y, YU E W, et al. Cooperative search fordynamic targets by multiple UAVs with communication data losses[J]. ISA Transactions,2021,114:230-241. DOI: 10.1016/j.isatra.2020.12.055. [9] ZHENG X M, KOENIGS, KEMPED, e al. Multirobot forest coverage for weighted and unweighted terrain[J]. IEEE Transactions on Robotics,2010,26(6):1018-1031. DOI: 10.1109/TRO.2010.2072271. [10] HANAY Y S, GAZIV. Distributed sensor deployment usingpotential fields[J]. Ad Hoc Networks,2017,67:77-86. DOI: 10.1016/j.adhoc.2017.09.006. [11] YU D X, XU H, CHENCLP, et al. Dynamic coverage control based on K-means[J]. IEEE Transactions on Industrial Electronics,2022,69(5):5333-5341. DOI: 10.1109/TIE.2021.3080205. [12] CORTES J, MARTINEZ S, KARATAS T, et al. Coverage control for mobile sensing networks[J]. IEEE Transactions on Robotics and Automation,2004,20(2):243-255. DOI: 10.1109/TRA.2004.824698. [13] JIANG B M, SUN Z Y, ANDERSON B D O, et al. Higher order mobile coverage control with applications to clustering of discrete sets[J]. Automatica,2019,102:27-33. DOI: 10.1016/j.automatica.2018.12.028. [14] SUN Q H, CHI M, LIU Z W, et al. Observer-based coveragecontrol of unicycle mobile robot network in dynamic environment[J]. Journal of the Franklin Institute,2022. DOI: 10.1016/j.jfranklin.2022.06.050. [15] LIU T R, VELNI J M. Multi-agent systems coverage control in mixed-dimensionaland hybrid environments[J]. IFAC-PapersOnLine,2021,54(20):765-770. DOI: 10.1016/j.ifacol.2021.11.264. [16] ABDULGHAFOOR A, BAKOLAS E. Distributed coverage control of multi-agent networks with guaranteed collision avoidance in cluttered environments[J]. IFAC-PapersOnLine,2021,54(20):771-776. DOI: 10.1016/j.ifacol.2021.11.265. [17] KWOK A, MARTÌNEZ S. Unicyclecoverage control via hybrid modeling[J]. IEEE Transactionson Automatic Control,2010,55(2):528-532. DOI: 10.1109/TAC.2009.2037473. [18] CARRONA, ZEILINGERM N. Model predictive coveragecontrol[J]. IFAC-PapersOnLine,2020,53(2):6107-6112. DOI: 10.1016/j.ifacol.2020.12.1686. [19] CASSANDRAS C G, LI W. Sensor networks and cooperative control[J]. European Journal of Control,2005,11(4-5):436-463. DOI: 10.3166/ejc.11.436-463. [20] KRISHNAN V, MARTÍNEZS. A multiscale analysis of multi-agent coverage control algorithms[J]. Automatica,2022,145:110516. DOI: 10.1016/j.automatica.2022.110516. [21] HOWARD A, MATARIĆ M J, SUKHATME G S. Mobile sensor network deployment using potential fields: a distributed, scalable solution to the area coverage problem[M]//ASAMA H, ARAI T, FUKUDA T, et al. Distributed Autonomous Robotic Systems. Tokyo: Springer, 2002: 299-308. [22] ZHANG Y F, ZHU M, CHEN T, et al. Region coverage control for multiple stratospheric airships with combined self-/event-triggered mechanism[J]. Defence Technology,2022. DOI: 10.1016/j.dt.2022.04.002. [23] 邢萧飞. 无线传感器网络覆盖控制优化算法研究[D]. 长沙: 中南大学, 2012.XING X F. Optimization algorithms of coverage control for wireless sensor networks[D]. Changsha: Central South University, 2012. [24] ZHU C, ZHENG C L, SHU L, et al. A survey on coverage and connectivity issues in wireless sensor networks[J]. Journal of Network and Computer Applications,2012,35(2):619-632. DOI: 10.1016/j.jnca.2011.11.016. [25] 罗凯. 多智能体系统的动态覆盖控制研究[D]. 武汉: 华中科技大学, 2019.LUO K. Dynamic coverage control of multi-agent systems[D]. Wuhan: Huazhong University of Science & Technology, 2019. [26] SUN X M, CASSANDRAS C G, MENG X Y. Exploiting submodularity to quantify near-optimality in multi-agent coverage problems[J]. Automatica,2019,100:349-359. DOI: 10.1016/j.automatica.2018.11.020. [27] 张佳舒, 赵宁, 赵东亚. 基于神经网络的机械臂任务空间滑模同步控制[J]. 山东科技大学学报(自然科学版),2019,38(4):107-116. DOI: 10.16452/j.cnki.sdkjzk.2019.04.014.ZHANG J S, ZHAO N, ZHAO D Y. Sliding mode synchronous control for multiple robotic manipulator systems based on neural network[J]. Journal of Shandong University of Science and Technology(Natural Science),2019,38(4):107-116. DOI: 10.16452/j.cnki.sdkjzk.2019.04.014. [28] 左磊. 多智能体最优覆盖控制方法研究[D]. 西安: 西北工业大学, 2017.ZUO L. Coverage control for multi-agent systems[D]. Xi’an: Northwestern Polytechnical University, 2017. [29] BULLO F, CORTÉS J, MARTÍNEZ S. Distributed control of robotic networks: a mathematical approach to motion coordination algorithms[M]. Princeton: Princeton UniversityPress, 2009. -