Tool-Center-Point control of the KAI manipulator using constrained QP optimization

The KAI manipulator is a four joint mobile manipulator, which will be used within the German road clearance package to investigate improvised explosive devices and ordnance from within an armored vehicle. To improve handling of the manipulator, a Tool-Center-Point (TCP) control is implemented. By using constrained quadratic optimization (cQP) it is possible to allow for the control of the manipulator within three different operating spaces. The QP is formulated to account for constraints in the joint angular rates and TCP velocities, as well as additional velocity constraints, e.g. on the movement of the center of mass of the manipulator. The proposed algorithm is able to handle redundant as well as non redundant manipulator kinematics. By using an efficient QP solver the algorithm can be used within a real-time trajectory generation scheme. The performance of the algorithm is demonstrated using simulation results and validated by measurements of the TCP control.     

基于改进人工蜂群算法的冗余机器臂逆解研究

针对具有移动关节的7自由度机械臂逆运动学求解困难的问题,提出了一种基于改进人工蜂群算法的逆运动学求解方法。首先根据冗余机械臂的物理结构简化出几何模型,利用D-H法建立运动学模型,由坐标系变换得到正运动学的解。由于该冗余机械臂不满足Pieper准则,难以用传统方法求得封闭解;因此采用改进人工蜂群智能算法,利用位置误差与姿态误差的标准差作为目标函数,求取逆运动学的最优解,并利用Matlab编程进行仿真验证,仿真结果表明该方法准确有效,为具有移动关节的冗余机械臂逆运动学的求解提供了一种新的途径。     

码垛机器人运动学分析及关节空间轨迹规划研究

以IRB-460工业机器人为研究对象,针对其运动学建模及在笛卡尔空间和关节空间下的轨迹规划方法展开研究并进行对比。对机器人本体进行了机器人运动学分析,利用多项式轨迹插值算法进行了关键点间的轨迹规划,完成了重叠型码垛的作业流程。利用Robotics Toolbox完成了轨迹规划算法仿真,并进行了结果分析。仿真结果表明在关节空间下进行轨迹插补所得的路径点更为优化,所得的轨迹更为满足作业任务,具备合理性。     

基于ADAMS和MATLAB的双足机器人运动轨迹规划和控制的联合仿真

相比ADAMS仿真的不稳定性,利用ADAMS和MATLAB联合仿真对双足机器人运动轨迹规划和控制设计的可靠性及高效性进行了研究。首先绘制双足机器人三维参数模型进行逆运动学分析,验证其合理性后导入ADAMS中添加约束,进行动力学仿真。基于此,在MATLAB中使用多项式插值法完成模型的步态规划。最后利用Simulink试验台建立控制系统的框图,由ADAMS输入关节角之后控制台输出关节的驱动力矩,完成双足机器人ADAMS和MATLAB的联合仿真。仿真结果显示,联合仿真相较于ADAMS仿真的波动性所获得的数据更加稳定,此法高效可行,可作为下一步设计双足机器人的控制系统电机选型的重要理论依据。     

Piecewise constant strain kinematic model of externally loaded concentric tube robots

This paper presents a piecewise constant strain kinematic model for concentric tube robots (CTR) in externally loaded conditions. It discretizes the pre-curved tubes comprising the robot into a finite number of pieces and involves external effects as a set of wrench vectors exerted along the robot backbone. Constant strain lets us describe the pieces with helices in which shear deformation and elongation are neglected. The resulting piecewise helix is the simplest curve that can catch the torsion of tubes that play a crucial role in kinematic behavior. This approximation transforms the conventional boundary value problem (BVP) of CTRs models into a set of nonlinear equations that drastically decreases the model resolution time. The present method uses a Lyapunov function and torsional Jacobian to ensure the distal torsion constraint consistently and, as a result, the solution’s convergence. The paper’s primary purpose is to present a fast, numerically stable, and relatively accurate kinematic model not reliant on measurement data. Experimental results on a two-tube prototype and provided for different tip loading conditions reveal maintaining a balance between adequate accuracy and reasonable running time, about 7 ms for five pieces per section, for real-time applications in the presence of external load.     

新型激光切割并联机床的运动学研究及仿真

介绍了新型激光切割并联机床并联机构的构型和自由度分析,推导了运动学正逆解及雅各比矩阵,并基于雅各比矩阵进行了机构的速度特性分析。最后通过运动学仿真,模拟机床的加工过程,对运动学性能进行了验证,保证了设计的可靠性,为新型激光切割并联机床提供了设计和控制的理论依据。     

振动输送机运动学参数的半解析半数值方法

针对已往计算振动输送机运动学参数较繁杂的数值计算和解析方法,振动输送机机体振动是以简谐直线振动为主的,分析了双简谐振动槽面上的抛掷运动,对抛始角及抛止角进行了数值分析计算,给出了双简谐振动输送机理论平均输送速度的半解析半数值的简易计算方法,从而求出有关运动学参数,为设计该类振动形式的输送机提供了有效的简易计算方法。     

轴向柱塞泵中柱塞相对缸体的运动学分析

主要对轴向柱塞泵中的柱塞相对缸体运动进行了分析,得到了柱塞相对柱塞孔作往复运动的行程、速度和加速度的计算公式,为高速高压轴向柱塞泵的设计提供了一定的理论依据。     

基于空间六自由度机械臂的逆运动学数值解法

针对解析法只能用于特殊构型的机械臂且求解过程复杂、计算量大的问题,提出一种适用于大多数串联型机械臂的数值迭代逆运动学求解方法.利用该方法,求解自主研发的空间六自由度机械臂的运动学逆解,并通过仿真证明该方法的可靠性.     

基于CANopen的八轮AGV运动控制及里程计算法在智能制造中的应用

在智能制造中,重载自动导引车(AGV)应用较广,但是大多数灵活性较低。设计了由8个麦克纳姆轮+直流伺服电机+直流伺服驱动器及减速机构成的全向AGV。八轮称重能力强,解决了称重问题,同时由于麦克纳姆轮的特性,移动更灵活。采用CANopen进行伺服驱动器控制和信息采集。通过对麦克纳姆轮运动学进行解算,得到每个轮子的速度,实现了AGV的高精度控制。