Zong Quan Deng

Experimental Research on Drilling and Sampling of Lunar Soil Simulant

China is conducting a lunar exploration mission named “Chang’e project”. The goal of the exploration mission is to obtain the drilling core without breaking the original geological information. Since the characteristics of drilling object in lunar exploration mission are different from the soil on the earth, efforts should be greatly made on special sampling methods, sampling drills and the appropriate sampling strategies. Herein, we proposed a novel drilling and coring method, in which a soft-bag is mounted in a rotary-percussive drill for lunar soil sampling. In the process of lunar soil drilling, the driving parameters of several moving units are strongly coupled. The moving units should work cooperatively in order to acquire high coring rate and low power consumption. The relationship between the coring quantity and the drilling parameters will be discussed through experiments. The research showed a clear correlation between rotary drilling torque, sample quantity and rev-feed ratio under specific lunar soil conditions.

Experimental Research on Temperature Rise of Bit in Drilling Normal and Low Temperature Lunar Soil Simulant

The relation between temperature rise of bit and drilling parameters in drilling lunar soil simulant is studied in this paper through experimentation. Since it is difficult to measure the temperature of bit in the drilling process, fiber Bragg grating temperature measuring system is developed. Then, drilling experiments were carried out in normal and-30°C low temperature lunar soil simulant. This research showed a clear correlation between temperature rise of bit, rotational speed and torque in drilling process under specific lunar soil conditions. And the relations in drilling the two lunar soil simulants have similar patterns.

Transmission Mode Research on the Joints of a Multi-Legged Walking Robot

In order to obtain an optimal transmission scheme for the joints of supported leg of a multi-legged walking robot, the experience, which comes from the research of a large-scale six-legged heavy-duty walking robot, is used for reference. Five kinds of transmission schemes are respectively listed, and they are respectively analyzed in detail. Based on the comprehensive performance comparison, the listing approach is employed to synthetically compare on excellences and shortcomings among transmission schemes. The best transmission scheme is obtained through the comparative analysis, which provides technique support for the design and analysis on the multi-legged walking robot.

A Study on Out-of-Plane Compressive Properties of Metal Honeycombs by Numerical Simulation

To provide theoretical basis for metal honeycombs used as buffering and crashworthy structures, the effect of the cell length and foil thickness on compressive properties of metal honeycombs is investigated by numerical simulation. Numerical results are well consistent with the corresponding experimental results. The numerical results show that metal honeycombs have cyclic buckling when loaded in out-of-plane direction. The thicker the foil is or the shorter the cell length is, the higher the plastic collapse stress is and the plastic collapse stress is much sensitive when cell length is short. The numerical simulation used in this paper can well predict the crush behavior. Single and doubled foil portions of cell walls are also accounted in the FE model. The results demonstrate that the method is effective which can be used in optimization design of buffers.

Mechanical Analysis and Measurement of Parameters of Wheel -Soil Interaction for a Lunar Rover

Mechanical models of the wheel-soil interaction are constructed for a rigid wheel of lunar rover when rolling and steering, based on the theories of terramechanics and passive earth pressure. The mechanical affect of different parameters of the soil to the rigid wheel is analysed, such as drawbar pull, rolling torque and steering torque. Experimental results of a rigid wheel in a kind of dry soil, whose mechanical parameters are some similar to lunar soil, validate the models correct. A novel test-bed and its data acquisition system are also designed for testing the performance of the wheel-soil interaction of lunar rover, and their key technologies concerned are discussed.

Parametric Optimization for a Tapered Deployable Mast in an Integrated Design Environment

Deployable mast has a wide range of applications in aerospace industry. As lower weight of deployable mast can greatly save the cost of launching and higher stiffness can improve the loading capacity. This paper aims at designing a tapered deployable truss with lower weight and higher stiffness. The conceptual design and mobility analysis of tapered deployable module are first introduced. Then finite element model is then presented. The proposed structure is optimized towards the goal of maximizing the fundamental frequency and minimizing the structural weight to enhance its stiffness. In the integrated design environment of iSIGHT, Non-dominated Sorting Genetic Algorithm (NSGA-II) is chosen as the optimum tool for this dual objectives optimization issue with four constraints. The Pareto optimal solutions of this optimum problem are found after optimization. Simulation shows that the optimum value of design variables have the capability of enhancing the fundamental frequency by 17% and reducing structure weight by 8%.

Thermal Test of Lunar Rock Drill Bit in Vacuum Environment

Drilling samples of lunar soil is an important and indispensable part of Chinas lunar exploration project. The drill bit temperature during the drilling process is one of the key concerns for scholars, especially for the hard lunar rock drilling in vacuum environment. In this article, a fiber grating temperature measurement system integrated with vacuum drilling system is established. Experiment on simulated lunar rock in atmospheric and vacuum environments is taken out and compared.

Design and Implementation of a Large-Scale Gravity Compensation System for Lunar Rover

This article presents knowledge on the design of a large-scale Gravity Compensation System (GCS) for lunar rover. The system comprises a large-scale planar position servo system that covers an area of 900 square meters and a force servo system that generates compensation force. The major problems in system design are clearly identified so that the mechanisms and control strategies of the GCS could be better understood. Experiment results are also included to extend the knowledge on this system.

Design and Optimization of Magnetic Levitation Actuators for Active Vibration Isolation System

Actuator based on Lorentz force exhibits excellent isolating performance with its non-contact characteristic, especially during frequency bandwidth below 5Hz. In this paper, mathematical model of the magnetic levitation actuator is constructed. In order to obtain better performance, parametric design of the structure of magnetic actuator is carried out and a multi-objective optimization method is proposed to maximize Lorentz force and minimize the mass of coil on the basis of genetic algorithm in the optimization process. A designing optimization program is developed, by which optimized parameters of magnetic actuator with maximal actuator force and minimal mass of coil can be identified to conduct experiment on ground. Compared with initial values in an instance, the optimized method is proven to be feasible and has the value of practical application.

Kinematics Modeling and Driving Spring Design of Truss Structure for Deployable Truss Antenna

To design a truss structure of deployable truss antenna with 7 modules and ensure that the truss structure can be deployed successfully in space environment, kinematics equation of single module with homogeneous coordinate transformation method is built based on the structure and deployment principle of truss structure. By using dynamics software ADAMS, simulation analysis on the deployment is carried out and the driving force of single module is obtained in the ground condition. On this basis, driving spring is designed, and all the important design parameters are obtained. The analytical results show that the driving spring can meet the requirement of deployment in the ground condition. So it can be deployed in orbit (0G). This method can be taken as the theoretical basis for the design and deployment experiment of truss structure.