Research On Robot Hand Based On Double Crank Connecting Cod With Adjustable Palm

The rise of the electricity supplier industry has generated huge quantities of logistics and express goods.The packaging of goods picking,transportation,sorting according to transport routes and anther works are boring and heavy,human resource consumption is also huge,so,a mechanical hand is needed instead of manual work.There are great differences in the form,size and material of logistics,express,and packaged goods,It has high requirements for robot's grasping range adaptability and grasping reliability.But,now,the fingers of the manipulator can not change the position and rotation at the same time,It is difficult to meet the requirements of internal packing.To solve this problem,a manipulator based on crank and slider mechanism is proposed in this paper.It can change palm configuration through active control,and actively adapt to different appearance requirements of grasping objects.It has simple structure,convenient control and good adaptability.First,the mechanism analysis and the structure design of manipulator are carried out.The whole manipulator belongs to planar parallel mechanisms driven by two motors.Locate finger,mounting plate and other fixings to form static platform,The moving platform includes adjustable crank,connecting rod and moving fingers.The palm gesture is changed by cooperative control,and the position and angle of the base of the hinge are regulated simultaneously,the manipulator clamps the object by self-locking.Besides,the asymmetry of crank eccentricity,finger installation position and two crank can be manually adjusted to further enlarge the grasping range.The manipulator can achieve three grasping modes,including three point grasping,three finger parallel grasping,two finger parallel grasping and so on.It has the ability to grasp cylinders,spheres,ellipsoids,prisms and asymmetrical objects.The 3D modeling of the manipulator is carried out by UG software,and the model is introduced into ADAMS to simulate the grasping,and the changes of the contact force of each finger are analyzed in three grasping modes.Then,the kinematic model of the manipulator is established.The D-H transformation matrix is used to calculate the actual position coordinates of the fingers of the manipulator during the movement.The actual working space of the manipulator is obtained by sequentially assembling coordinates in MATLAB software.We analyzed the effective grasp scope of manipulator under several grasping modes in workspace.The influence of the adjustable parameters of the manipulator on the working space is analyzed,the direction of the finger contact force is calculated,and the calculation equations of the control parameters are set up respectively according to the results of the three grasping modesThen,the control system of the palm changing manipulator is designed,and the corresponding control program is compiled.The single chip microcomputer development board can be used for simple command control,the simple control of the double motor and the grasping action of the manipulator can be completed,and the complex grab control can be completed by the PC application interface,and the manual control and automatic control function of the manipulator can be realized.At the same time,the motion trajectory of fingers is analyzed,and the change curve of control parameters is obtained when fingers are moving linearly.Finally,the manipulator is made,and the experiments o f the no-load control experiment and the physical grab are carried out to verify the motion characteristics of the manipulator,and the accuracy of the calculation model and the adaptability of the manipulator to the shape of a variety of grasping objects are tested.The results show that the control system functions normally,and the grasping effect and adaptability of the manipulator can meet the anticipated requirements.