| The implementation of the third phase of lunar exploration project will greatly promote the expanding of the lunar soil drilling and collecting technology, providing the supporting technology for further exploration of other extraterrestrial planets. Shaping mechanism is an important part of the device of drilling and collecting lunar soil. The function of shaping mechanism is to wind and shape soft bag filled with lunar soil sample and place it in sample container. Sample container drops and transfers after completion of shaping sample, falling into the sealed container in the rising vessel. After that, shaping mechanism has avoidance and expansion movement under the action of the expanding mechanism to providing enough space for the rising explorer to take off. However, gravity accelerations and attitudes in the lunar and the earth are different, the low gravity simulation experiment of the expanding and transmitting movement on the ground becomes one of the key research areas in the drilling and sampling.Due to the traditional low gravity experiment method is not universal. In this paper, based on the Lagrange model, a new experiment method for expanding characteristic is put forward, which is a torque compensation method of passive cam profile curve, and simulates the effect of low gravity by offsetting 5/6 heavy torque through the whole course. For the low gravity experiment of lunar soil sample container transmitting, this article adopts momentum equivalent and force equivalent respectively for their impact characteristic and kinematic characteristic.According to the simulation principle, the structural design and analysis of the device in low gravity experiment are carried out, the cam profile curve and the counterweight in the simulation experiment device are designed. The strength and stiffness of the main bearing parts are analyzed. Functional analysis of the driving device and angle adjusting device in the simulation testing device which is for transmitting characteristic is carried out.The theoretical analysis of the error sources in the low gravity simulation device is carried out. The error sources which include the suspension point position, friction and non-coplanar cam mechanism in expanding simulation device are analyzed, the structure of device is improved in order to eliminate or reduce error. The error of the simulation testing for transmitting characteristic is analyzed, and the maximum error which is influenced by the landing attitude is calculated.By using ADAMS, simulations of expanding and sample transfer characteristics of the shaping mechanism are carried out. For deployment characteristic, experiment testing error considering error sources and expanding movement on the lunar surface are mainly simulated. For transmitting characteristic, the impact and the impact velocity on different working conditions are mainly simulated in order to provide comparative data for the test.In this paper, the test platform of the transmitting movement for sample container is built and the test accuracy of sample transmitting simulation device is analyzed. The low gravity simulation tests of impact characteristic and movement characteristic of sample transmitting in different landing angle conditions are carried out. The test results are compared with the simulation data, which verifies the validity of the experiment simulation device.Application value of this subject is that its experiment method can provide reference for other similar tests and its data results of simulation and experiment can be used as a basis to measure the operating performance on the lunar surface of relevant institutions and optimize product. |
PDF Full Text Request