Obstacle crossing control method for distributed mechanical reinforcement planet probe vehicle

Abstract

The invention belongs to the technical field of obstacle crossing control of planet probe vehicles, discloses an obstacle crossing control method of a planet probe vehicle, and particularly relates to an obstacle crossing control method of a distributed mechanical reinforcement planet probe vehicle. The main controller intelligently selects different single-side and double-side obstacle crossing strategies in combination with real-time road surface information acquired by the sensor. Aiming at the characteristics of different obstacles, the angle of the guide rod reinforcement mechanism is dynamically adjusted through the included angle control motor, the extension length of the guide rod is changed, and the obstacle crossing performance of the planet probe vehicle for different obstacles is improved; meanwhile, in the obstacle crossing process, the system monitors slippage of each driving wheel in real time and dynamically adjusts the underground depth of the guide rod so as to maintain the slippage of the wheels within a reasonable range, and the driving performance of each wheel in the obstacle crossing process is further improved. The obstacle crossing control method provided by the invention can effectively cope with different obstacle characteristics, and improves the obstacle crossing adaptability of the planet probe vehicle to cope with complex environments.

Description

Technical Field

[0001] The invention belongs to the technical field of obstacle crossing control for planetary exploration vehicles, and in particular relates to an obstacle crossing control method for a distributed mechanically amplified planetary exploration vehicle. Background Art

[0002] In the current planetary exploration mission, wheeled planetary exploration vehicles, as the main mobile platform, undertake important tasks such as environmental exploration and data collection. However, planetary exploration vehicles often face the challenge of insufficient obstacle crossing ability in complex terrain, especially when encountering obstacles. Due to the fixed wheel structure, the traditional planetary exploration vehicle obstacle crossing method usually chooses to continuously increase the wheel driving force to achieve obstacle crossing. This method has low driving efficiency and high energy consumption, and it is difficult to flexibly respond to changing terrain and obstacle characteristics. With the increase in the complexity of the exploration mission, the existing wheeled chassis obstacle crossing technology often cannot meet the needs of efficient and stable obstacle crossing. An innovative obstacle crossing control method is urgently needed to improve the obstacle crossing ability and adaptability of the exploration vehicle in various complex environments. Chinese patent CN100418832C discloses a mechanical power-enhanced walking system, which proposes a guide rod mechanical power-enhanced driving walking system, which improves the ability of the wheeled walking system to cross obstacles, but does not dynamically adjust the inclination angle of the guide rod mechanism in real time according to the driving conditions to cope with different terrain and obstacle characteristics. Therefore, in order to address the problem of insufficient obstacle crossing ability of planetary exploration rovers in complex environments, it is of great significance to propose a distributed mechanical booster planetary exploration rover obstacle crossing control method that dynamically adjusts the angle of the guide rod booster mechanism according to different obstacle characteristics to assist in improving the obstacle crossing performance. Summary of the invention

[0003] The purpose of the present invention is to provide a distributed wheel mechanical booster planetary exploration vehicle obstacle crossing control method. According to different terrains and different obstacle characteristics, the main controller combines the real-time road information obtained by the sensor to intelligently select a single-side or double-side obstacle crossing strategy. The angle of the guide rod booster mechanism is adjusted by the angle control motor, and the extension length of the guide rod booster mechanism is changed, thereby increasing the driving force of the driving wheel and the ability to assist in crossing obstacles, aiming to solve the problem of insufficient obstacle crossing ability of the planetary exploration vehicle when encountering obstacles in complex terrain.

[0004] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: the distributed wheel mechanical force-enhancing obstacle-crossing planetary exploration rover includes a frame 1, a suspension 2, an axle 3, a crank 4, a connecting rod 5, a main controller 6, a laser radar sensor 7, a driving wheel 8, a slider 9, a guide rod 10, an angle control motor 11, and a reducer 12.

[0005] The main controller 6 and the laser radar sensor 7 are installed on the vehicle frame as the whole machine controller and the road environment recognition device respectively. The laser radar sensor 7 senses the road surface and obstacle size information in real time and feeds back to the main controller 6. The main controller 6 issues control instructions to the six angle control motors 11 installed at the six sets of driving wheels 8 respectively, adjusts the angle α in real time, changes the extension length of the guide rod, and improves the mechanical force enhancement obstacle crossing for different road environments and obstacles.

[0006] The wheel axle 3, crank 4, connecting rod 5, slider 9, guide rod 10, angle control motor 11, and reducer 12 together constitute the guide rod mechanical force amplification system, and six sets of guide rod mechanical force amplification systems are respectively installed on the six driving wheels 8 of the planetary exploration vehicle. The crank 4 and slider 9 are respectively fixedly connected to the driving wheels 8 and rotate around the wheel axle 3 together with the driving wheels 8. The output shaft of the angle control motor 11 and the reducer 12 are connected to the connecting rod 5 through the keyway to realize transmission. The position of the connecting rod 5 is determined by the angle α. By driving the angle control motor 11 to adjust the angle α between the inner end of the connecting rod 5 and the suspension, the position of the connecting rod 5 is adjusted, and then the extension length of the guide rod 10 is adjusted.

[0007] The guide rod mechanical boost system rotates with the driving wheel 8, and the travel trajectory of the end of the guide rod 10 is a circular curve with the end of the connecting rod 5 as the center and the length of the guide rod 10 as the radius. When the angle α is adjusted by the angle motor so that the connecting rod 5 and the guide rod 10 are collinear in the positive direction, the length between the end of the guide rod and the center of the driving wheel is the longest, and when they are collinear in the reverse direction, the length between the end of the guide rod and the center of the driving wheel is the shortest. By adjusting the angle α to adjust the extension length of the guide rod 10, the driving wheel 8 can be assisted to mechanically boost the obstacle to overcome obstacles of different heights, without consuming the energy of the planetary exploration vehicle to increase the driving force of the driving wheel 8.

[0008] The control process of the distributed mechanical booster planetary exploration vehicle obstacle control method is as follows:

[0009] Step 1: Initialize the system, set parameters such as driving speed, obtain ground information and information about target obstacles ahead through the lidar sensor 7, and determine whether the planetary exploration vehicle can use mechanical force to overcome the obstacle based on the obstacle height h. If the obstacle height h exceeds the planetary exploration vehicle's obstacle crossing limit, choose to bypass the obstacle.

[0010] Step 2: Determine whether the left and right drive wheels need to overcome obstacles at the same time based on the obstacle information and the route of the planetary exploration vehicle. If the drive wheels on both sides need to overcome obstacles at the same time, the angle control motors of the drive wheels on both sides adjust the angle α and keep it consistent, ensuring that the length of the mechanical force guide rods fixed to the left and right drive wheels 8 is consistent, assisting the left and right drive wheels to overcome obstacles with mechanical force at the same time, improving the obstacle-overcoming ability of the whole vehicle and enhancing the stability of the whole vehicle.

[0011] Step 3: Calculate the slip rate S of each driving wheel 8 except the obstacle-crossing wheel during the planetary exploration vehicle's obstacle-crossing process i and the wheel slip rate threshold S set Compare and judge whether the wheel is seriously slipping. i >S set , the main controller 6 issues a control instruction to make the angle control motor periodically adjust the angle α, change the depth of the guide rod 10 into the ground, and thus increase the auxiliary driving force for the driving wheels 8. When the slip rate of each driving wheel 8 meets the set threshold range, the adjustment is stopped.

[0012] The beneficial effects of the present invention are as follows: the proposed method for controlling mechanical force-enhancing obstacles for a distributed planetary exploration vehicle, targeting the special mechanical structure of the guide rod mechanical force-enhancing system, changes the extension length of the guide rod by adjusting the angle α through the angle control motor, thereby increasing the mechanical driving force of the driving wheel and improving the obstacle-enhancing ability. When the exploration vehicle encounters an obstacle, the system obtains information about the road surface and obstacles ahead through sensors such as laser radar, makes an intelligent judgment, and adjusts the angle α through the angle control motor according to different obstacle-enhancing methods. In addition, when the planetary exploration vehicle overcomes an obstacle, the slip rate of the remaining wheels other than the obstacle-enhancing wheel is monitored, the guide rod length is changed by adjusting the angle α, and the guide rod is used for mechanical force-enhancing assistance to increase the driving force of the remaining wheels, thereby improving the driving performance and obstacle-enhancing stability of the entire vehicle, and significantly enhancing the obstacle-enhancing ability of the planetary exploration vehicle in complex environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The figure shows the overall schematic diagram of the distributed mechanical booster obstacle crossing planetary exploration rover system;

[0014] Figure 2 The figure shows the principle diagram of the guide rod mechanical force booster obstacle crossing system;

[0015] Figure 3 Shown is a flow chart of the mechanical booster obstacle crossing control method for a distributed planetary exploration vehicle.

[0016] In the figure: 1: frame; 2: suspension; 3: axle; 4: crank; 5: connecting rod; 6: main controller; 7: lidar sensor; 8: driving wheel; 9: slider; 10: guide rod; 11: angle control motor; 12: reducer. DETAILED DESCRIPTION

[0017] The specific implementation of the present invention is further described in detail below in conjunction with the drawings and examples.

[0018] Figure 1The overall structure of the distributed mechanical booster obstacle-crossing planetary exploration vehicle shown mainly includes: a frame 1, a suspension 2, an axle 3, a crank 4, a connecting rod 5, a main controller 6, a laser radar sensor 7, a driving wheel 8, a slider 9, a guide rod 10, an angle control motor 11, and a reducer 12. The main controller 6 and the laser radar sensor 7 are respectively installed on the frame as a whole machine controller and a road environment recognition device. The laser radar sensor 7 senses the road surface and obstacle size information in real time and feeds back to the main controller 6. The main controller 6 issues control instructions to the six angle control motors 11 installed at the six groups of driving wheels 8, adjusts the angle α in real time, changes the extension length of the guide rod, and improves the mechanical booster obstacle crossing for different road environments and obstacles. The axle 3, crank 4, connecting rod 5, slider 9, guide rod 10, angle control motor 11, and reducer 12 together constitute a guide rod mechanical booster system, and the six groups of guide rod mechanical booster systems are respectively installed on the six driving wheels 8 of the planetary exploration vehicle. The crank 4 and the slider 9 are respectively fixedly connected to the driving wheel 8 and rotate around the wheel axle 3 along with the driving wheel 8. The output shaft of the angle control motor 11 and the reducer 12 are connected to the connecting rod 5 through a keyway to realize transmission. The position of the connecting rod 5 is determined by the angle α. The adjustment range of the angle α is (-180°, 180°). By driving the angle control motor 11 to adjust the angle α between the inner end of the connecting rod 5 and the suspension, the position of the connecting rod 5 is adjusted, and then the extension length of the guide rod 10 is adjusted.

[0019] Figure 2 The figure shows the principle diagram of the mechanical booster obstacle crossing guide rod system. The guide rod mechanical booster system rotates with the driving wheel 8. The length of the connecting rod is s, the length of the guide rod is l, and the travel trajectory of the end of the guide rod 10 is a trajectory circular curve with the end of the connecting rod 5 as the center and the length of the guide rod 10 as the radius. The distance range between the end of the guide rod 10 and the center of the driving wheel 8 is (ls, l+s). When the angle α is adjusted by the angle motor so that the connecting rod 5 and the guide rod 10 are collinear in the positive direction, the length between the end of the guide rod and the center of the driving wheel is the longest, which is l+s. When they are collinear in the reverse direction, the length between the end of the guide rod and the center of the driving wheel is the shortest, which is ls. By adjusting the angle α to adjust the extension length of the guide rod 10, the driving wheel 8 can be assisted to mechanically boost obstacles of different heights without consuming the energy of the planetary exploration vehicle to increase the driving force of the driving wheel 8.

[0020] Figure 3 The figure shows the specific control process of the distributed mechanical booster planetary exploration vehicle obstacle crossing control method. When the distributed mechanical booster planetary exploration vehicle crosses an obstacle, the main controller 6 performs the following steps.

[0021] Step 1: Initialize the system, set the parameters such as driving speed, obtain ground information and information of target obstacles ahead through the laser radar sensor 7, and judge whether the planetary exploration vehicle can use mechanical force to overcome the obstacle according to the obstacle height h. If the obstacle height is higher than twice the driving wheel diameter D, that is, (h>2D), the planetary exploration vehicle will choose to bypass the obstacle. If the obstacle height is within the surmountable range, execute the next step.

[0022] Step 2: Determine whether the left and right drive wheels need to overcome obstacles at the same time based on the obstacle information and the route of the planetary exploration vehicle. If the drive wheels on both sides need to overcome obstacles at the same time, the angle control motors of the drive wheels on both sides adjust the angle α and keep it consistent, ensuring that the length of the mechanical force guide rods fixed to the left and right drive wheels 9 is consistent, assisting the left and right drive wheels to overcome obstacles with mechanical force at the same time, improving the obstacle-overcoming ability of the whole vehicle and enhancing the stability of the whole vehicle.

[0023] Step 3: Calculate the slip rate S of each driving wheel 8 except the obstacle-crossing wheel during the planetary exploration vehicle's obstacle-crossing process i , the specific calculation formula is: Where V is the set speed of the planetary exploration vehicle, w i is the angular velocity of each driving wheel. And it is combined with the set wheel slip rate threshold S set Compare and judge whether the wheel is seriously slipping. i >S set , the main controller 6 issues a control instruction to make the angle control motor periodically adjust the angle α, change the depth of the guide rod 10 into the ground, and thus increase the auxiliary driving force for the driving wheels 8. When the slip rate of each driving wheel 8 meets the set threshold range, the adjustment is stopped.

Claims

1. A distributed wheel mechanical force planetary exploration vehicle obstacle control method, characterized in that: The distributed wheel mechanical force amplification planetary exploration rover includes a vehicle body, a road environment sensing system, six groups of drive wheels and a guide rod mechanical force amplification system, wherein the guide rod mechanical force amplification system includes a wheel axle, a crank, a connecting rod, a guide rod, an angle control motor, and a reducer; the six groups of guide rod mechanical force amplification systems are respectively installed on the six drive wheels of the planetary exploration rover, the crank and the slider are respectively fixedly connected to the drive wheels and rotate around the wheel axle with the drive wheels, the output shaft of the angle control motor and the reducer are connected to the connecting rod through a keyway to realize transmission, and the angle α between the inner end of the connecting rod and the suspension is adjusted to change the angle of the guide rod force amplification mechanism, and the extension length of the guide rod is dynamically adjusted to improve the obstacle crossing ability and driving performance of the wheel.

2. The distributed wheel mechanical force planetary exploration vehicle obstacle control method according to claim 1, characterized in that: The steps include: Step 1: Initialize the system, set the parameters such as driving speed, obtain ground information and target obstacle information in front through the lidar sensor, and judge whether the planetary exploration vehicle can mechanically increase the force to overcome the obstacle according to the obstacle height h. If the obstacle height is higher than 2 times the diameter of the driving wheel, the planetary exploration vehicle will choose to bypass the obstacle. If the obstacle height is within the obstacle-surmountable range, proceed to the next step. Step 2: Determine whether the left and right drive wheels need to overcome obstacles at the same time based on the obstacle information and the route of the planetary exploration vehicle. If the drive wheels on both sides need to overcome obstacles at the same time, the angle control motors of the drive wheels on both sides adjust the angle α and keep it consistent, ensuring that the extension lengths of the mechanical force guide rods of the left and right drive wheels are consistent, assisting the left and right drive wheels to overcome obstacles with mechanical force at the same time, thereby improving the obstacle-overcoming capability of the vehicle and enhancing the stability of the vehicle; Step 3: Calculate the slip rate S of all driving wheels except the obstacle-crossing wheel during the planetary exploration vehicle's obstacle-crossing process i and the wheel slip rate threshold S set Compare and judge whether the wheel is seriously slipping. If S i >S set , the main controller sends a control command to make the angle control motor periodically adjust the angle α, change the depth of the guide rod into the ground, and thus increase the auxiliary driving force for the driving wheels. When the slip rate of each driving wheel meets the set threshold range, the adjustment is stopped.

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