A four-wheel drive electric wheelchair all-terrain adaptive system

Abstract

The application relates to a four-wheel drive electric wheelchair all-terrain adaptive system, belonging to the technical field of electric wheelchairs, which comprises a control module and a wheelchair body, wherein the wheelchair body comprises a wheel module and a sensing module which are electrically connected with the control module; the direction in which the occupant of the wheelchair body faces is the front, the wheel module comprises two front wheels arranged at the front of the wheelchair and two rear wheels arranged at the rear of the wheelchair, the two front wheels and the two rear wheels each comprise a driving motor, and a plurality of driving motors are electrically connected with the control module; the sensing module comprises four sensing sub-modules, the four sensing sub-modules are arranged on the two front wheels and the two rear wheels, any sensing sub-module is used for monitoring the bearing pressure of the wheel and transmitting the bearing pressure data to the control module, and the control module instructs the corresponding driving motor of the remaining wheels to increase the output power when one of the bearing pressure data is lower than a threshold.

Description

Technical Field

[0001] This invention belongs to the field of electric wheelchair technology, specifically relating to an all-terrain adaptive system for a four-wheel drive electric wheelchair. Background Technology

[0002] With advancements in medical technology and services, and the aging population trend, the demand for services for the elderly or people with mobility impairments is increasing. Among these, electric wheelchairs, as a mobility aid for people with mobility impairments, have a wide range of applications and a large user base, making them of great significance for improvement.

[0003] Typical electric wheelchairs are dual-wheel drive, meaning the two large rear wheels are the drive wheels, and the smaller front wheels serve as steering, load-bearing, and driven wheels. In poor road conditions, these wheelchairs are prone to slipping, tilting, and poor starting and braking. To address this, Chinese patent CN106038103A discloses a four-wheel independent drive control system for electric wheelchairs, including a universal control handle, function buttons, a DSP controller, and four electric drive controllers that respectively control the left rear, right rear, left front, and right front wheel motors. The electric drive controllers are connected to the DSP controller via a CAN bus. The DSP controller is electrically connected to the universal control handle. The function buttons include a power switch, a wheelchair motion mode selection button to control the wheelchair's movement or rotation, a rotation mode selection button to control the wheelchair's counterclockwise or clockwise rotation, and a driving mode selection switch to control the wheelchair's forward or backward movement. The DSP controller calculates the speed and direction based on the settings on the control handle and function buttons, and then sends the output information to the drive controller via the CAN bus. The drive controller uses a dual-loop PID controller for torque and speed to control the four hub motors, so as to achieve coordinated output of different directions and speeds by the wheels.

[0004] Although it improves versatility and smooth driving on flat ground by setting independent drive motors for each of the four wheels to achieve four-wheel drive, in actual use, it often faces off-road scenarios. The simple four-wheel drive solution cannot solve problems such as slippage. For example, when one wheel slips or is suspended in the air, the above solution can only continue to drive the four wheels as in the normal scenario, and cannot make adaptive adjustments for such scenarios, resulting in poor off-road performance. Therefore, there is a need for a four-wheel drive electric wheelchair all-terrain adaptive system that can combine the advantages of four-wheel drive, independently adjust wheel output, and has stronger terrain adaptability. Summary of the Invention

[0005] To address the aforementioned problems in the existing technology, this invention provides a four-wheel drive electric wheelchair all-terrain adaptive system, which combines the advantages of four-wheel drive, independently adjusts wheel output, and has stronger terrain adaptability.

[0006] The objective of this invention can be achieved through the following technical solutions: A four-wheel drive electric wheelchair all-terrain adaptive system includes a control module and a wheelchair body, wherein the wheelchair body includes a wheel module and a sensing module that are electrically connected to the control module respectively; With the direction the occupant of the wheelchair is facing forward as the front, the wheel module includes two front wheels located at the front of the wheelchair and two rear wheels located at the rear of the wheelchair. Each of the two front wheels and the two rear wheels includes a drive motor, and the plurality of drive motors are electrically connected to the control module. The sensing module includes four sensing sub-modules, which are respectively installed on the two front wheels and the two rear wheels. Each sensing sub-module is used to monitor the pressure on the wheel and transmit the pressure data to the control module. When the control module determines that the pressure data of one of the wheels is lower than a threshold, it instructs the corresponding drive motors of the other wheels to increase the output power.

[0007] As a preferred embodiment of the present invention, it further includes a control system, which includes a joystick electrically connected to a control module. The control module is used to receive signals from the joystick and decompose the signals into linear velocity and steering angle. The control module is used to instruct the drive motors corresponding to the four wheels to operate according to the linear velocity and steering angle.

[0008] As a preferred embodiment of the present invention, any of the front wheels is connected to the wheelchair body via a swivel wheel, and any of the swivel wheels is electrically connected to a control module, wherein the control module is used to command the rotation angle of the swivel wheel.

[0009] As a preferred technical solution of the present invention, it also includes a scene perception module, which is used to identify whether the wheelchair body is in a stair climbing scene and upload the identification result to the control module.

[0010] As a preferred embodiment of the present invention, a display panel is further included, which is electrically connected to the control module and is used to display the output signals of the operating system.

[0011] As a preferred embodiment of the present invention, the diameters of the two front wheels are equal, the diameters of the two rear wheels are equal, and the diameter of the front wheels is smaller than the diameter of the rear wheels.

[0012] As a preferred embodiment of the present invention, the control module receives the pressure data and calculates the difference between any two pressure data. The scene perception module is used to monitor the tilt angle of the wheelchair body and upload the tilt angle data to the control module. The control module calculates the comprehensive tilt risk coefficient based on the maximum value among several differences and the tilt angle data. When it is determined that the comprehensive tilt risk coefficient exceeds the coefficient threshold, it instructs the corresponding drive motors of all wheels to reduce the output power.

[0013] As a preferred technical solution of the present invention, the control module calculates the comprehensive tilt risk coefficient Z based on the maximum value Cmax among several differences and the tilt angle data Q, and instructs the output power of the corresponding drive motors of all wheels to be adjusted to X times the original value, where X=Z0 / Z, Z=(Cmax / C0)×(Q / Q0)×d, Z0 is a pre-input coefficient threshold, C0 is a pre-input difference threshold, and Q0 is a pre-input tilt angle threshold.

[0014] As a preferred technical solution of the present invention, when the comprehensive tilt risk coefficient is greater than the coefficient threshold, the control module determines the tilting side and the sinking side. When the control module determines that the difference is greater than the difference threshold and the tilt angle data is less than the tilt angle threshold, it corrects the overall rotation speed of the sinking side downward and corrects the rotation speed of the tilting side upward.

[0015] The beneficial effects of this invention are as follows: (1) By setting up a sensor module on the basis of the four-wheel independent drive system, the control module can take advantage of the four-wheel system's ability to independently adjust the output power of each wheel according to the load-bearing pressure uploaded by the sensor module. In off-road scenarios, the output power of the wheels that are not slipping and suspended can be increased, and the system can be driven in stair scenarios. A single system can simultaneously achieve smooth driving on flat ground, stable driving in off-road scenarios, and driving through staircases, thereby improving the system's functionality and versatility. (2) By setting the control module to calculate the difference between any two pressure data and then combine the tilt angle data to calculate the comprehensive tilt risk coefficient, when the pressure on the two wheels is inconsistent, it indicates that the center of gravity of the wheelchair and the user on it is shifted to a large extent, or the tilt angle of the wheelchair itself is large, resulting in a large comprehensive tilt risk coefficient, the control module instructs the corresponding drive motors of all wheels to reduce the output power; when the tilt risk is large and it is not advisable to perform any violent maneuvers, the corresponding drive motors of all wheels are instructed to reduce the output power, thereby reducing the speed and reducing the probability of an accident. (3) When the control module determines that the overall speed of the sinking side is greater than the coefficient threshold and the difference is greater than the difference threshold and the tilt angle data is less than the tilt angle threshold, the control module corrects the overall speed of the sinking side downward and the speed of the tilting side upward. This makes the control module correct the overall speed of the sinking side downward and the speed of the tilting side upward when the current tilt angle is not large but the center of gravity is large. When the steering can be adjusted and the centrifugal trend can be used to adjust the center of gravity, the control module corrects the overall speed of the sinking side downward and the speed of the tilting side upward, forming a differential speed based on the tilt direction. This makes the wheelchair tend to turn in the tilt direction, thereby making the center of gravity return to the center of gravity away from the current tilt direction. This reduces the probability of accidents by utilizing the characteristics of a four-wheel drive wheelchair. Attached Figure Description

[0016] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0017] Figure 1 This is a block diagram of the control loop of the present invention. Detailed Implementation

[0018] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided.

[0019] Please see Figure 1 A four-wheel drive electric wheelchair all-terrain adaptive system includes a control module and a wheelchair body. The wheelchair body includes a wheel module and a sensing module that are electrically connected to the control module. Specifically, in this embodiment, the wheelchair body includes at least a chassis, a seat on the chassis, and a wheel module mounted on the chassis. Optionally, the seat and the chassis are hinged, and the tilt angle of the seat relative to the chassis is adjusted under the command of the control module. In the existing technology, although four-wheel independent drive electric wheelchairs have emerged, when these wheelchairs encounter complex road conditions, such as when one wheel drives into a pothole or runs over a protruding stone, causing the wheel to be suspended in the air or the contact pressure with the ground to decrease sharply, the suspended wheel will spin in the air due to the loss of resistance, while the control system will continue to output power to it. This not only wastes energy, but more seriously, it will cause the vehicle to lose power, making it impossible for other wheels with traction to obtain enough power, causing the wheelchair to slip, dig in the ground, or even be unable to pass through obstacles at all. Therefore, with the direction the wheelchair occupant is facing as the front, the wheel module includes two front wheels located at the front of the wheelchair and two rear wheels located at the rear of the wheelchair. Each of the two front wheels and the two rear wheels includes an independent drive motor. The four drive motors are electrically connected to the control module, so that the output power of each wheel can be independently controlled, providing a hardware basis for realizing power distribution. The sensing module includes four sensing sub-modules, which are respectively installed on the two front wheels and the two rear wheels. Each sensing sub-module is used to monitor the pressure between the wheel and the ground in real time and continuously transmit the pressure data to the control module. The control module has a preset pressure threshold. In this embodiment, the pressure data specifically includes the sum of the supporting force exerted on the wheel by the ground and the rotational resistance of the wheel itself. During normal operation, the ground provides support to the wheels, enabling them to perform their supporting function. At the same time, the wheels need to overcome rotational resistance as they move forward. At this time, the sum of the support force and rotational resistance on the wheels is relatively large. However, when the wheels slip due to driving into soft ground or other terrain, the rotational resistance is small. Or when the wheels are suspended in the air, the ground support force approaches zero, leaving only a weak rotational resistance, which causes the pressure data to be significantly lower than the threshold. When the control module receives data and determines that the pressure data of one of the wheels is lower than the threshold, it determines that the wheel has become suspended or has a serious slippage, and marks the wheel as a problem wheel. At this time, the control module will immediately instruct the drive motors corresponding to the other three wheels to increase the output power, while reducing the power output to the problem wheel. When the vehicle encounters bad terrain, it can automatically concentrate all the power to the wheel with traction, preventing power loss and slippage caused by a single wheel being suspended. By incorporating a sensor module into a four-wheel independent drive wheelchair system, the control module leverages the advantage of the four-wheel system's ability to independently adjust the output power of each wheel based on the load-bearing information transmitted from the sensor module. In off-road scenarios, the output power of the wheels that are not slipping and suspended in the air can be increased, and the system can also drive up stairs. A single system simultaneously achieves smooth driving on flat ground, stable driving in off-road scenarios, and driving when going up and down stairs, improving both the system's functionality and its versatility.

[0020] The above solution only addresses the power distribution issue. Traditional joystick control methods often directly map the joystick's deflection angle to the wheel speed, resulting in stiff movements during starting and turning, easily causing jerking and swaying. This provides a poor experience for users with weaker body control and poses safety hazards. Therefore, a control system is also included, which includes a joystick electrically connected to the control module. The user issues driving commands by pushing the joystick. The control module receives electrical signals from the joystick and decomposes these signals into target linear velocity and target steering angle. The target linear velocity is determined by the magnitude of the joystick's push in the forward / backward direction, while the target steering angle is determined by the magnitude of the joystick's push in the left / right direction. For example, if the user pushes the joystick 30% of its maximum travel in the forward / backward direction and 20% of its maximum travel in the left / right direction during a particular joystick push, then the control module will resolve the target linear velocity to be 30% of the rated linear velocity and the steering speed to be 20% of the maximum steering speed. Optionally, in order to further improve the smoothness of starting and stopping, the control module performs smooth acceleration and deceleration processing on the calculated target linear velocity and target steering angle respectively, that is, further reducing the rate of change in the initial and final stages of acceleration to avoid sudden acceleration. After completing the above smoothing process, the control module will calculate the processed linear velocity and steering speed to obtain the target speed that each of the four drive motors should execute, and instruct the corresponding drive motors to run. In addition, to further optimize steering flexibility, each front wheel is connected to the wheelchair body via a swivel wheel controlled by the control module. When the control module determines that a turn is needed based on the steering angle, in addition to instructing the left and right wheels to produce a differential speed (for example, when turning left, reduce the speed of the left motor and increase the speed of the right motor), it will also instruct the swivel wheel to actively rotate to the corresponding angle, thereby achieving a smaller turning radius and allowing rotation to be completed on the spot as needed. By combining the aforementioned path planning and steering control, this system enables the wheelchair to follow the joystick commands smoothly and in real time, with a fast response and smooth movements, effectively improving maneuverability and ride comfort in confined spaces.

[0021] In some situations, users need to maneuver electric wheelchairs to cross steps. During the process of crossing steps, the wheelchair's posture and the force on the wheels are different from those on flat ground and off-road. At this time, the strategy of simply distributing power to other wheels no longer works. For example, when going up stairs, the front wheels need to provide an upward "lifting" force, while the rear wheels need to provide a forward "pushing" force. If the power distribution is not appropriate, the wheelchair may tip over or be unable to climb the steps. Therefore, a scene perception module is also included. Optionally, the module integrates a gyroscope or accelerometer to identify changes in the wheelchair's posture. For example, when the front of the wheelchair begins to tilt upwards continuously, accompanied by pressure on the front wheels pointing towards the rear of the wheelchair (i.e., the wheels hitting the edge of the step), the scene perception module determines that the wheelchair is entering a step-crossing scenario and uploads this recognition result to the control module. The control module executes a preset step-crossing power distribution program. This program instructs the two drive motors located at the rear to drive the wheelchair horizontally forward, allowing the front wheels to closely contact the vertical sidewall of the step. In conjunction with the climbing action of the front wheels, when the front wheels are in close contact with the vertical sidewall of the step, the two drive motors of the front wheels are instructed to reduce their speed and increase their torque, causing the front wheels to move upward along the sidewall of the step, thereby raising the front of the wheelchair until the front wheels cross the edge of the step. At this point, the rear wheels continue to move forward, allowing the front wheels to climb onto the new step, completing the step crossing. By coordinating the front and rear wheels, the wheelchair can traverse steps with continuous and stable movements, thereby extending the mobility of electric wheelchairs from flat roads and natural off-road surfaces to structured stepped surfaces, further improving the system's functionality and versatility.

[0022] In the above solution, the system mainly focuses on the power redistribution when a single wheel slips or hangs in the air. However, when the wheelchair is traveling on a slope or making a sharp turn, there will be a significant difference in the pressure borne by the left and right wheels. This difference reflects a lateral shift in the center of gravity of the body, which is an important precursor to an impending rollover. If the system still drives in the conventional manner at this time, once the roll angle is too large or the speed is too fast, the wheelchair is at risk of rolling over, causing harm to the user. To address this problem, after receiving the pressure-bearing data, the control module calculates the difference between any two pressure-bearing data. The scenario perception module is used to monitor the tilt angle of the wheelchair body and upload the tilt angle data to the control module. The control module calculates a comprehensive tilt risk coefficient based on the maximum value among several differences and the tilt angle data, and when it is determined that the comprehensive tilt risk coefficient exceeds the coefficient threshold, it instructs the corresponding drive motors of all wheels to reduce the output power. After receiving the pressure-bearing data from the four sensing sub-modules, the control module calculates the difference between any two pressure-bearing data. The magnitudes of these differences directly reflect the uneven load distribution on the left and right sides of the wheelchair. For example, assuming the numbers of two small wheels are wheels 1 and 2, and the numbers of two large wheels are wheels 3 and 4, wheels 1 and 3 are on the same side, and wheels 2 and 4 are on the same side. When wheels 1 and 3 are hanging in the air and wheels 2 and 4 are in contact with the ground, the corresponding pressure-bearing data of wheel 1 and wheel 4 are different, and the difference is large at this time. When wheels 1 to 4 are all in contact with the ground and the center of gravity is above the four wheels, the pressures of wheels 1 to 4 are similar, and the difference is small. At the same time, the scenario perception module is also used to continuously monitor the tilt angle of the wheelchair body, which reflects the slope of the road surface where the wheelchair is located and the roll attitude of the body itself, and uploads the tilt angle data to the control module. The control module calculates a comprehensive tilt risk coefficient Z based on the maximum value Cmax among several differences and the current tilt angle data Q. Specifically, Z = (Cmax / C0) × (Q / Q0) × d, where C is a difference threshold pre-entered to represent the safe permission range, Q0 is a tilt angle threshold pre-entered to represent the safe permission range, and d is a constant factor used to adjust the sensitivity. When the calculated comprehensive tilt risk coefficient Z exceeds the pre-entered coefficient threshold Z0, it indicates that the current load offset and terrain slope of the wheelchair have constituted a relatively high risk of rollover, and it is not suitable to perform any violent maneuvers or maintain the current high speed. At this time, the control module will instruct the corresponding drive motors of all wheels to reduce the output power. Specifically, the output power is adjusted to X times the original, where X = Z0 / Z, Z ≥ Z0. When the calculation result shows Z < Z0, the control module takes Z = Z0. When Z is large and the overall tilt risk coefficient is large, X is small. When the control module adjusts the output power to X times the original value, the output power of the corresponding drive motor of all wheels is reduced. By setting the control module to calculate the difference between any two pressure data points and then combining it with tilt angle data to calculate the comprehensive tilt risk coefficient, when the pressure on the two wheels is inconsistent, indicating a significant shift in the center of gravity of the wheelchair and the user, or a large tilt angle of the wheelchair itself, resulting in a high comprehensive tilt risk coefficient, the control module instructs the corresponding drive motors of all wheels to reduce their output power. This ensures that when the tilt risk is high and no violent maneuvering is advisable, the corresponding drive motors of all wheels are instructed to reduce their output power, thereby reducing speed and lowering the probability of an accident.

[0023] Based on the speed limit control based on the comprehensive tilt risk coefficient, the present invention also provides a more refined active intervention strategy for a special but dangerous working condition. Specifically, when the comprehensive tilt risk coefficient Z is greater than the coefficient threshold Z0, indicating that the wheelchair is already in a high-risk state, the system needs to further determine the main cause of the current risk and take intervention measures. There are two common causes of rollover risk: one is that the vehicle body has already developed a large actual tilt angle Q with the terrain, such as driving on a steep transverse slope; the other is that although the current actual tilt angle Q is not large, the pressure difference Cmax between the left and right wheels is already large, which means that the center of gravity of the wheelchair has shifted significantly, such as when the occupant's body tilts to the side or one wheel presses on a high protrusion. In the first case, deceleration is the safest measure. In the second case, where the difference Cmax is greater than the difference threshold C0 but the tilt angle data Q is less than the tilt angle threshold Q0, a better active intervention method can be adopted. Specifically, when the control module determines that the above-mentioned large difference and small tilt angle occur, it will further determine the tilting side and the sinking side. The side with less pressure is the tilting side, and the side with greater pressure is the sinking side. At this time, the control module believes that although the overall body of the wheelchair has not tilted significantly, the center of gravity has shifted to one side, and this shift is caused by the shift of the center of gravity. At this time, the control module performs active differential adjustment, that is, corrects the overall speed of the sinking side wheel downward and corrects the speed of the tilting side wheel upward, while instructing the omnidirectional wheel to turn to the sinking side. At this point, the wheelchair body tends to sink and turn sideways under the action of the omnidirectional wheels. Then, the wheelchair body sinks and turns sideways further under the action of differential speed. As the wheelchair as a whole tends to turn in the direction of the center of gravity shift, the occupant and the vehicle body will have a centrifugal tendency pointing to the outside of the curve. The direction of this centrifugal force is opposite to the current direction of the center of gravity shift, thereby generating a righting torque to help the center of gravity of the vehicle body and the occupant return to the center. By using the centrifugal force of the turn to counteract the center of gravity shift, the wheelchair can actively intervene and resolve the risk of tipping over before the actual tilt angle deteriorates. This is more proactive than a simple deceleration strategy. By adjusting the overall speed of the sinking side and the speed of the tilting side when the "comprehensive tilt risk coefficient is greater than the coefficient threshold, and the difference is greater than the difference threshold and the tilt angle data is less than the tilt angle threshold", the control module corrects the overall speed of the sinking side downward and the speed of the tilting side upward. This allows the control module to adjust the overall speed of the sinking side and the speed of the tilting side upward when the current tilt angle is not large, but the center of gravity is large. When the steering can be adjusted and the centrifugal trend can be used to adjust the center of gravity, the control module corrects the overall speed of the sinking side downward and the speed of the tilting side upward, forming a differential speed based on the tilt direction. This causes the wheelchair to tend to turn in the tilt direction, thereby causing the center of gravity to return to the correct position away from the current tilt direction. This reduces the probability of accidents by utilizing the characteristics of a four-wheel drive wheelchair.

[0024] Furthermore, as a further improvement to the aforementioned system, this embodiment also includes a display panel, which is electrically connected to the control module and used to display the output signals of the control system in real time, such as the current target linear velocity and steering angle, so that users or caregivers can understand the operating status of the wheelchair. In addition, the diameters of the two front wheels are equal, the diameters of the two rear wheels are equal, and the diameter of the front wheels is smaller than that of the rear wheels. This design makes the small front wheels have a smaller steering torque and more flexible steering, while the large rear wheels provide a larger ground contact area and a longer rolling circumference, effectively improving grip, driving speed and stability when crossing obstacles, so that the occupant's center of gravity naturally falls between the two large rear wheels, forming a stable support structure.

[0025] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A four-wheel drive electric wheelchair all-terrain adaptive system, characterized in that: It includes a control module and a wheelchair body, wherein the wheelchair body includes a wheel module and a sensing module that are electrically connected to the control module respectively; With the direction the occupant of the wheelchair is facing forward as the front, the wheel module includes two front wheels located at the front of the wheelchair and two rear wheels located at the rear of the wheelchair. Each of the two front wheels and the two rear wheels includes a drive motor, and the plurality of drive motors are electrically connected to the control module. The sensing module includes four sensing sub-modules, which are respectively installed on the two front wheels and the two rear wheels. Each sensing sub-module is used to monitor the pressure on the wheel and transmit the pressure data to the control module. When the control module determines that the pressure data of one of the wheels is lower than a threshold, it instructs the corresponding drive motors of the other wheels to increase the output power.

2. The all-terrain adaptive system for a four-wheel drive electric wheelchair according to claim 1, characterized in that: It also includes a control system, which includes a joystick electrically connected to a control module. The control module is used to receive signals from the joystick and decompose the signals into linear velocity and steering angle. The control module is used to instruct the drive motors corresponding to the four wheels to operate according to the linear velocity and steering angle.

3. The all-terrain adaptive system for a four-wheel drive electric wheelchair according to claim 2, characterized in that: Each of the aforementioned front wheels is connected to the wheelchair body via a swivel wheel, and each of the aforementioned swivel wheels is electrically connected to a control module, the control module being used to command the rotation angle of the swivel wheel.

4. The all-terrain adaptive system for a four-wheel drive electric wheelchair according to claim 3, characterized in that: It also includes a scene perception module, which is used to identify whether the wheelchair is in a stair-climbing scenario and upload the identification result to the control module.

5. The all-terrain adaptive system for a four-wheel drive electric wheelchair according to claim 4, characterized in that: It also includes a display panel, which is electrically connected to the control module and is used to display the output signals of the operating system.

6. The all-terrain adaptive system for a four-wheel drive electric wheelchair according to claim 5, characterized in that: The two front wheels have the same diameter, the two rear wheels have the same diameter, and the diameter of the front wheel is smaller than the diameter of the rear wheel.

7. The all-terrain adaptive system for a four-wheel drive electric wheelchair according to claim 6, characterized in that: After receiving the pressure data, the control module calculates the difference between any two pressure data. The scene perception module monitors the tilt angle of the wheelchair and uploads the tilt angle data to the control module. The control module calculates the comprehensive tilt risk coefficient based on the maximum value among several differences and the tilt angle data. When it determines that the comprehensive tilt risk coefficient exceeds the coefficient threshold, it instructs the corresponding drive motors of all wheels to reduce their output power.

8. The all-terrain adaptive system for a four-wheel drive electric wheelchair according to claim 7, characterized in that: The control module calculates the comprehensive tilt risk coefficient Z based on the maximum value Cmax among several differences and the tilt angle data Q, and instructs the output power of the corresponding drive motors of all wheels to be adjusted to X times the original value, where X=Z0 / Z, Z=(Cmax / C0)×(Q / Q0)×d, Z0 is the pre-input coefficient threshold, C0 is the pre-input difference threshold, and Q0 is the pre-input tilt angle threshold.

9. The all-terrain adaptive system for a four-wheel drive electric wheelchair according to claim 8, characterized in that: When the comprehensive tilt risk coefficient is greater than the coefficient threshold, the control module determines the tilting side and the sinking side. When the control module determines that the difference is greater than the difference threshold and the tilt angle data is less than the tilt angle threshold, it corrects the overall rotation speed of the sinking side downward and corrects the rotation speed of the tilting side upward.

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