A follow-up vehicle control method suitable for local large slope terrain scenes

Abstract

The application discloses a follow-up vehicle control method suitable for local large-gradient terrain scenes, which comprises the following steps: acquiring the motor feedback speed of the vehicle and the elastic force data between the vehicle and the operator in real time, then combining the elastic force change rate and the motor feedback speed change rate according to the respective set debugging parameters, and calculating the comprehensive speed change rate of the vehicle; determining the expected speed of the motor according to the calculated comprehensive speed change rate and the maximum speed limit threshold, and controlling the motor to run according to the expected speed, so as to limit the motor speed from exceeding the maximum speed limit threshold and improve the output torque of the motor. Moreover, the combination of the elastic force change rate and the motor feedback speed change rate enables the system to soften the acceleration process according to the state of the person and to rely on the speed closed loop to maintain stable output, so that the vehicle can pass the gradient terrain in a stable and controlled manner under the premise of guaranteeing the safety and comfort of the person.

Description

Technical Field

[0001] This invention relates to the field of vehicle automatic following control technology, and specifically to a following vehicle control method applicable to local steep slope terrain scenarios. Background Technology

[0002] The basic principle of a towed, self-following vehicle is to connect the vehicle to a person via a connecting structure. A sensor system is installed on this structure. As the person pulls the vehicle, the sensors collect real-time data on force changes or relative displacement between the vehicle and the person. Based on this data, a following algorithm is used to automatically control the vehicle's drive motor, allowing the vehicle to automatically adjust its speed and follow the person. This type of towed, self-following vehicle is typically used for transporting goods. Goods are loaded onto the vehicle, and a person pulls it via the connecting structure; the vehicle then automatically follows, driven by electricity, to transport the goods. Compared to simply pulling a cart manually or carrying heavy loads, this type of towed, self-following vehicle significantly reduces human labor.

[0003] However, when faced with challenging terrain featuring steep inclines, the vehicle's drive motor needs to output significant torque to overcome the resistance of such terrain. The existing following algorithm dictates that the motor speed closely follows the operator's movements. In this situation, the operator subconsciously increases speed to utilize inertia to traverse the slope. However, the vehicle motor's output characteristic is that torque decreases with higher speeds, causing the motor to become stuck on the slope and lose speed output. Subsequently, the operator will further accelerate to try and pull the vehicle out, and the following algorithm will continue to respond to the acceleration, further increasing the motor speed and continuously decreasing the torque, ultimately creating a vicious cycle that prevents the vehicle from traversing the terrain. This severely impacts the off-road capability and complex terrain handling performance of following vehicles. Summary of the Invention

[0004] This invention aims to solve the problem that existing following vehicles are prone to motor jamming and inability to pass under harsh terrain such as steep slopes in their following mode, and provides a following vehicle control method suitable for local steep slope terrain scenarios.

[0005] This invention is achieved through the following technical solution:

[0006] A following vehicle control method suitable for local steep slope terrain scenarios, the implementation steps are as follows:

[0007] Step 1: Determine if a local steep slope is encountered. When a local steep slope is encountered, the vehicle's motor control system switches from the first following mode to the second following mode. The first following mode is suitable for vehicle following control on flat terrain, while the second following mode is suitable for vehicle following control on local steep slopes.

[0008] Step 2: After the vehicle's motor control system enters the second following mode, it acquires the vehicle's motor feedback speed in real time. In addition, it acquires real-time elastic force data between the vehicle and the operator. This elastic force data is obtained by multiplying the spring extension / retraction variation data between the vehicle and the operator by the spring constant. Then, it calculates the elastic force change rate and the motor feedback speed change rate, and combines these two rates according to their respective set adjustment parameters to calculate the vehicle's overall speed change rate. Then, based on the calculated overall rate of change of velocity... and according to the preset maximum speed limit threshold The constraints are used to determine the expected speed of the motor. :

[0009] When the motor feedback speed satisfy At that time, the expected speed , The set time period;

[0010] When the motor feedback speed At that time, the expected speed ;

[0011] The vehicle's motor control system, based on the expected speed To control the operation of the motor.

[0012] In the above technical solution, a mode switching unit is set up. The mode switching unit is wearable and is set on the operator. The mode switching unit establishes a communication connection with the vehicle's motor control system. When the operator determines that he has encountered a local steep slope, he sends a mode switching command to the vehicle's motor control system through the mode switching unit, so that the vehicle's motor control system switches from the first following mode to the second following mode.

[0013] In the above technical solution, a local steep slope terrain automatic recognition unit is installed on the vehicle to automatically determine whether the vehicle is encountering local steep slope terrain. When it is determined that a local steep slope terrain has been encountered, the local steep slope terrain automatic recognition unit automatically sends a mode switching command to the vehicle's motor control system, so that the vehicle's motor control system switches from the first following mode to the second following mode.

[0014] In the above technical solution, the automatic recognition unit for local steep terrain is implemented using a machine vision system. The machine vision system includes a camera and a computational inference processor. The camera captures images of the front of the vehicle, and the computational inference processor runs a local steep terrain recognition model. Based on the captured images, the recognition model identifies whether a local steep terrain has been encountered.

[0015] In the above technical solution, the automatic identification unit for local steep terrain is implemented using a tilt detection system. The tilt detection system detects the vehicle's tilt data in real time and automatically determines whether the vehicle is currently encountering local steep terrain based on the tilt data.

[0016] In the above technical solution, the vehicle is connected to the operator through a connecting structure. The connecting structure is equipped with a spring-type displacement detection device to detect the change in the spring extension and contraction between the vehicle and the operator. The elastic force data is obtained by multiplying the change in the spring extension and contraction data by the spring's elastic coefficient.

[0017] In the above technical solution, the structure of the spring-type displacement detection device is as follows: it includes a housing, a movable pull rod, a slider, a pull-string displacement sensor, a spring mounting rod, a first spring, and a second spring. The slider is installed inside the housing via a slide rail. The pull-string displacement sensor is fixedly installed inside the housing, and the pull-string of the pull-string displacement sensor is connected to the slider. The spring mounting rod is parallel to the slide rail and installed inside the housing. The bottom of the slider is slidably mounted on the spring mounting rod. The first spring and the second spring are fitted onto the spring mounting rod and are located at the left and right ends of the slider, respectively. The slider is connected to one end of the movable pull rod, and the other end of the movable pull rod extends out of the housing for connection to the operator's end. The housing is connected to the vehicle end.

[0018] The advantages and beneficial effects of this invention are as follows:

[0019] This invention effectively solves the problem of motor jamming and inability to pass through steep slopes and other harsh terrains in existing following vehicles. When traversing locally steep terrain, the invention acquires real-time data on the vehicle's motor feedback speed and the elastic force between the vehicle and the operator, calculates the rate of change of elastic force and the rate of change of motor feedback speed, and combines these two rates according to their respective set adjustment parameters to calculate the vehicle's comprehensive speed change rate. Then, based on the calculated comprehensive speed change rate and the preset maximum speed limit threshold, the expected speed of the motor is determined, thereby limiting the motor speed to not exceeding the maximum speed limit threshold and improving the motor's output torque.

[0020] The elastic force data used in this invention reflects both the operator's force intention and the relative displacement changes between the operator and the vehicle. By combining the elastic force change rate and the motor feedback speed change rate according to their respective set debugging parameters, a gradually increasing comprehensive speed change rate (i.e., comprehensive acceleration) can be calculated. The elastic force data can capture the operator's force intention and the relative displacement changes between the operator and the vehicle in real time; the motor speed feedback ensures that the actual vehicle response is smooth and controllable. The combination of the two allows the system to soften the acceleration process according to the operator's state, preventing sudden changes in power that could cause a sharp increase in stress on the operator's waist or a sudden lurch of the vehicle, while maintaining stable output through a speed closed loop. Ultimately, this helps the vehicle navigate sloping terrain in a stable and controlled manner, ensuring the safety and comfort of the operator. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a flowchart of the following vehicle control method applicable to local steep slope terrain scenarios of the present invention.

[0023] Figure 2 This is a schematic diagram of a spring-type displacement detection device. Detailed Implementation

[0024] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the invention. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the invention for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0025] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0026] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0027] To overcome the problem of motor jamming and inability to pass through challenging terrains such as steep slopes in existing following vehicles, embodiments of the present invention provide a following vehicle control method suitable for localized steep slope terrain scenarios. Specifically, see the appendix. Figure 1 The present invention provides a following vehicle control method suitable for local steep slope terrain scenarios, the implementation steps of which are as follows:

[0028] Step 1: Determine if a local steep slope is encountered. When a local steep slope is encountered, the vehicle's motor control system switches from the first following mode to the second following mode. The first following mode is suitable for vehicle following control on flat terrain, while the second following mode is suitable for vehicle following control on local steep slopes.

[0029] For example, a mode switching unit (e.g., a button) can be set up. The mode switching unit is preferably wearable and set on the operator's body. The mode switching unit establishes a connection with the vehicle's motor control system through a wireless module (or a wired connection). When the operator determines that a local steep slope is encountered, the mode switching unit sends a mode switching command to the vehicle's motor control system, so that the vehicle's motor control system switches from the first follow mode to the second follow mode.

[0030] Furthermore, the operator can be either a living human being or a robot. When it is a living human being, the operator makes the judgment on whether a local steep slope has been encountered; when it is a robot, the robot's machine vision recognition system is used to determine whether a local steep slope has been encountered.

[0031] For example, a local steep slope terrain recognition unit can be installed on the vehicle to automatically determine whether the vehicle is encountering local steep slope terrain. When it is determined that a local steep slope terrain has been encountered, the local steep slope terrain recognition unit automatically sends a mode switching command to the vehicle's motor control system, causing the vehicle's motor control system to switch from the first following mode to the second following mode.

[0032] Furthermore, the automatic recognition unit for locally steep terrain can be implemented using a machine vision system. The machine vision system includes a camera and a computational inference processor. The camera captures images of the area in front of the vehicle, and the computational inference processor runs a locally steep terrain recognition model. Based on the captured images, the recognition model identifies whether locally steep terrain has been encountered.

[0033] Furthermore, the automatic recognition unit for locally steep terrain can also be implemented using a tilt detection system. This system monitors the vehicle's tilt angle data in real time and then automatically determines whether the vehicle is currently encountering locally steep terrain based on this data.

[0034] Step 2: After the vehicle's motor control system enters the second following mode, the following processing steps are executed:

[0035] Step 2.1: Obtain the vehicle's motor feedback speed in real time. And real-time acquisition of the elastic force between the vehicle and the operator data.

[0036] Specifically, the vehicle is connected to the operator via a connecting structure. This connecting structure is equipped with a spring-type displacement detection device to detect changes in the spring's extension and contraction between the vehicle and the operator. The elastic force is then calculated by multiplying this spring extension and contraction data by the spring's elastic coefficient. Data. This elastic force It can reflect both the operator's intention to exert force and the changes in relative displacement between the operator and the vehicle.

[0037] For further details, please see the appendix. Figure 2The structure of the spring-type displacement detection device can be as follows: it includes a housing 1, a movable pull rod 2, a slider 3, a pull-rope type displacement sensor 4, a spring mounting rod 5, a first spring 6, and a second spring 7. The slider 3 is installed inside the housing 1 via a slide rail 8. The pull-rope type displacement sensor 4 is fixedly installed inside the housing 1, and the pull rope 41 of the pull-rope type displacement sensor 4 is connected to the slider 3. The spring mounting rod 5 is parallel to the slide rail 8 and is installed inside the housing 1. The bottom of the slider 3 is slidably mounted on the spring mounting rod 5. The first spring 6 and the second spring 7 are fitted onto the spring mounting rod 5 and are located at the left and right ends of the slider 3, respectively. The first spring 6 and the second spring 7 have the same specifications (same elastic coefficient). The slider 3 is connected to one end of the movable pull rod 2, and the other end of the movable pull rod 2 extends out of the housing 1 and is connected to the operator's end. The housing 1 is connected to the vehicle end. When the operator pulls the vehicle, a relative displacement occurs between the movable lever 2 and the outer casing 1. The movable lever 2 synchronously drives the slider 3 to move. During this process, the first spring 6 and the second spring 7 provide elastic force to the slider 3. The displacement h of the slider 3 is detected by the cable-type displacement sensor 4. The extension / retraction of each spring is h, and the total extension / retraction of the springs is 2h. Therefore, the elastic force can be calculated by multiplying 2h by the spring constant. .

[0038] Step 2.2, based on the obtained elastic force between the vehicle and the operator and motor feedback speed The data is used to calculate the rate of change of elastic force and the rate of change of motor feedback speed. These two rates are then combined according to their respective set adjustment parameters to calculate the vehicle's overall speed change rate (i.e., overall acceleration). The calculation formula is as follows:

[0039] In the formula, This is the overall rate of change of vehicle speed (i.e., overall acceleration). The feedback speed change rate of the motor. The rate of change of elastic force between the vehicle and the operator. The first debugging parameter, This is the second debugging parameter. It should be noted here that… For dimensionless parameters, The unit is m / s 2 ; The unit is N / s, since N can be expressed as kg·m / s², therefore The unit is kg·m / s 3 ; The unit is s / kg, therefore The unit is m / s 2 .

[0040] In addition, it should be noted that, and These two tuning parameters are primarily determined through actual testing, with the aim of synchronizing the vehicle's response as closely as possible with the operator's feel. Specifically, It mainly affects the response during emergency stops and rapid starts. When adjusting, you need to see if the vehicle's response can keep up with the operator's actions to avoid the vehicle's response being too slow or too abrupt. This function operates at a constant speed, and its adjustment is based on the amount of force the operator needs to apply to maintain the vehicle's constant speed. These two parameters cannot be set arbitrarily; they are limited by hardware conditions: for example, a person's running speed is approximately 2.2 m / s, the vehicle's motor has a maximum speed of 180 rpm, and the maximum spring force is 120 N. Therefore, the parameters must ensure that the motor speed matches the person's speed, not exceed limits, and also prevent system vibration. After extensive testing, the optimal parameters are... , (s / kg), under a force of 12N to 40N, the safe range of parameters is Between 0.8 and 1.2 Between 9.0 and 30 (s / kg), a smooth response can be guaranteed without system oscillation.

[0041] The purpose of this step is to calculate a gradually increasing overall speed change rate by combining the motor feedback speed change rate and the elastic force change rate between the vehicle and the operator with the set debugging parameters. Among them, based on elastic force The data can capture the operator's force intention and the relative displacement changes between the operator and the vehicle in real time; the motor speed feedback ensures that the actual response of the vehicle is smooth and controllable; the combination of the two enables the system to soften the acceleration process according to the operator's state, preventing the operator's waist from being subjected to a sudden increase in force or the vehicle from lurching forward due to sudden power changes, and to maintain stable output by relying on speed closed loop. Ultimately, under the premise of ensuring the safety and comfort of the personnel, the system helps the vehicle to drive over sloping terrain in a stable and controlled manner.

[0042] Step 2.3, based on the calculated comprehensive velocity change rate and according to the preset maximum speed limit threshold The constraints are used to determine the expected speed of the motor. :

[0043] ①When the motor feedback speed satisfy At that time, the expected speed ( (for the set time period).

[0044] ②When the motor feedback speed At that time, limit the expected speed ;

[0045] The vehicle's motor control system, based on the expected speed To control the operation of the motor, thereby limiting the motor speed to no more than At the same time, the output torque of the motor is increased through speed-torque linkage control logic.

[0046] Step 3: Determine whether the vehicle has passed through a local steep slope. Once it is determined that the vehicle has passed through the local steep slope, the vehicle's motor control system switches from the second following mode to the first following mode.

[0047] For example, a human can determine whether the vehicle has passed through a steep local slope and manually operate the mode switching unit to switch the vehicle's motor control system from the second following mode to the first following mode. Alternatively, machine vision systems, tilt detection systems, or other technologies can be used to automatically determine whether the vehicle has passed through a steep local slope and automatically switch from the second following mode to the first following mode; these will not be elaborated further here.

[0048] It's important to clarify here that this step aims to demonstrate how to switch back from the second follow mode to the first follow mode after traversing a localized steep slope. This means that the vehicle will definitely traverse the current localized steep slope. "Traversing" here can mean: the vehicle successfully crosses the current localized steep slope (i.e., under normal circumstances, with sufficient pulling force from the operator and the vehicle's electric drive, it can cross the localized steep slope); or it can mean: for a localized steep slope that is too steep, even with the operator's full effort, they cannot pull the vehicle across. In this case, the operator can reverse, go around the slope, or disconnect from the vehicle and try to lift and push it forward from behind, or seek help from others to push / pull the vehicle to cross the slope (people won't remain stuck in a situation where they can't cross the current slope; they will definitely try to find a way to cross). All these scenarios are considered as successfully traversing the current localized steep slope.

[0049] The embodiments of the present invention have been described above. However, these embodiments are merely illustrative and not intended to limit the scope of the invention. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of the invention, and all such substitutions and modifications should fall within the scope of the invention.

Claims

1. A following vehicle control method suitable for scenarios with steep local slopes, characterized in that, Includes the following steps: Step 1: Determine if a local steep slope is encountered. When a local steep slope is encountered, the vehicle's motor control system switches from the first following mode to the second following mode. The first following mode is suitable for vehicle following control on flat terrain, while the second following mode is suitable for vehicle following control on local steep slopes. Step 2: After the vehicle's motor control system enters the second following mode, it acquires the vehicle's motor feedback speed in real time. In addition, it acquires real-time elastic force data between the vehicle and the operator. This elastic force data is obtained by multiplying the spring extension / retraction variation data between the vehicle and the operator by the spring constant. Then, it calculates the elastic force change rate and the motor feedback speed change rate, and combines these two rates according to their respective set adjustment parameters to calculate the vehicle's overall speed change rate. a Then, based on the calculated overall rate of change of velocity... a and according to the preset maximum speed limit threshold The constraints are used to determine the expected speed of the motor. : When the motor feedback speed satisfy At that time, the expected speed , The set time period; When the motor feedback speed At that time, the expected speed ; The vehicle's motor control system, based on the expected speed To control the operation of the motor.

2. The following vehicle control method applicable to local steep slope terrain scenarios according to claim 1, characterized in that: A mode switching unit is set up, which is wearable and worn on the operator. The mode switching unit establishes a communication connection with the vehicle's motor control system. When the operator determines that a local steep slope is encountered, the mode switching unit sends a mode switching command to the vehicle's motor control system, causing the vehicle's motor control system to switch from the first follow mode to the second follow mode.

3. The following vehicle control method applicable to local steep slope terrain scenarios according to claim 1, characterized in that: An automatic local steep slope terrain recognition unit is installed on the vehicle to automatically determine whether the vehicle is encountering local steep slope terrain. When it is determined that a local steep slope terrain has been encountered, the automatic local steep slope terrain recognition unit automatically sends a mode switching command to the vehicle's motor control system, causing the vehicle's motor control system to switch from the first following mode to the second following mode.

4. The following vehicle control method applicable to local steep slope terrain scenarios according to claim 3, characterized in that: The automatic recognition unit for local steep terrain is implemented using a machine vision system, which includes a camera and a computational inference processor. The camera captures images of the front of the vehicle, and the computational inference processor runs a local steep terrain recognition model. Based on the captured images, the recognition model identifies whether a local steep terrain has been encountered.

5. The following vehicle control method applicable to local steep slope terrain scenarios according to claim 3, characterized in that: The automatic recognition unit for local steep terrain is implemented using a tilt detection system. The tilt detection system detects the vehicle's tilt angle data in real time and automatically determines whether the vehicle is currently encountering local steep terrain based on the tilt angle data.

6. The following vehicle control method applicable to local steep slope terrain scenarios according to claim 1, characterized in that: The vehicle is connected to the operator via a connecting structure. The connecting structure is equipped with a spring-type displacement detection device to detect the change in the amount of spring extension and contraction between the vehicle and the operator. The elastic force data is obtained by multiplying the change in the amount of spring extension and contraction by the spring's elastic coefficient.

7. The following vehicle control method applicable to local steep slope terrain scenarios according to claim 6, characterized in that: The structure of the spring-type displacement detection device includes a housing, a movable pull rod, a slider, a pull-string displacement sensor, a spring mounting rod, a first spring, and a second spring. The slider is installed inside the housing via a slide rail. The pull-string displacement sensor is fixedly installed inside the housing, and the pull-string of the pull-string displacement sensor is connected to the slider. The spring mounting rod is parallel to the slide rail and installed inside the housing. The bottom of the slider is slidably mounted on the spring mounting rod. The first spring and the second spring are fitted onto the spring mounting rod and are located at the left and right ends of the slider, respectively. The slider is connected to one end of the movable pull rod, and the other end of the movable pull rod extends out of the housing for connection to the operator's end. The housing is connected to the vehicle end.

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