Kinematics Analysis On Three Dgrees Of Freedom Sphercial Wrist

Robot used in aerospace, deep sea, explosion site, and dangerous environment ho mework has become the hot research and development trend, it can replace to perform the work that human can’t finish. The performance of the robot has an important infl uence on wrist joint, so it is great significance to the wrist of freedom and flexible c ontrol.In this paper, we propose a high-perfomance ball wrist of three dgrees that is co mposed of two hemisheres as the robot wrist. Two hemispheres contact together with certain Angle along the cant.The double active univer jionts transfer the movement of two hemisheres to achieve the pitch and yaw. The third motor drivers outer univer ji ont to realize the roll freedom rotation relying on the suspension bearing.This paper firstly introduces the structre of wrist and working principle, as the structre we establish the mathematical model and deduce the relation betwwen input and out according to the mathematical and space of the knowledge of the geometry.Then we transform the relative angles into the end the implementation of the yaw and pitch attitude and calcluate the transmission ratio of the whole transmission system next we change the relative rotation into motor absolute corner,sothat we can realize the precise control.As the translation and rotation matrix of the ball wrist model we can establish the homogeneous transformation matrix and can get the ball in the speed and acceleration wrist by using matrix analysis and derivation to transformation matrix. In addition, it is strict limited using in aviation and other important areas of the robot in weight, this paper also put forward by using two hemispheres of the coupling movement to realize the ball the wrist rotation movement that two motor can realize three degrees of freedom.This paper uses the matlab to simulate and analyse the relation betwwen two hemispheres’angle and freedom of wrist as the formula of kinematics analysis so that we can get the law of the changing corner.Then we use the analysis software solidworks to simulate the track movement of the wrist. For the first we simulat the most basic movement of wrist that is three degrees of freedom yaw-pitch-roll and then simulate the complex trajectory, we can see that the simulation value is match to the theoretical value.It is proof that the kinematic analysis is correct.Three degrees of freedom spherical robot wrist is expected to solve the problem homework because of restricting of the working scope. It makes the robot work in the bad space conditions possible.