Due to steep slopes and low bearing capacity of lunar crater terrain, conventional planetary rovers are prone to sinking, becoming trapped and failing to climb. To address engineering exploration scenarios, a high-trafficability lunar rover wheel with passive-deformation capability is proposed based on a bionic concept. The wheel has bidirectional driving characteristics. In the forward direction, the wheel functions as a soil-walk wheel with low energy consumption and high moving efficiency. In the backward direction, the wheel functions as a soil-paddle wheel with high trafficability and strong ability to escape being trapped. By adjusting driving direction combination, the rover can enter and cross craters. The soil-paddle piece, which serves as a transformable wheel unit, is mainly composed of a main piece, deputy pieces, a limit plate and springs. The wheel deformation behavior is driven by the interaction between the wheel structure and terrain, without requiring additional actuators, thereby providing passive adaptability. Based on terramechanics theory, the deformation mechanism and wheel performance are analyzed, and size parameters are selected. Rover prototype tests conducted in a simulated lunar terrain environment verify wheel functionality.

Understanding the dynamic failure behavior of soil under impact loading is a fundamental issue at the intersection of geotechnical engineering and terramechanics, and is essential for evaluating soil mechanical properties. However, the macro- and meso-scale response mechanisms of aeolian sand—a typical loose and cohesionless granular material—under high-velocity impact remain poorly understood. In this study, a dynamic impact testing apparatus integrated with high-speed photography and layered tracer particle techniques was developed to investigate the response characteristics of aeolian sand under low-velocity impact. The system enabled non-contact, high-precision tracking of internal particle motion throughout the entire failure process. Based on the observed particle movement, a zoning model of soil failure was established, consisting of an active zone, a transition zone, and a passive zone, which allowed for accurate identification of the internal deformation field and particle trajectories. A dynamic increase factor (DIF) was then introduced to modify the Mohr-Coulomb strength parameters, leading to the formulation of a velocity-dependent prediction model for maximum failure depth. The model predictions agree with experimental results to within 25%, confirming its validity. This study reveals the multi-scale dynamic failure mechanism of aeolian sand under impact loading, providing a theoretical foundation for the analysis of rapid wheel-soil interaction and the stability assessment of soft ground.

The driving speed increase is an important development direction and engineering problem of unmanned planetary rovers. In order to study the influence of driving speed increase on Mars rover driving state when crossing obstacles, a test system was developed and the ground simulation tests of Mars rover prototype were carried out. Aiming at the Mars cruise scene, an experimental scheme including obstacle type and driving speed was proposed. When Mars rover speed increases by about 10 times (30 mm/s-300 mm/s, average results under various experimental conditions), the current and power increase by about 210%, and the energy consumption is reduced by about 60%. With the increase of driving speed, the Mars rover body sway and bump are more obvious. The angular velocity of the body increases by about 470%, and the acceleration increases by about 260%. The peak value of wheel-obstacle force increases by about 140%. The quasi-static model at slow speed and the multi-body dynamics model at fast speed are analyzed. How to optimize high-speed driving and obstacle-crossing state of planetary rover is discussed. This study can provide valuable reference for researchers engaged in design and controller development of high-speed planetary rovers.

Vehicle repeated passes over soft terrain alter the soil’s bearing and shear behavior, thereby affecting vehicle mobility and energy consumption. To address this issue, this study conducted cyclic compression and shear tests on beach sand with moisture contents of 5%, 15%, and 25%. A constitutive model incorporating the coupling effects of loading cycles (N) and moisture content (ω) was developed based on the Bekker and Janosi model framework. The model expresses compression parameters as functions of N and ω, and describes shear behavior through the strength evolution function k(N,ω) and deformation modulus function h(N,ω). Results show excellent agreement between the model predictions and experimental data (R2 > 0.92). Furthermore, a vehicle–soil coupled dynamics model was established based on the proposed constitutive model, forming a comprehensive analytical framework that integrates soil meso-mechanics with full vehicle–terrain interaction. This work provides valuable theoretical and technical support for predicting vehicle trafficability on coastal soft soils and optimizing vehicle suspension systems.

In crewed lunar exploration, elastic metal wheels play an important role in satisfying the mobility and comfort requirements of planetary rovers. In this study, the elastic deformation capability of existing leaf-spring metal wheels is analyzed, and a new type of elastic metal wheel with multidirectional deformation capability is developed to address the insufficient axial elasticity of these wheels. An inner and outer double tread seesaw elastic tread structure is proposed. The radial deformation of the outer tread is converted into outward axial elongation, and the axial deformation is then transferred to the inner tread to amplify the radial deformation. The finite element analysis method is used to simulate the deformation and stress states of the tread under two working conditions: flat compression and unilateral compression. Deformations of 20.260 mm and 16.488 mm are obtained, respectively, and the stress outside the non-jointed end of the tread remains within the yield limit of the material. Based on the application requirements of a crewed lunar rover, a wheel with a diameter of 700 mm and a width of 220 mm was designed, and a seesaw elastic metal wheel is developed. Load-bearing tests and passability tests are carried out. The wheel exhibits excellent load-bearing capacity, high drawbar pull, and elastic buffering capacity. The seesaw tread structure has high anti partial load performance, providing not only continuous elasticity during driving but also effective axial elasticity.

The stable operation of large-aperture radio telescopes such as the Five hundred meter Aperture Spherical Radio Telescope is an important guarantee for continuous scientific output. How to efficiently carry out daily maintenance work under special working conditions such as low load and large slope has become an important issue and difficulty related to astronomical infrastructure. In this study, the working conditions of large aperture radio telescope reflector are analyzed and summarized through field investigation and measurement. A six-wheeled tethered mobile robot scheme based on lightweight flexible wheel sets, three-rocker adaptive suspension and recovery-release platform is developed, and the tether method is used to assist and ensure maintenance work. The theoretical model of maintenance robot system and the lightweight design scheme of main components are established. The maintenance robot system has been successfully verified on the test bench built in laboratory and FAST site,and meets the engineering requirements of actual field operations. The maintenance robot system can realize release, stable movement and recovery of the tethered mobile robot on reflector surface, and replace humans to carry out high-altitude maintenance work more safely and efficiently.

On soft terrain, the rover wheels are easy to slip, sink, or even fail to move. This paper designs a soilplowing wheel which is two-sided closed and without tread. The discrete element simulation shows that the wheel could grasp soil through both sides and plowing soil and that the ability to gain drawbar pull is not significantly reduced. The wheel is fabricated and tested to measure its sinkage, slip rate and drawbar pull. The wheel has high sinking, high slip and high drawbar pull. And the wheel is tested to verify the passability on five terrains of flat ground, climbing, out of sinkage, obstacle crossing and hard ground. The wheel exhibits good passability in all terrains. The soil-plowing wheel is tested verify the passability on three terrains of obstacle crossing, out of sinkage and climbing and using a three-rockers six-wheels rover. The wheel can pass through all terrain. More importantly, the wheel has an excellent ability to get out of sinkage. And it takes only 25.43 s for all six wheels to get out of sinkage. It is believed that the structure and test results of this wheel are valuable for the subsequent development of unmanned rover wheel. (c) 2024 ISTVS. Published by Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

PurposeThe purpose of this study is to develop a planetary rover remote control system based on multi-point relative positioning on the planetary surface, so that astronaut can flexibly control planetary rover in a short distance to meet the real-time and fine operation requirements of human-machine collaborative operation.Design/methodology/approachBy analyzing the human-robot cooperation scene on the planetary surface, a remote control system composed of multi-point positioning elements and remote control-receiving elements is designed. The algorithms of conventional mobile control, limit speed control and autonomous mobile control are developed. The functionality of this system are verified in the simulated planetary surface test field.FindingsThe planetary rover deployed with this system can travel in real time, flexibly and safely under the remote control of astronauts. The multi-point positioning element can accurately obtain the relative position of planetary rover. The planetary rover can successfully return and follow independently in the autonomous mobile mode.Originality/valueThe multi-point relative positioning method of lander-rover-astronaut can efficiently obtain position information. The limit speed control takes into account the astronaut's field of view to enhance the safety of remote control. The autonomous mobile control based on multi-point positioning improves the intelligence of planetary rover.

The complexity of image scene information presents challenges for the trafficability assessment and path planning of Mars rovers. To ensure the operational safety of Mars rovers and extract terrain features from complex image scenes, this paper develops an end-to-end deep learning model, using the deep convolutional neural networks ResNet50 and DeepLabV3 + as the framework, with images from the Zhurong rover's navigation camera as the training and test datasets. A deep learning model suitable for classification and segmentation of terrain in the Mars Utopia Planitia region has been established and applied to planetary geology research. The classification accuracy of model exceeds 83.90% and segmentation accuracy exceeds 80 %. Subsequently, an analysis of 1309 raw images from the navigation camera yielded 203,744 individual estimates of rock abundance, the model evaluates the rock abundance in the Utopia Planitia region, where the Zhurong rover is located, at 10.94 %. The terrain classification model proposed in this study provides both engineering and scientific value for future rovers on the Utopia Planitia. (c) 2024 ISTVS. Published by Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

With the development of deep space exploration, various new exploration missions such as multi-point sampling on the Martian surface and site selection of lunar base put forward higher requirements for the driving distance and efficiency of unmanned planetary rovers. The realization of the high speed of unmanned planetary rovers has become a key way to improve the planetary surface exploration ability. The purpose of this review is to explore the engineering requirements and development direction of the high-speed unmanned planetary rover mobile system. First, the advantages of high-speed exploration in planetary missions are clarified, and the challenges and coping strategies brought by speed improvement are analyzed. Second, the mobile systems are classified and compared, covering elastic, flexible, passive and rigid suspensions based on the existing planetary rover and typical design schemes, and the research progress in high-speed rover design is reviewed. Meanwhile, the key control technologies needed to improve the high-speed driving performance of the planetary rover are systematically summarized, including trajectory tracking, coordinated control, suspension and body control. The technical difficulties and engineering solutions introduced in this review are intended to provide reference for the mobile system design and controller development of a high-speed unmanned planetary rover.

In order to explore the influence of wheel surface structure on the trafficability of planetary rovers on soft ground, three kinds of wheels with different rigid wheel surface structures were selected for research. The basic performance parameters of the wheel on simulated planetary soil are measured and tested to explore the law of the wheel’s sinkage, slip rate and traction coefficient. The results show that the wheel grouser increases the sinkage and slip rate of the wheel. The tread reduces the sinkage of the wheel, but it also reduces the traction performance of the wheel at a higher slip rate. Considering the complex working conditions of the planetary rover on the soft ground, the six-wheeled three-rocker-arm planetary rover is used to carry out passability tests in three terrains: obstacle crossing, out of sinkage and climbing. The results show that the grousers can cause disturbance and damage to the soft soil and have significant passing advantages. There may also be a slip phenomenon when crossing the obstacle, but it does not affect passing. The completely closed tread structure will cause soil accumulation between the tread and the grouser, affecting the wheel’s ability to escape sinkage. This study provides a reference for the design of a rigid wheel surface structure for planetary rovers from the perspective of passing performance.

Bionic walking robots exhibit excellent mobility on rigid terrain. however, their trafficability on soft terrain remains a significant challenge affecting their overall performance. To address this issue, we firstly developed a kinematic model of a bionic walking robot to derive the motion parameters between the footpad and soft terrain. Subsequently, a footpad-terrain interaction model was established to analyze the forces acting on the robot during its movement on soft terrain. An exemplar robot leg was built and three footpads at various walking speed were experimentally tested using a versatile single-legged test bench, various stages of footpad-terrain interactions were recorded and vertical force F1 and horizontal force F2 were measured. The results confirmed that the model could predict the forces with an accuracy greater than 90 %. The minimal differences observed between the experimental and model values suggest that the mechanical model is reliable for force analysis. Therefore, the mechanical model developed in the study could be further determine the forces exerted on the footpads at and defined moments and sinkage, and a layout foundation to understand the stability of walking robots.

A soil bin test facility is a crucial tool for investigating the interaction between terrain and measuring devices under specific field conditions in the field of terramechanics. This paper presents a comprehensive categorization of soil bin test facilities based on their applications and provides a summary of their development in agricultural, vehicle engineering, and deep space exploration. In addition, the paper highlights the improvements made in soil bin test facilities through illustrative examples. A comparative analysis of the structure and characteristics of soil bin test facilities during different periods is presented, along with a summary of their key structural parameters. Furthermore, this study outlines the significance of soil bin test facilities across various fields and presents future development directions. The research findings presented herein serve as a valuable reference for the design, modeling, and innovative optimization of soil bin test facilities.

With the continuous development of planetary surface exploration, the cooperation of planetary rovers has become a potential solution to complete complex and intelligent tasks. The soft terrain and complex environment of the planetary surface also bring difficulties to the satisfaction of the movement and coordination accuracy of planetary rovers. This paper proposes a mobile control strategy based on double virtual springs strategy. The cooperative planetary rover motion model and virtual spring model are established. This method can be applied to the follower planetary rover to realize the following movement of the leader planetary rover according to the cooperative planning. The designed controller was deployed on the rocker-bogie planetary rover prototype, and variable speed test and multi-terrain test were carried out on the simulated planetary terrain. The experimental results show that the mobile control method can effectively improve the relative position and attitude accuracy of the follower planetary rover, and can provide technical support for the development of the cooperative mission.

In order to enhance energy absorption, this study draws inspiration from the diagonal bilinear robust square lattice structure found in deep-sea glass sponges, proposing a design for thin-walled structures with superior folding capabilities and high strength-to-weight ratio. Firstly, the crashworthiness of bionic glass sponge tube (BGSTO) is compared with that of equal-wall-thickness equal-mass four-X tube through both experiments and simulations, and it is obtained that the specific energy absorption of BGSTO is increased by 78.64%. And the crashworthiness of BGSTO is also most significant compared to that of multicellular tubes with the similar number of crystalline cells. Additionally, we found that the double-line spacing of the glass sponge can be freely adjusted without changing the material amount. Therefore, based on BGSTO, we designed two other double-line structures, BGSTA and BGSTB. Then with equal wall thickness and mass as a prerequisite, this study proceeds to design and compare the energy absorption properties of three bilinear thin-walled tubes in both axial and lateral cases. The deformation modes and crashworthiness of the three types of tubes with variable bilinear spacing (beta O/A/B ) are comparatively analysed. The improved complex proportional assessment (COPRAS) synthesis decision is used to obtain that BGSTO exhibits superior crashworthiness over the remaining two kinds of tubes. Finally, a surrogate model is established to perform multi-objective optimization on the optimal bilinear configuration BGSTO selected by the COPRAS method.

Reducing the position and attitude deviation of the planetary rover while driving is an important issue that needs to be considered in the design and controller development of the new types of planetary rovers at this stage. It is also the basis for whether the rovers can carry out exploration missions with high precision requirements on the complex terrain of planetary surfaces. A systematic study of the deviation problems generated by planetary rovers under the most basic open-loop path control is of great significance to improve the effectiveness of planetary detection. In this study, based on simulated Martian terrain and soil, planetary rover driving experiments under various scenes were conducted to test the resulting position and attitude deviation and evaluation indexes under different path types, terrain distributions, driving speeds and steering radius. By combining the experimental phenomena, the action characteristics of single wheel with ground and its influence on the state of the whole vehicle during the deviation generation process are analyzed. And finally, the discussion and conclusion are directed to how to optimize the planetary rover path control. These systematic experiments and analyses can provide valuable references for researchers engaged in the development of mobile controllers for planetary rovers.

To enhance the precision and efficiency of the tractor-failure-rate and equipment-quality inspection, the present study introduces a wireless rapid detection method for assessing tractor quality. For this study, which was based on the symmetrical structural characteristics of tractors, we designed a magnetic suction accelerometer. The test system was composed of a wireless router, a magnetic suction accelerometer sensor, a data-acquisition terminal, and other components. This test system aimed to test the equipment quality of the tractor at idle speed before leaving the factory. The experiment found that the vibration characteristics of the tractor had a symmetrical pattern on the left and right sides of the front and rear axle at idle. When the idle speed of the tractor was 800 r/min and 1000 r/min, the predominant vibration direction of both sides of the front axle of the tractor was the Y direction, while the predominant vibration direction of the rear axle was the Z direction. The experimental results showed that the proposed wireless rapid detection method of tractor quality and the designed acceleration sensor had good testing accuracy. The present study could provide a novel rapid detection method for the failure detection of power machinery in the agricultural field and for inspection before leaving the factory. The implementation of the method could improve the detection efficiency, and reduce the detection cost and the incidence of failure during actual use.

Due to the low gravity environment and the influence of complex terrain condition in deep space exploration, wheeled mobile systems are prone to meet motion abnormalities. The excellent motion performance of walking robot is more suitable for the future deep space exploration, but the robots are prone to occur large sinkage in soft terrain. A mechanical model is built to describe a gait cycle of a walking robot under soft terrain and low gravity environment. The force on the footpad during actual movement in a gait cycle is obtained through a single-legged test bench under the simulated planet terrain. The effects of sizes of footpads, sinkage and other factors are explored. The results indicate that the larger the size of the footpad, the greater the horizontal force on the footpad, the better the motion performance is. But as the size of footpad increase, the vertical force decreases which indicates poor support performance. By comparing and analyzing the model values with the experimental values, for the horizontal force FT, the average errors for the average force and peak force are 10.05% and 7.76%. The average errors for average force and peak force are 5.19% and 5.86% for vertical force FN. The values are not significantly different from the model values and experimental values which indicates that the mechanical model has high accuracy. The obtained mechanical model can provide a reference for the motion of walking robots in complex low gravity environment.

Existing Mars rovers usually adopt a split suspension with a rocker-bogie on each side of the body to improve terrain adaptability. However, when exploring the Martian surface with complex terrain distribution, differential traveling conditions of the wheel sets on both sides can cause the Mars rover to deviate from its desired heading. This paper presents a coordinated wheel speed control method for Mars rovers that combines fuzzy control with active disturbance rejection control. This method can realize real-time heading correction while compensating for the effects of differences in terrain shape and terrain type on both sides. Another advantage of the proposed method is that the control system does not rely on the motion model of the Mars rover's suspension and avoids real-time acquisition of suspension attitude data, which improves the algorithm efficiency and portability. Finally, a series of experimental tests of multiterrain travel were conducted on a six-wheeled Mars rover prototype deploying the control system. The experimental results show that the control system can effectively guarantee that the Mars rover tracks the desired heading while traveling, and can obtain beneficial effects in reducing the internal force between the wheels and facing some special driving scenes.

The assessment of trafficability for planetary rovers in relation to non-geometric hazards is a crucial issue in deep space exploration. This study relies on terramechanics theory and incorporates actual data from Mars soil and rover parameters to develop a model that accurately represents the interaction between the rover’s wheels and Martian soil. Through numerical simulations, this model specifically investigates the relationship between the current of the rover’s wheel drive motor and factors such as slip ratio, soil pressure parameters, and soil shear parameters. Terrestrial experiments are also conducted to verify the precision of certain numerical calculations. The proposed wheel–soil interaction model, based on wheel motor current, provides a foundation for assessing non-geometric trafficability and the inversion of planetary soil parameters.