Design and Application of Driving Resistance Test Device for Aircraft Tire and Soil Pavement

Abstract

In view of the lack of soil bins for studying the surface interaction between aircraft wheels and soil, this study designed an indoor test bench for aircraft wheels and soil, including a soil container, loading vehicle, and intelligent measurement and control system, to test key parameters such as tire speed and wheel frictional resistance. The test system is capable of achieving speed regulation ranging from 0 to 30 km/h. The vertical load adjustment range with an adjustment interval of 10 kg spans from 90 to 140 kg. The soil type, compaction degree, and other conditions can be modified as per requirements to vary multiple test conditions, thereby enabling us to explore their influence on the driving resistance of the wheels. Moreover, the test data can be collected and processed in real time. A performance test of a wheel–soil table was carried out. The results show that the wheel–soil table test system is stable and reliable and can determine the relationship between the tire and soil, and the structural design of the test system meets the use requirements. In addition, it achieves the target test speed, data acquisition frequency, and stability. In terms of functionality and operational difficulty, the data acquisition of the entire test process is automated, and the test system achieves better informationization than previous methods. The overall operation of the wheel–soil platform is stable and powerful; thus, the model test platform design goal is achieved, and the testing requirements are met.

1. Introduction

Soil pavement has attracted global attention because of its low construction cost, fast construction speed, and ability to meet the emergency take-off and landing requirements of transport aircraft [1,2]. The driving resistance of the aircraft wheels on the soil pavement is one of the most important sources of resistance from the aircraft during take-off and landing [3,4]. It not only affects the surface performance of the soil pavement, but also affects the length of the soil runway. Therefore, it is very important to determine the driving resistance of the wheels on the soil pavement [5]. In order to obtain this information, we must first clarify the interaction between the wheel and the soil.

In previous research, the main way to study the interaction between aircraft tires and the soil runway was to carry out theoretical calculations and full-scale tests of ground vehicles [6,7]. In reality, the driving environment of the aircraft is more complex than can be represented using this method: soil in nature is heterogeneous and non-isotropic, so it is difficult to study this interaction through theoretical derivation. There are some differences between the motion principles of the full-scale testing of the vehicle and those of the testing of the real machine [8], and the running speed of the simulation is much lower than that of the aircraft. Although the accuracy of this method is high, there are still some errors compared with the real situation. Therefore, a wheel–soil table model test is necessary to study the relationship between the aircraft wheels and the soil. Tire–soil model testing is an important means to study the relationship between tires and soil. It has many advantages, including cost efficiency, high test accuracy, fast data acquisition speed, and strong repeatability [9]. In general, it is more efficient than a full-scale test. In a full-scale test, the test involving soil is greatly affected by natural conditions and weather, and the repeatability of the test is low. Through a wheel–soil table model test, the research parameters can be strictly controlled according to the research needs without the limitation of external conditions, to accurately explore the internal mechanisms of the interaction [10].

The wheel–soil test-bed model is widely used in agricultural machinery [11], lunar exploration robots [12,13], and other fields. The test results have great guiding significance for design, performance evaluation, and design optimization [14]. In 1914, George Kuehne first proposed the use of the soil bin test to study tire–soil interaction. Since then, there has been a surge in research on soil bin testing [15]. The initial soil bin has a high input cost and weak power, which represent considerable limitations in the test. Siemens (1964) [16] designed a small soil bin that can test the performance of agricultural machinery. This equipment requires high investment and cannot perform many full-scale tests. Godwin (1980) [17] constructed and designed a multi-purpose soil bin to meet the needs of their test model, which can be used for the testing of full-scale and model agricultural machinery. However, the operation speed of the silo is very slow, only reaching 3 m/s. The University of Botka, Malaysia, designed a soil bin with a mobile frame with a cantilever-mounted tire (2007) [18], which can be used to test the effects of different parameters, including soil conditions, dynamic load, driving speed, and tire pressure. It is a relatively powerful soil bin, but it did not make a considerable breakthrough in test speed. The University of Urmia in Iran built a 23 × 2 × 1 m soil tank (2013) [19] capable of performing single-wheel tests on agricultural vehicle tires. The maximum speed of the test can reach 5.55 m/s, and the maximum vertical load can reach 5 kN, which can enable the measurement of driving resistance. The Federal Technical University of Akure, Nigeria, built a soil bin that can be tested under specific soil conditions (2010) [20], which enables the performance evaluation of reduced models of agricultural tillage tools in terms of drought and soil disturbance.

China’s soil bin testing started later than that of other countries, mainly in the field of agricultural machinery and lunar rovers. The size of the soil bin in the field of agricultural machinery is larger, while that of the soil bin in the field of lunar rovers is smaller, due to the different needs of machinery in different fields. The first soil bin in China was built at the Luoyang Tractor Research Institute. Due to the limitations of the conditions, the test equipment was simple and its function was weak. With the accelerated pace of scientific and technological progress, the soil trough test equipment industry has developed rapidly. Jilin University has developed a series of soil bin test systems since the 1950s [21], which can enable the measurement of subsidence, wheel speed, driving speed, and other parameters, so as to explore tire–soil relationships. Beijing University of Aeronautics and Astronautics designed a soil bin test system for studying wheel–soil interaction, whereby the test platform enables the interconnection of sensors, computers, and control systems (2010) [22]. The Harbin Institute of Technology developed a soil bin for studying the wheel–ground interaction of planetary exploration rovers (2011) [23]. The soil bin is small, and the side wall is made of tempered glass. In the experiment, the influence of the wheels on the soil particles was observed. Li [24] designed an indoor soil bin for testing rotary tillage components, which can be used to explore the relationship between traction resistance, torque, and other parameters and test rate.

In recent years, with the development of and research on soil trough test benches, the soil trough has gradually developed to become intelligent, precise, and fully functioning. The running speed of agricultural machinery and lunar rovers is low, so the soil bin designed to test them is not high and cannot be effectively applied to aircraft tires. The speed of an aircraft running on the ground during take-off and landing can reach more than 60 m/s, which introduces many new requirements regarding the operating speed and test sampling frequency of the soil bin used to simulate the changes in the wheels’ landing parameters. Based on the real-life needs of aircraft, this study designed a wheel–soil platform suitable for exploring the relationship between the wheels and the soil during take-off and landing.

2. Materials and Methods

2.1. Design and Analysis of Soil Bin

The operation of an aircraft on a soil runway is an extremely complex process; thus, in this study, it was simplified to a tire–soil model for analysis. The principle of the wheels running on a soil runway is similar to that of the wheels running on soil ground, and the same principle can be used for this analysis. When driving on soil roads, for the convenience of research, it is assumed that the tire works like a rigid wheel [25], and thus, Bekker’s pressure–sinkage relationship equation should be used, as shown in Equation (1). The theoretical model is shown in Figure 1 below.

$$p=({\displaystyle \frac{k_c}{b}}+k_{\varphi })z^n$$

(1)

In this equation, p is pressure, b is tire width, z is sinkage, and n, k_c, and k_ϕ are parameters describing the relationship between pressure and sinkage.

According to the balance equation of the driven rigid wheel, combined with the subsidence theory and the geometric relationship in Figure 1, the following driving resistance equation can be obtained. The specific calculation process is shown in [25].

$$F={\displaystyle \frac{1}{{(3-n)}^{\frac{2n+2}{2n+1}}(n+1)b^{\frac{1}{(2n+1)}}\cdot {(k_C/b+k_{\phi })}^{\frac{1}{2n+1}}}}{({\displaystyle \frac{3W}{\sqrt{D}}})}^{{\displaystyle \frac{2n+2}{2n+1}}}$$

(2)

The above is the theoretical calculation of driving resistance, but the real situation is more complicated than Equation (2) suggests. Therefore, it is necessary to carry out a model test to verify the driving resistance in real life. The aircraft on the soil road surface is summarized as moving with fast speed and a large vertical load, and the influencing factors of its movement are many and complicated [26,27]. Therefore, it is necessary to design a powerful soil tank for the model test. The soil trough in the field of agricultural machinery is close to our goal in terms of function, but it still has some shortcomings, including running speed, test frequency, accuracy, etc. [28,29].

Based on the influencing factors of exploration, this paper designs a soil bin with complete test functions. The established soil bin needs to increase the speed of the tire to 30 km/h in a 14-m-long acceleration channel, that is, 8.3 m/s, and then stop the test at the end of a 7-m pavement. The pavement can be replaced according to the needs of the test. The direction of the vehicle is one-way, and it undergoes free deceleration after the acceleration section. The width of the pavement is about 1 m, which ensures that the tire can run normally, and the depth of the pavement is greater than 0.6 m, which is the general influence depth of the vertical load.

In view of the above requirements, the soil test bench is designed. The wheel–soil model test bench (hereinafter referred to as the test bench) is mainly used to simulate the interaction between the wheels and the pavement when the aircraft lands. The pavement type can be designed and replaced according to our needs to enable the testing and analysis of the interaction between the wheels and different pavements.

The test platform includes each platform and track. The platform base adopts a reinforced concrete structure, which has sufficient strength and stiffness, and can ensure that cracking, slip, local settlement, and permanent deformation do not occur. The platform base is designed to include each test platform, track, and loading test mechanism. The test platform and track provide safe and reliable structural support for the loading test mechanism. The guide rail provides three dimensions of guidance and support for the driving of the loading vehicle. The functional components of the test platform are shown in Figure 2.

The overall design of the test platform is divided into several areas, including the power cabin, braking section, test section, acceleration section, and starting section. The division of the test platform is shown in Figure 3:

The dimensions (length × width × height), shown in Figure 3, are 24.96 m × 2.932 m × 1.82 m, and the track width is 854 mm.

2.1.1. Bearing Platform

The platform is divided into four sections: starting, accelerating, testing, and braking. The starting section is used to park the loading vehicle and is the initial position of the loading mechanism. The purpose of the accelerating section is to accelerate the test wheel to the initial speed required for the test, to achieve the speed and kinetic energy required for the test, and to ensure the safe and reliable braking of the cart at the end of this section. The test pavement is used to read the test data and observe the interaction between the wheels and the pavement. The purpose of the braking section after the wheel test is to ensure the safe and reliable braking of the loading vehicle. The bearing platform provides a load-bearing and fixed locking interface for track installation, and ensures firmness and reliability between the track and the platform. The installation interface of the loading mechanism provides the load-bearing and fixed locking interface for the installation of the loading mechanism, and ensures that the position of the driving mechanism relative to the track and the pavement is consistent.

2.1.2. Test Track Surface

The vehicle on the test pavement adopts the structure of a box combining a rail and a roller, and the vehicle adopts a welded steel skeleton. The dimensions of the vehicle box are 7000 mm × 1000 mm × 650 mm, and the steel sealing plate is welded inside to accommodate different pavements, such as gravel, soil, and hard pavements. A standard rail is selected for the track, and the roller, made of a steel alloy, is designed according to its structural form. The roller shaft core is designed with a rolling bearing, and the driving force required to move the vehicle is small. The vehicle is moved out of the designed electric steel wire winch drive. When it is necessary to replace the test pavement material, the road surface vehicle starts to drive the electric hinge plate. The vehicle moves with the rail until the signal feedback stops. At this time, the vehicle is parked in the sinking groove of the pavement base.

2.1.3. Power Bay

The power cabin is composed of a servo motor, an electric winch, a wire device, a traction rope, etc., which provides reliable power for the movement of the loading mechanism. When the test is completed, the traction trolley is driven back to the starting position of the test bench by controlling the reverse rotation of the motor. For the servo motor to obtain better starting performance, the winch needs to be lightweight. The winch is made of 2A12-T4 aluminum alloy, which has a light weight, a small moment of inertia, and good starting performance.

The servo motor is the power source of the soil bin. Because of its high cost, it should be practical and economical. The performance requirements of the motor are related to the mass, acceleration distance, and target speed of the loading device, which are analyzed one by one in this study. The mass statistics of the relevant components of the loading device are shown in

Table 1. Mass of loading device-related parts.

Name	Mass (kg)
Loading frame car	62.9
Loading car (including counterweight block)	103.7
Trolley	50.2
Test wheel	30
Total	246.8

.

The contact mode between the loading vehicle and the trolley device on the guide rail is rolling friction, and the friction coefficient μ is 0.1; the total length of the acceleration section is 12.9 m, the acceleration distance is 11 m, and 1.9 m is reserved for motor deceleration shutdown. The trolley device pushes the loading vehicle to accelerate at 11 m to reach 30 km/h (8.33 m/s). A 10% margin is reserved according to the instantaneous speed of 33 km/h (9.16 m/s). Assuming that the acceleration of the loading vehicle on the track is uniform, the uniform acceleration equation is shown in Equation (3):

$$2aS=v^2-v_0^2$$

(3)

The acceleration section S = 7 m, v = 33 km/h (10 m/s) is substituted into the above equation to obtain a = 3.81 m/s². The rolling friction resistance f of the loading device on the acceleration section is shown in Equation (4).

$$f={\displaystyle \sum mg\mu =242.1 \mathrm{N}}$$

(4)

The traction force of the loading device on the acceleration section is F, as shown in Equation (5).

$$F=ma+f=1182.4 \mathrm{N}$$

(5)

According to the technical requirements, when the loading vehicle enters the test section at an instantaneous speed of no less than 30 km/h, the design value of the scheme is 33 km/h according to the instantaneous speed. In actual use, the speed of the servo motor can be adjusted according to the user’s needs. The linear speed of the rope on the winch is v_J, and the linear speed of the trolley is equal to this value, so the reel speed n_J is shown in Equation (6).

$$n_J={\displaystyle \frac{60v_J}{2\pi r}}=437 \mathrm{RPM}$$

(6)

In this equation, r is the radius of the winch drum, which is 0.2 m.

According to the torque equation, the output torque T is shown in Equation (7).

$$T=Fr=236.5 \mathrm{N}\cdot \mathrm{m}$$

(7)

According to the equation calculating the output power of the motor, when the loading vehicle and the trolley device reach a speed of 33 km/h in the acceleration section, the maximum output power required for the motor output is shown in Equation (8).

$$P={\displaystyle \frac{T{n}_J}{9550\eta }}=22.1 \mathrm{kW}$$

(8)

In this equation, the transmission efficiency of the reducer is 0.9 and that of the traction rope is 0.625 (with reference to the driving traction), the motor efficiency is 0.87, and the actual total transmission efficiency of the system η is about 0.49. According to the technical parameters of the motor, a Suzhou Tongjin 200MAH115020 servo motor (Suzhou, China) is selected. The rated power of the servo motor is 24.1 kW, the rated torque is 115 Nm, and the maximum speed is 2500 RPM.

2.1.4. Charger

The loading device is composed of a loading frame car, a loading car, and a trolley. The trolley drives the loading car to move by driving the traction rope. The loading car is composed of a frame car, a loading car, and a hand-operated winch, and the frame moves on the guide rail. The driving mechanism provides the necessary test speed for the loading car, and provides the required loading capacity for the test wheel by increasing or decreasing the counterweight block.

The loading frame vehicle is the carrier of the loading vehicle. The wheel provides reliable structural support for the loading vehicle in the acceleration, test, and braking stages, and transmits the load of the loading vehicle to the track support. The loading frame car is designed with a guide pulley block and a linear slider guided by the loading vehicle, and loading vehicle dials. When working, the guide pulley block ensures that the frame moves on the guide rail to provide guidance for the acceleration, testing, and braking of the loading vehicle. When the loading vehicle is under extreme working conditions (such as the wheel being embedded in the test surface), the guide pulley block’s anti-overturning and anti-torsion abilities can offset the impact load. The guide pulley block can ensure the safe and reliable operation of the wheel acceleration section, the test surface, and the braking section. The loading frame vehicle adopts a lightweight design, with a size of 1000 mm × 616 mm × 900 mm. 6061T6 aluminum alloy profile pipe fittings are used to weld the frame. A manual steel wire hinge plate is installed at the top to enable the loading vehicle to rise, and a guide seat is placed in the middle to facilitate the passage of a traction rope. A limit dial is placed on both sides of the loading frame vehicle, and the other end of the dial is used to support the loading vehicle. In the acceleration section, the dial supports the loading vehicle to ensure that the distance between the wheel and the test road surface is no less than 20 mm.

The loading vehicle adopts a 6061T6 aluminum alloy profile welded frame, with an overall size of 480 mm × 460 mm × 1175 mm. An adjustable limit block is placed on both sides to accommodate the replacement of various wheel specifications. A wheel locking handle is placed on the wheel mounting frame to lock the wheel, and a four-corner linear guide rail installation is match with the slider on the loading frame vehicle.

The cart adopts a 6061T6 aluminum alloy profile welding frame, with an overall size of 1370 mm × 755 mm × 370 mm. An aluminum alloy hinge plate is installed in the middle of the cart to facilitate the return of the loading car. The rear part is the shear pin interface, and the front part is equipped with a shock absorber to enable soft contact with the loading frame car.

Due to the large load on the loading device during the test, in order to carry out the test smoothly, preserve the service life of the test bench, and determine whether the safety standard is met, it is necessary to simulate the key parts of the system.

(1)

Loading Frame Vehicle and Loading Vehicle Landing Stiffness and Strength Analysis

Considering the limit condition, after the loading vehicle arrives on the experimental road surface, the impact of the wheel and the test road surface is completely stopped within 0.1 s. A simplified model of the frame, loading vehicle, loading wheel, and axle is established using ANSYS software (ANSYS 2021 R1) [30], and the direct connection of the three-axis force sensor is canceled. The frame and loading vehicle are made of a 6061T6 aluminum alloy material, and the axle is made of a 40Cr material. A coordinate system is established, with the reverse direction of the loading vehicle in the x-positive direction, the right side of the loading vehicle body in the y-positive direction, and the vertical direction being the z-positive direction.

The following settings are established for the boundary conditions:

• Apply 500 N on the counterweight-fixed surface to simulate 5 counterweight loads;
• Apply −83 m/s² acceleration in the x-positive direction to simulate the emergency stopping of the loading vehicle, and apply 0.4 g acceleration in the z-positive direction to simulate the emergency stopping of the loading vehicle after the dial is opened;
• Apply gravity acceleration of 1 g;
• The fixed-constraint loading wheel touches the ground;
• Restrain the degree of freedom in the y and z directions of the installation surface of the horizontal guide slider on the frame, and release the degree of freedom in the x direction;
• Define the frame and the loading car slider guide rail as having non-separable contact.

The boundary conditions are set as shown in Figure 4:

As shown in Figure 5 and Figure 6, the maximum stress (77 MPa) of the loading vehicle appears at the axle mounting hole; the safety factor is 3.1; the maximum cumulative total displacement of the loading vehicle, which is located in the upper skeleton of the loading vehicle, is about 2.9 mm; and the maximum displacement of the loading vehicle in the x-axis direction, which is located in the upper skeleton of the frame, is about 2.8 mm. The maximum displacement of the loading vehicle in the z direction, which is located in the front vertical guide rail of the installation skeleton, is about 0.65 mm. The maximum stress of the wheel axle appears at the installation with the loading vehicle. The maximum stress is 108 MPa, and the safety factor is 7.2, which meets the design requirements.

The maximum stress of the loading frame car appears at the axle mounting hole (see Figure 7). The maximum stress is 42 MPa; the safety factor is 5.7; and the total displacement of the loading frame car, which is located in the upper skeleton of the frame, is about 2.9 mm. The maximum displacement of the frame in the x-axis direction, which is located in the upper skeleton of the frame, is about 2.8 mm. The maximum displacement of the loading vehicle in the z direction, which is located on the rear side of the skeleton, is about 0.2 mm, which meets the design requirements.

(2)

Brake Stiffness and Strength Analysis of Cart

Considering the extreme working conditions, after the loading vehicle enters the experimental road surface, the trolley stops completely within 0.1 s when braking, and a simplified model of the trolley is established. The trolley adopts a 6061T6 aluminum alloy material. A coordinate system is established, with the reverse direction of the trolley in the x-positive direction, the right side of the trolley body in the y-positive direction, and the vertical direction being the z-positive direction.

The following settings are established for the boundary conditions:

• Apply −83 m/s² acceleration in x-positive direction to simulate the emergency stopping of the loading vehicle;
• Apply gravity acceleration of 1 g;
• Fix the contact surface between the constraint cart and the buffer.
• Restrain the degrees of freedom in the y and z directions of the horizontal guide slider’s installation surface on the trolley, and release the degree of freedom in the x direction.

The boundary conditions of the cart are set as shown in Figure 8:

As shown in Figure 9, the maximum stress of the cart appears at the point of contact with the retarder; the maximum stress is 29 Mpa; the safety factor is 8.2; and the maximum total displacement of the cart, which is located in the middle of the cart, is about 0.18 mm, which meets the design requirements.

According to the above simulation results, the stiffness of the loading device meets the use requirements and can ensure the smooth running of the test.

2.1.5. Stopping Gear

The braking system includes two parts: loading vehicle braking and pushing vehicle braking. As shown in Figure 10, in the part of pushing vehicle braking, the cart and the loading car are separated, the cart stops, and the loading car continues to move forward. In the loading vehicle braking section, the loading vehicle stops. The braking device adopts the combination of an airbag hydraulic buffer and a protective wall panel. The airbag hydraulic buffer can absorb the kinetic energy of the loading vehicle after driving on the test pavement within a distance of 0.5 m. The buffer wall acts as an auxiliary protection function. When the airbag buffer works normally, the buffer wall can absorb a small amount of energy and play a secondary protective role. When the airbag hydraulic buffer fails, the loading vehicle stops safely and smoothly under the action of the damping spring arranged on the buffer wall to protect personnel and equipment.

2.1.6. Control and Data Acquisition System

The control and data acquisition system consists of a servo motor driver and a sensor data acquisition and processing module. The servo driver provides the necessary power support for the loading vehicle on a specific pavement by controlling the rotation of the servo motor. The data acquisition and processing module can collect, process, display, and store the data of the speed sensor and the three-dimensional force sensor. The electric control cabinet is designed to operate and display the whole test system for the display and input terminals.

2.2. Sensor Placement

2.2.1. Three-Axis Sensor

A Shenzhen New Transform Technology Co., LTD (Shenzhen, China) 3KD170 three-axis force sensor is used in this study. When the wheel is driving in the test section, the three-axis force sensor (see Figure 11) can accurately output the force value in the horizontal and vertical directions of the wheel. The three-axis force sensor has a simple structure and a small volume. It converts the mechanical energy of the measured object into an electrical signal output. It has strong anti-interference ability, a wide temperature range, and is not affected by air pollution, oil pollution, and other media at the test site. It is commonly used in electronically controlled engines to determine the current crankshaft speed and position. Through the rotation of the signal disk, cutting of the magnetic field line is achieved, the core body is induced, and the signal output is obtained. This signal is modulated by the internal modulation of the electronic control unit to obtain a square-wave signal with high precision. The measured data can be automatically recorded and stored during the test, and are easy to export.

2.2.2. Speed Sensor

In order to accurately output the driving speed of the loading wheel, the error is set such that it does not exceed 5%. At the maximum speed, the speed acquisition frequency is set to no less than 100 Hz. SPHZ18-2FS speed sensors (see Figure 11) are arranged near the loading vehicle and the wheel to obtain the driving speed of the loading vehicle and the wheel during the test. An SPHZ18-2FS Hall gear speed sensor is small and does not need a power supply, and it can directly absorb mechanical energy from the measured object and convert it into an electrical signal output.

3. Results and Discussion

In this paper, a wheel–soil test bench is designed and tested, as shown in Figure 12. After the construction of the test bench, it is necessary to carry out tests to evaluate its performance. The main test pertained to the software system and its functionality, including the acceleration performance of the trolley, the contact between the loading vehicle and the pavement, the stop performance of the loading vehicle, and the effectiveness of the intelligent data acquisition system.

3.1. Design of Experiments

The soil of the test pavement is loess from the Xi’an area. Before the test, the soil is turned and dried so that the physical properties, such as the water content, of each part of the soil remain uniform. The compaction degree of the pavement is determined by different compaction processes and is formulated according to the test plan. A test operation is carried out according to the test process. In order to make the conditions of the pavement test close to the real conditions of a soil pavement, the compaction degree is set at more than 90% and placed in the natural environment for five days. During this five-day period, the average temperature is 35 °C, and there is no wind or rain. Four experiments were carried out under loads of 93 kg, 113 kg, and 143 kg, respectively. The instantaneous speed of the trolley is greater than 20 km/h at the moment of launching the loading car, and the loading car can stop at the end of the pavement with the help of a deceleration device.

3.2. Principle of Operation

During the test, the trolley transfers power to the loading vehicle under the pulling of the traction rope and enters the test platform after acceleration. Before entering the test platform, the loading frame vehicle drives the loading vehicle to unlock the limit through the support handle on the frame of the kinetic energy collision. The loading vehicle falls freely in the frame through the combination of the linear guide rail and slider until the wheel contacts the test pavement. At this time, the servo motor obtains signal feedback and brakes in response to a signal from the sensor. The trolley is limited by the braking torque of the servo motor to absorb the kinetic energy of the vehicle through the extension of the traction rope and the hydraulic buffer cylinder, so that the trolley and the frame are separated and stopped.

After the acceleration process ends, the wheel falls into and interacts with the test pavement. The average duration of the interaction can be recorded by the speed sensor. The interaction force between the wheel and the test pavement can be obtained by the three-dimensional force sensor installed on the wheel shaft. The speed and force can be recorded by a recording device.

3.3. Analysis of Test Results

During the test, the acceleration and stopping performance of the loading vehicle are good, and the test is carried out smoothly. From Figure 13, it can be seen that the tire of the loading vehicle is in good contact with the road surface, leaving a wheel trace. Figure 14 shows an information acquisition diagram of the driving resistance data acquisition system with 200 Hz acquisition frequency. The data in the figure are divided into two stages, the first stage is the stage where the resistance caused by the bounce of the tire when it has just landed has a large fluctuation. The second stage is the resistance image formed when the tire is rolling steadily, which is also the focus of the article.

Figure 15 and Figure 16 reflect the characteristics of 12 sets of test data. It can be found from this figure that the data of the four consecutive tests under the same test conditions have large variation, but the overall data characteristics are similar, and most of the data are between 200 and 300 N. From the analysis of the box plot in Figure 15, it can verify the fluctuation range of the data, and there are fewer outliers. The fluctuation range in a single set of data is large, but this is caused by the nature of the soil. It can be found from the box diagram that the mean values of each group of data under the same load conditions are similar. The driving resistance values under 93 kg, 113 kg, and 143 kg are 152 N, 180 N, and 265 N, respectively. After testing the model, it is found that the intelligent data acquisition system is stable, the signal transmission is continuous and normal, and the working performance is good.

4. Conclusions

(1) In this study, a wheel–soil test bench composed of a power cabin, a braking section, a test section, an acceleration section, and a starting section was designed, with each section mainly composed of a soil tank and a loading device. The test bench uses a servo motor with a rated power of 24.1 kW and a rated torque of 115 Nm as a power drive, which can achieve a speed adjustment of 0~30 km/h. The range of vertical load is 90~140 kg, with 10 kg as the adjustment interval. ANASYS software was used to simulate and analyze the part of the loading vehicle with a large load in the soil bin. The simulation results show that the design strength meets the use requirements.

(2) The control system of the wheel–soil test-bed monitors the current speed of the test-bed cart, the current speed of the tire, the starting position of the cart, the middle position, the swing rod state of the frame, and the frame state in real time. The intelligent data acquisition system is powerful, and its test operation is simple. This system can perform many functions, such as data acquisition, data storage, and data analysis.

(3) A performance test was carried out on the wheel–soil platform. The mean values of driving resistance test under 93 kg, 113 kg, and 143 kg loads are 152 N, 180 N, and 265 N, respectively, and the mean value of resistance test under the same load does not change significantly. The results show that the wheel–soil platform test system is stable and reliable, and the structural design of the test system meets the use requirements. The target test speed, data acquisition frequency, and stability are achieved. In terms of functionality and operational difficulty, the pavement can be replaced according to the research objective, and the entire data acquisition process of the test is automated. This test system achieves better informationization that previous methods. The overall operation of the wheel–soil platform is stable and powerful, enabling it to meet the needs of the test.