Researching The Kinematics And Dynamics Of The Rigid Body System With Non-Fixed Point Collision

The rigid body system dynamic problem with the friction or collision which is non-smooth constraint has an important engineering background, and it is still a hotspot and difficulty in this field researching. Especially when the collision point of the rigid body system varies with the time, how to accurately determine the collision point position and give the effective numerical simulation method for the kinematics and dynamics are the key point to solve the rigid body system collision problem.In this paper, by the premise of keeping rigidity, for some rigid system which has special shape, such as rod shape,rectangular plate and so on, when they motion, the potential contact points and the minimum distance of them can be solved for the characteristic of the geometric body, according to this feature, we can avoid to enter the complex iterative searching process, thereby, we realize the practical and simple numerical simulation of the kinematics and dynamics for the kind of the rigid body system motion process with the contact-impact. The main contents of this paper as follows:For the same initial conditions, we have numerical simulation of the kinematics and dynamics with the multi-non-fixed point collision process which is the homogeneous rigid rod,circular plate and rectangular plate contact to the ground, from analyzing and comparing the results, we can obtain the follow conclusion:the reason of the rigid body has the different contact-impact model is it has the different shape, they have the same initial conditions, but the corresponding collision dynamic response has the more obvious differences, so this verifies the geometry researching of the rigid body system has an significance in revealing the collision motion law of the rigid body system.Researching the general collision problem of the planar manipulator system, the uncertainty of the system's collision point subjoining the difficulty in treating the collision identify and calculating the collision impulse. According to the geometric characteristics of the manipulator system, obtaining the relatively simple method of the testing when and where the contact-impact happens in the motion process, establishing the kinetic equation which in the non-collision stage and the kinetic equation which in the collision stage by the Lagrange method, so the general framework of the manipulator system motion process with the collision has a complete description. Simulating the numerical example by MATLAB, the simulation results match with the actual physical process, this proved indirectly the validity of the calculation method which we provide in this paper.