Research on the System of the Rehabilitation Manipulator for Injured Fingers
|School||Harbin Institute of Technology|
|Course||Mechanical and Electronic Engineering|
|Keywords||Rehabilitation Manipulator Continuous Passive Motion CPM Machine Embeded System|
With the development of robotics and the expand of its application, rehabilitation robots, as one branch of robots, are coming into our daily life step by step, and spur the development of rehabilitation theory and the advancement of the clinic-rehabilitation technology. Rehabilitation robotics has gradually become the hotspot in the research field of robotics.Hand-function rehabilitation resulting from hand-trauma or post-operation is a problem which hand-surgeons must face. Now the theory of Continuous Passive Motion has its clinical application step by step, and it is accepted by more and more rehabilitation doctors. In order to provide a hand CPM machine to the patients, an apparatus to doctors for clinical study, we develop a rehabilitation manipulator system. This work is supported by the National Natural Science Foundation of China“Research on the Inteligent Motivated Clinical Bionic Manipulator for the Function Rehabilitation of Injured Hands (Fingers)”(under Grant 60275033). The work is aimed to solve the key problems during the development of the system such as: the rehabilitation theory of the rehabilitation manipulator for injured fingers; structure types design and dimension synthesis of the CPM mechanism; analysis method of the rehabilitation manipupator’s kinematics and dynamics; sensor system design and signal processing of the joint torque/position sensors; embedded system design; rehabilitation mode and clinical practice. The results of the research work will surely improve the level of automatization and intelligentize in hand function rehabilitation.Firstly, we develop the mechanism system of the rehabilitation manipulator and design its rehabilitation Rx on the clinical demand. On demand of the Rx we make functional analysis of human-hand. Then we accordingly designed a structure type of the CPM mechanism which enables multi-joints of the fingers to make continuous passive motion. The base structure of the CPM mechanism is planar four-bar linkage. According to its structural characteristic, we bring forward a dimension synthesis method of planar four-bar linkage based on the mechanical property. The bionic muscle technology is adopted in the system. The whole system is divided into to two modules: one is bionic finger module and the other is bionic muscle module. Linked by the bionic muscles the two modules compose the whole rehabilitation manipulator mechanism system.Secondly, we make kinematics and dynamics analysis of the rehabilitation manipulator. To meet the requirement of grabing exercise, we regard the CPM mechanism of the rehabilitation manipulator and human finger as a whole mechanism to make analysis. By summarizing the method of establishing kinematics and dynamics equations of robots by applying screw theory, we put forward a method of kinematics and dynamics analysis for the rehabilitation manipulator on the basis of screw theory after making the kinematics and dynamics analysis of planar four-bar linkage and dimensional six-bar linkage.Thirdly, we develop the sesor system of the rehabilitation manipulator system. According to the characteristic of the CPM mechanism, we selectively adopt traditional strain measurement principle and integrate the joint torque sensors with their signal processing circuits on the members. We use hall sensors to achieve the untouched measurement of joints’position, their signal processing circuits also being integrated on the joint of the CPM mechanism. The signals’frequency of the joints’torque and positon is very low; we accordingly bring forward an optimum design method of IIR digital filter with the mean square deviation of actual input signals and anticipant output signals in time domain as the optimum target based on the analyis of the main interference source.Fourthly, we develop the rehabilitation manipulator embedded system. We adopt the method of hardware/software codesign. The hadware design of the embedded system adopts the method of function modularization. The core of the hardware system is data acquisition modular and motor control modular based on SPI bus. Combined with the embedded system hardware, the software system is realized by hierarchical parallel competitibe control architecture.Finally, we conduct some tests of the rehabilitation manipulator system, which include systemperformance tests and clinic tests. The rehabilitation mode is also studied.