Research Of Hand Force Feedback Device And System

With the development of virtual reality and teleoperation technology, as a new man-machine interface device, force feedback device brings a more intense effect to the operator presence, and creates a more natural human-computer interaction. As a force feedback technology, hand force feedback can be applied to many fields, the study of hand force feedback technology plays an important role on the development of a number of industries. The performance of hand force feedback device will directly affect the performance of the entire system.At present, very few domestic and foreign hand force feedback products are on the market, and most devices are of small measurement range, large volume and complicated cumbersome structure, in terms of structure, accuracy, versatility and stability, it still has much room for development. Aiming at the above problems, this thesis designs a small high-precision three DOF hand force feedback device, and carries out a detailed study of its supporting software and control system. The designed hand force feedback device has strong advantages of high positional accuracy, large work space, good stability and strong versatility, with no coupling among all degrees of freedom,.The main work and innovations of this thesis are as follows. (1)According to the principles and design method of hand force feedback devices, using SolidWorks to design the handle structure, three perpendicular axis of the handle intersect at one point, with no coupling between three directions. Bevel gear transmission is used to increase the compactness of the structure. (2) Completing the design of the force feedback handle system, using two-class method including upper and lower computer systems which exchange data through serial port. Hardware circuit can acquire positional signals and drive motors based on STM32F103 microprocessor. PC software builds a data display module and a three-dimensional virtual scene module, multi-threaded approach is used to enhance the haptic refresh rate. (3) Building models for operator, force feedback handle and virtual environment respectively, modeling the whole system under the information flowing mode of impedance display, giving the conditions to maintain the stability of system according to Hurwitz criterion and discussing the effects from parameters of the virtual environment, zero-order hold and the operator impedance on stability. A control algorithm based on forecast method using autoregression model combined with cubic B-spline interpolation algorithm is proposed, which can improve the stability of the system. (4) Completing some ergonomic experiments based on the hand force feedback system, studying the influence of guide force on the operating efficiency, the influence of reset force, virtual object movement speed and arm length on operating range, researching on the operation scope, speed, trajectory of human body, and comfort level of handle in detail.