Dynamics Simulation And Experimental Research Of Multi-clearance Robot Manipulater In The Micro-gravity Environment

The main contents of this article involve two aspects: the experiment of multi-clearance manipulator in the case of ground microgravity and setting up the corresponding verification system. The future development of the spacecraft is long life and high reliability. With long hours of service, friction and wear will occur at the joints, and then there will be gaps. Therefore, studying the effect of clearance on the dynamic characteristics of the mechanical arm system under the microgravity environment can provide theoretical guidance for prolonging the service life of the space manipulator.In this article, the development of space mechanical arm at home and abroad is investigated. In addition, the dynamics of the space manipulator and the status of the microgravity simulation technology are investigated as well. Moreover, the test which is used to prove the planar three joints multi gap mechanical arm is determined and the microgravity by means of air suspension is simulated.Next, according to the requirements of adjustable clearance in the joints, regulating joint clearance by using the method of changing the centre distance of a pair of involute cylindrical gears. The profile parameters of the standard involute gears and the meshing parameters in actual transmission condition are analysed in details. In this way, the relationship between the side gap and the actual centre distance of the gears is derived. Moreover, the contact impact force model of gear with clearance is derived according to the ‘Hertz contact theory’ and its related research results. As the above demands, a three dimensional model of the prototype of the testing verification mechanism is designed and the dynamic model is built on the basis of ADAMS.The function of each key part of the testing mechanism is confirmed based on the above theoretical research and the requirements of the test book, then the detailed design scheme of the mechanism is established. According to the detailed design requirements, the 3D model for each part is designed. In addition, the 3D assembly model of the mechanism is obtained by assembling each part. After making the engineering drawings of each part, processing and assembling those parts, a preliminary test will be started to make sure these parts can meet the design requirements. Some supplementary systems, such as detailed control system, measurement system and gas supply system will provide support for test measurement. Finally, the whole testing verification system is tested to make sure that it can achieve the expected requirements.At last, the research on the dynamic characteristics of testing mechanism can be achieved under the different circumstances by designing the scheme for testing verification system. The dynamic model of the testing verification mechanism is built based on ADAMs, the relevant parameters of the dynamic model is set according to the relationship between side gap and gear centre distance and the contact impact force model. The relationship between dynamic characteristics of a single joint, double joints and triple joints which containing space mechanical arm and gaps of joints are analysed respectively by simulating and analysing the dynamic model of multi space manipulator.