RESEARCH ON REACTIONLESS MANIPULATOR

提出了一种通过惯性耦合进行反应补偿的通用方法。这种方法我们称之为“反应零空间法”。在我们早期的工作中，我们专注于移动基座系统，例如自由飞行的空间机器人和长距离机械手或柔性基座机械手。我们已经证明，通过反应零空间，机械手的动力学与基座的动力学是解耦的。例如，使用该符号，我们可以分析系统，以获得机械手工作空间中的所谓“无反作用力路径”。沿这些路径的任何运动都不会激发基础动力学。此外，反作用力零空间对于设计目的很有用。这一点从反作用零空间可能存在于不同类型的设计的事实中看得很清楚。在我们最新的工作中，我们扩展了反应零空间方法的范围，以涵盖整个类型的欠驱动机械手。除了动基式机器人，这一类还包括自由关节和柔性关节机器人和柔性-L…设计了一种由柔性基座和弹性悬臂梁组成的柔性基座机械手的平面实验系统。最初，在底座的顶端安装了一个小型2R刚性连杆机械手。在刚性连杆机械手的底座上安装了一个特殊设计的力/力矩传感器来测量平面内的反力。通过应变片获得弹性基础挠度的控制反馈。通过这种设计，我们可以获得单臂情况下的有用的实验数据，这证实了我们对无反作用力运动的期望。后来，我们在系统上安装了第二个刚性连杆机械手。首先，验证了开环控制和闭环控制下无反应路径跟踪的可行性，在这两种情况下，底座的扰动都是可以忽略的。当沿无反作用力路径的加速度和速度改变时，这种情况不会改变。这与理论完全一致。我们注意到，对于拿着物体的双臂机械手来说，也存在无反作用力的路径。这一点在实验上得到了验证。其次，提出了一种单臂三阶段路径规划方法。实验表现证实了我们的预期。我们将结果与著名的扰动映射法进行了比较。最后，采用主动阻尼法实现了减振控制。我们已经证明了振动抑制与无反作用力路径运动是解耦的。这意味着两个控制子任务的反馈增益可以独立设计。可以在沿着无反作用力的路径移动时抑制振动。我们还证实了双臂机械手握住物体进行振动抑制的可能性。较少

We developed a general method for reaction compensation via inertial coupling. This method we called "reaction null space" method. In our early work we focused on moving base systems, such as free-flying space robots and long-reach manipulators or flexible base manipulators. We have shown that via the reaction null space, the dynamics of the manipulator are decoupled from the dynamics of the base. Using the notation, we can analyze the system, for example, to obtain the so-called "reactionless paths" in the workspace of the manipulator. Any motion along these paths will not excite the base dynamics.Also, the reaction null space is useful for design purposes. This is clear from the fact that the reaction null space may exist with different types of design. In our latest work we extend the scope of the reaction null space method to cover the whole class of underactuated manipulators. In addition to moving base robots, this class includes also free-and flexible-joint robots and flexible-l … More ink robots.We designed a planar experimental system of a flexible-base manipulator comprising a flexible base with an elastic cantilever beam. Initially, a small 2R rigid link manipulator was mounted on the tip of the base. A force/torque sensor with a special design was mounted on the base of the rigid link manipulator to measure reactions in the plane. Control feedback from elastic base deflection was obtained through a strain gauge. With this design we could obtain useful experimental data for the one-arm case, which confirmed our expectation regarding reactionless motion. Later, we attached a second rigid-link manipulator to the system. With this experimental setup we could perform noncontact motion experiments, as follows.First, feasibility of reactionless path tracking was confirmed both under open loop and closed-loop control.In either case, the disturbance of the base was ignorable. This situation didn't change when the acceleration and the speed along the reactionless path were changed. This is well in agreement with theory. We note that the reactionless paths do exist also for a dual-arm manipulator holding an object. This was verified experimentally. Second, we developed a three-phase path planning method for a single arm. The experimental performance confirmed our expectations. We compared the results with the well-known method of Disturbance Map. Finally, we implemented vibration suppression control by active damping. We have shown that vibration suppression is decoupled from the reactionless path motion. This means that feedback gains of the two control subtasks can be designed independently. It is possible to suppress vibrations while moving along a reactionless path. We have also confirmed the possibility of vibration suppression with a dual-arm manipulator holding an object. Less