Mentioned dynamics, our first impression is often the formula a few lines or even a few hundred lines, most of the kinetic interested friends may thus stalled, in fact, pure vivid and rich formula than the dynamics of many. For readers of intuitive controller dynamics and comprehensive understanding of the author only schematically summarizes the dynamics including definitions, applications, modeling, deployment and specific evaluation criteria, including aspects.
Dynamics defined
Dynamics (Dynamics) is applied to the study of the general relationship between object motion and force of the object, particularly to an industrial robot, comprising two fundamental issues:
1) the known effects of the force of each joint of the robot, the joint corresponding to seek trajectory, i.e. find the acceleration, velocity and position;
2) It is known that the current robot joint acceleration, velocity and position, the size of the force required at this time the joint.
Simply speaking, the relationship between the kinetic force is resolved and the size of each joint of the robot by moving it, known characteristics of movement corresponding to the magnitude of the force can be obtained, whereas, the magnitude of the force is known, movements of the robot can be calculated characteristic.
Dynamic model / equation
There are many ways of calculating the kinetics, such LAGRANGE , the Newton-the Euler, GAUSS, Kane, Screw, Roberson-from Wittenburg. Among them, Lagrange, Newton-Euler most commonly used. In fact dynamic model of these methods can be transformed into each other eventually. We two link robot movement in a vertical plane, for example, to observe the general dynamics model by which items composition, on a visual understanding of the kinetics. Two link robot dynamic model of the observed motion in a vertical plane can be found, using Lagrangian dynamics model established method, the final form can be represented by the following criteria.
Standard pure kinetic model if expressed in the form of a force, i.e. the force which is inertia, centrifugal force, Coriolis force (also known as the Coriolis force), viscous friction, static friction, gravity, external force (e.g., manual application or contact with the environment), consisting of a series of equations joint torque. It should be noted here is friction model: + viscous friction Coulomb friction, the friction of different models, the above equations only differ in the friction at the remainder unchanged.
In addition to the Coriolis force, several other forces are relatively easy to understand. So what Coriolis force performance in our lives is? Careful readers may find in life, inconsistencies on both sides of the river were scouring the river. Another is called "one of the most beautiful experiments in physics," the Foucault pendulum, is also affected by the Coriolis force. The nature of the cause of the Coriolis force on Earth's rotation rate is in different places in different dimensions, but for a robot, its different joints different speed, it will also cause Coriolis phenomenon.
Attachment: Foucault Pendulum
Swing on Earth will be affected by the earth's rotation. As long as there is a certain angle between the direction of the angular velocity of the pendulum plane direction of rotation of the earth, it would be placed face Coriolis effect, generating a direction opposite to the Earth's rotation torque, so that the pendulum plane rotating occurs. 1851 French physicist Foucault predicted the existence of this phenomenon, and to experiment show that this phenomenon, he composed a pendulum with a length of 67 meters of rope and a 27 kg of metal balls, hanging in the balance inlaid with a pointer to this huge pendulum suspended above the church dome, experiments confirmed the swing plane in the northern hemisphere will slowly rotate to the right.
Deployment dynamics controller
Dynamic model-based controller, specific implementation of the system configuration depending vary. A controller for actuating one of the architecture, we can use the control mode "Computed Torque (compute torque)"; and to the system bus for a distributed control structure, by the (?? Forward, reverse) to calculate the kinetic the moment feed forward manner, the current is added to the servo control loop, to complete the design of the controller kinetics, dynamics controller below the front of the torque feed forward manner. It should be noted that, for those who do not support the servo feed-forward torque, dynamics controller can be implemented by means of feed-even position feedforward before speed.
way to control
sport control
Robot task: to perform specific movements and contact forces in the workspace.
Motion control purposes: generalized force determined by the articulation formed by the actuator, while achieving the task to ensure that, to meet the transient and steady state given requirements.
Two control schemes: the joint space and the control space control operations. Solutions to control the joint space by inverse kinematics motion of each joint is calculated, and then the real motion to track reference input. Exams control operation method for finding using spatial, more complex calculation, and the position and orientation of the end of the operation is difficult to be measured directly.
Force control
前提：机械手与外部环境有交互力。在交互作用中，环境会对末端执行器的路径产生约束。 背景：在任务准确规划的前提下，才能通过运动控制实现与环境的交互任务。这需要机械手（运动学和动力学）和环境（几何特征、机械特性）的准确建模。对环境建模十分困难。 在力控制中，如果关节没有柔性，可能破坏机械臂执行元件或与机械手接触的环境。
阻抗控制：建立一个期望的机器人位置和接触力的动态响应关系。将外界环境系统视为对机器人系统的一种“干扰”，并给机器人在受外界力而偏离既定运动时具有阻抗形式的扰动响应。通过改变上述阻抗，就可以调节机器人与外界的动态作用。
