A high-speed omnidirectional self-balancing vehicle and a control method thereof

Abstract

This invention discloses a high-speed omnidirectional self-balancing vehicle and its control method, including a vehicle body, a human-machine input device, at least one front wheel disposed at the front of the vehicle body, at least one rear wheel disposed at the rear of the vehicle body, a drive mechanism, a steering control mechanism, a power module disposed at the bottom of the vehicle body, and an integrated circuit control module. Compared with self-balancing vehicles that operate in a front-to-back direction, the stability of this invention in the front-to-back direction is ensured by the wheel track of the two sets of wheels, thus exhibiting strong high-speed stability and reducing the risk of falling when encountering potholes; compared with self-balancing vehicles that operate in a left-to-right direction, it can maintain balance even when stationary and can perform on-the-spot turns; compared with scooters or bicycles that control direction via handlebars, it allows for hands-free riding, and the wheel direction does not change rapidly to the side when encountering small steps, reducing the risk of falling; and compared with other types of self-balancing vehicles, it is easier to learn.

Description

Technical Field

[0001] This invention relates to the field of self-balancing vehicle technology, specifically to a high-speed omnidirectional self-balancing vehicle and its control method. Background Technology

[0002] Traditional self-balancing scooters are mainly divided into two categories: those that move forward and backward, and those that move left and right.

[0003] Self-balancing scooters: These vehicles maintain balance primarily by controlling acceleration in the forward and backward directions. Lateral balance is not controlled; it is maintained by the wheels or through user intervention. The main drawback of self-balancing scooters is that, considering acceleration, the rider's center of gravity must be precisely above the wheel axle when balancing. The forward and backward center of gravity is significantly affected by changes in acceleration. Therefore, it is very dangerous at high speeds or on uneven surfaces, and the learning curve is relatively steep.

[0004] Left-right self-balancing scooters: These vehicles have at least one of two independent balancing systems. One system uses electronic control to twist the handlebars left and right to maintain balance, similar to the principle of balancing on a traditional bicycle. However, this system is less stable at low speeds or when stationary. A clear example is that bicycles easily tip over during slow-paced races. The other system uses an additional counterweight balancing system. This system typically uses electronic control to move a large mass to maintain balance. Typical examples of this system are gyroscopes and balance blocks. The advantage of this system is that its balancing principle is independent of the vehicle's speed, allowing for balance even when stationary. However, the disadvantages are that when the vehicle is heavily loaded, a large balancer is needed, resulting in high power consumption, and the high-speed rotation or movement of the mass can easily cause injury or death.

[0005] Currently, there is a lack of self-balancing scooters with the following characteristics: 1. High stability at high speeds; 2. Good stability at any speed, whether carrying a person or not; 3. The scooter does not rely on gyroscopes or counterweight-based balancing systems. Static balancing consumes little power and is less prone to causing danger. Summary of the Invention

[0006] Therefore, the present invention provides a high-speed omnidirectional self-balancing vehicle and its control method to solve the problems in the prior art where self-balancing vehicles in the front and rear directions are prone to danger when traveling at high speeds, and self-balancing vehicles in the left and right directions have poor stability when the vehicle is at low speed or stationary.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] According to a first aspect of the present invention, a high-speed omnidirectional self-balancing vehicle is provided, the vehicle comprising a vehicle body, a human-machine input device, at least one front wheel disposed at the front of the vehicle body, at least one rear wheel disposed at the rear of the vehicle body, a drive mechanism, a steering control mechanism, a power module disposed at the bottom of the vehicle body, and an integrated circuit control module.

[0009] The front and rear wheels have a preset distance between them. The vehicle body is provided with a standing area or seating area for personnel located between the front and rear wheels. The human-machine input device is used to acquire user operation intentions or commands. The drive mechanism is connected to the front and / or rear wheels and is used to drive at least one of the front and rear wheels to rotate. The front and rear wheels are connected to a steering control mechanism, which is used to control the steering angle of the front and rear wheels. The power module is used to supply power to the entire vehicle. The integrated circuit control module includes a main control MCU and a tilt angle detection sensor. The tilt angle detection sensor is used to detect the tilt angle of the vehicle body. The human-machine input device, drive mechanism, steering control mechanism, and tilt angle detection sensor are all connected to the main control MCU.

[0010] Furthermore, the human-machine input device includes a pressure sensor installed in the standing area of ​​the personnel, a tilt detection sensor for detecting the tilt angle of the vehicle body, a manual input device, and a remote wireless device.

[0011] Furthermore, the drive mechanism includes a drive motor connected to the drive wheel, and the integrated circuit module includes a motor driver connected to the main control MCU, with the drive motor connected to the motor driver.

[0012] Furthermore, the steering control mechanism includes a steering transmission and a steering servo. The steering transmission is rotatably mounted on the front or rear of the vehicle body. The front and rear wheels are connected to the steering transmission. Gears, belts, chains, or cable devices are provided on the outer side of the steering transmission. The steering servo is mounted on the vehicle body and connected to the steering transmission via gears, belts, chains, or cable devices. The integrated circuit control module includes a steering controller connected to the main control MCU. The steering controller is connected to the steering servo.

[0013] Furthermore, the steering control mechanism also includes a steering angle detection sensor, which is mounted on the transmission device or on the steering servo, and is used to detect the wheel steering angle.

[0014] Furthermore, the front wheel includes a single wheel, and the rear wheel includes a single wheel.

[0015] Furthermore, both the front and rear wheels consist of a single wheel with a certain width, or a set of wheels arranged symmetrically on the left and right sides.

[0016] Furthermore, the vehicle body is equipped with handrails.

[0017] According to a second aspect of the present invention, a control method for a high-speed omnidirectional self-balancing vehicle is provided, the control method comprising:

[0018] The balance control cycle begins, and the tilt angle θ of the vehicle to the left or right is detected by the tilt angle detection sensor;

[0019] The vehicle balance control method is determined based on the current vehicle speed, wheel steering angle, vehicle tilt angle, and user intent or command.

[0020] Based on the determined vehicle balance control method and the corresponding control relationship formula of the vehicle center of gravity tilt angle θ, the two parameters of wheel speed and wheel steering angle are adjusted to change the acceleration a in the left and right directions of the vehicle, and finally to change the tilt angle θ in the left and right directions of the vehicle.

[0021] The vehicle tilt angle after balance adjustment is detected, and the adjusted vehicle tilt angle is compared with the target tilt angle for closed-loop control.

[0022] After the above steps are completed, a new balance control cycle begins.

[0023] Furthermore, the vehicle balance control method includes:

[0024] Variable speed motion is suitable for situations where the vehicle speed is high and the wheel steering angle is small.

[0025] The simultaneous steering of the front and rear wheels during gear shifting is suitable for situations where the user does not need to adjust the direction of the vehicle.

[0026] The curvature motion mode with a constant wheel steering angle in variable speed driving is suitable for situations where the user needs to adjust the direction of the vehicle.

[0027] Uniform speed motion is suitable for situations where the vehicle speed is low and the wheel steering angle is large.

[0028] Uniform speed + variable speed motion is suitable for situations where the vehicle speed is low but still has a certain speed, and the vehicle tilts at a large angle, and is about to fall.

[0029] When determining the balance control method to use, user intent or instructions should be given priority.

[0030] The present invention has the following advantages:

[0031] This invention proposes a high-speed omnidirectional self-balancing vehicle and its control method, comprising a vehicle body, a human-machine input device, at least one front wheel disposed at the front of the vehicle body, at least one rear wheel disposed at the rear of the vehicle body, a drive mechanism, a steering control mechanism, a power module disposed at the bottom of the vehicle body, and an integrated circuit control module. Compared to self-balancing vehicles that operate in a front-to-back direction, the stability of this invention in the front-to-back direction is ensured by the wheelbase of the two sets of wheels, thus exhibiting strong high-speed stability and reducing the risk of falling when encountering potholes; compared to self-balancing vehicles that operate in a left-to-right direction, it can maintain balance even when stationary and can perform on-the-spot turns; compared to scooters or bicycles that control direction via handlebars, it allows for hands-free riding, and the wheel direction does not rapidly change sideways when encountering small steps, reducing the risk of falling; and compared to other types of self-balancing vehicles, it is easier to learn. Attached Figure Description

[0032] To more clearly illustrate the embodiments of the present invention or the technical solutions in 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 merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0033] The structures, proportions, sizes, etc. illustrated in this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0034] Figure 1 This is a structural schematic diagram of a high-speed omnidirectional self-balancing vehicle provided in Embodiment 1 of the present invention;

[0035] Figure 2 This is a schematic diagram of the bottom structure of a high-speed omnidirectional self-balancing vehicle provided in Embodiment 1 of the present invention;

[0036] Figure 3 This is a schematic diagram of the steering angle detection sensor structure of a high-speed omnidirectional self-balancing vehicle provided in Embodiment 1 of the present invention;

[0037] Figure 4 This is a block diagram illustrating the control principle of a high-speed omnidirectional self-balancing vehicle provided in Embodiment 1 of the present invention.

[0038] Figure 5 This is a schematic diagram of the handrail structure of a high-speed omnidirectional self-balancing vehicle provided in Embodiment 1 of the present invention;

[0039] Figure 6This is another structural schematic diagram of a high-speed omnidirectional self-balancing vehicle provided in Embodiment 1 of the present invention;

[0040] Figure 7 This is a flowchart of a control method for a high-speed omnidirectional self-balancing vehicle provided in Embodiment 1 of the present invention;

[0041] Figure 8 This is a schematic diagram illustrating the tilting state analysis of a high-speed omnidirectional self-balancing vehicle provided in Embodiment 1 of the present invention;

[0042] Figure 9 The graph of the sin(θ) / cos(θ) function;

[0043] Figure 10 This is a schematic diagram illustrating the uniform motion state analysis of a high-speed omnidirectional self-balancing vehicle provided in Embodiment 1 of the present invention;

[0044] Figure 11 This is a schematic diagram illustrating another uniform motion state analysis of a high-speed omnidirectional self-balancing vehicle provided in Embodiment 1 of the present invention;

[0045] Figure 12 This is a schematic diagram illustrating the variable speed motion state analysis of a high-speed omnidirectional self-balancing vehicle provided in Embodiment 1 of the present invention;

[0046] Figure 13 This is a schematic diagram illustrating the motion state analysis of a high-speed omnidirectional self-balancing vehicle according to Embodiment 1 of the present invention.

[0047] In the diagram: 1. Vehicle body; 2. Human-machine input device; 3. Steering transmission; 4. Steering servo; 5. Steering angle detection sensor; 6. Front wheel; 7. Rear wheel; 8. Power module; 9. Integrated circuit control module; 10. Handrail. Detailed Implementation

[0048] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] Example 1

[0050] like Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, this embodiment proposes a high-speed omnidirectional self-balancing vehicle, which includes a vehicle body 1, a human-machine input device 2, at least one front wheel 6 disposed at the front of the vehicle body 1, at least one rear wheel 7 disposed at the rear of the vehicle body 1, a drive mechanism, a steering control mechanism, a power module 8 disposed at the bottom of the vehicle body 1, and an integrated circuit control module 9.

[0051] There is a preset distance between the front wheel 6 and the rear wheel 7, and the vehicle body 1 is provided with a standing area or seating area for personnel located between the front wheel 6 and the rear wheel 7. In this embodiment, "front and rear" refers to the forward and reverse directions in the high-speed (main) driving direction of the vehicle.

[0052] The human-machine input device 2 is used to acquire the user's operational intentions or commands. In this embodiment, pressure sensors are distributed front and rear. Their operation is as follows: when the user stands and shifts their weight forward, the pressure sensor reading on the front side is higher, causing the vehicle to accelerate forward. When the user shifts their weight backward, the pressure sensor reading on the rear side is higher, causing the vehicle to decelerate or begin reversing. It should be noted that the primary purpose of the human-machine input device 2 is to acquire the user's intentions and control the vehicle's forward and backward movement. Therefore, the human-machine input device 2 can take many forms and is not limited to pressure sensors.

[0053] Here are two more specific examples of human-computer input devices 2.

[0054] Example 1: The vehicle body 1 is flexibly connected to the front and rear wheels 7, allowing the rider to tilt the vehicle body 1 forward or backward relative to the ground by shifting their center of gravity. In this case, the tilt angle detection unit can be reused as the human-machine input device 2 to control the vehicle's forward / backward movement. When the vehicle body 1 tilts forward, the vehicle accelerates forward; when the vehicle body 1 tilts backward, the vehicle decelerates or reverses.

[0055] Example 2: A handrail is installed on vehicle body 1, and a wired electronic throttle is installed on the handrail. Alternatively, the vehicle can connect to wireless devices such as mobile phones and remote controls via wireless communication, allowing commands to be input wirelessly.

[0056] The drive mechanism connects the front wheel 6 and / or the rear wheel 7, and is used to drive at least one of the front wheel 6 and the rear wheel 7 to rotate. At least one of the front and rear wheels is driven by an electric motor, providing power for the vehicle's forward and backward movement. It can also provide power for lateral balance when the vehicle is stationary or at low speed. In this embodiment, the drive mechanism includes a drive motor connected to the active wheel, and the integrated circuit module includes a motor driver connected to the main control MCU. The drive motor is connected to the motor driver. The motor driver provides forward / reverse power to the wheel and obtains wheel speed / torque feedback values.

[0057] The front wheels 6 and rear wheels 7 are connected to a steering control mechanism, which controls the steering angle of the front wheels 6 and rear wheels 7. In this embodiment, the steering control mechanism includes a steering transmission 3 and a steering servo 4. The steering transmission 3 is rotatably mounted on the front or rear of the vehicle body 1. The front wheels 6 and rear wheels 7 are connected to the steering transmission 3. Gears, belts, chains, or cable devices are provided on the outer side of the steering transmission 3. The steering servo 4 is mounted on the vehicle body 1 and connected to the steering transmission 3 via gears, belts, chains, or cable devices. The integrated circuit control module 9 includes a steering controller connected to the main control MCU, and the steering controller is connected to the steering servo 4. The steering controller provides steering force to the wheels and obtains wheel steering angle feedback.

[0058] In this embodiment, at least one wheel uses a controllable steering structure. In this embodiment, the steering transmission 3 is a hollow turntable structure that connects the vehicle body 1 to the front and rear wheels 7. After connection, the wheels can rotate along the central axis of the steering wheel. The steering transmission 3 has gears on its exterior, which mesh with the gears on the steering servo 4, allowing the steering controller to control the steering angle of the wheels.

[0059] In this embodiment, the steering control mechanism also includes a steering angle detection sensor 5, which is installed on the transmission device or on the steering servo, and is used to detect the wheel steering angle.

[0060] Power module 8 supplies power to the entire vehicle. Integrated circuit control module 9 includes a main control MCU and a tilt sensor. The tilt sensor detects the tilt angle of the vehicle body 1. Human-machine input device 2, drive mechanism, steering control mechanism, and tilt sensor are all connected to the main control MCU. The tilt sensor consists of deformation detectors (strain gauges, pressure sensors, and distance sensors), or it can be composed of a six-axis / gravity sensor. Its main purpose is to obtain the tilt angle of the vehicle relative to the vertical direction.

[0061] In this embodiment of the self-balancing scooter, the front wheel 6 includes one wheel, and the rear wheel 7 includes one wheel. In another embodiment, the front wheel 6 includes two wheels symmetrically arranged on the left and right, and the rear wheel 7 includes one wheel, as shown below. Figure 6 As shown. The whole can include three or more wheels. The wheels are connected to the vehicle body 1 and are divided into two groups, distributed at the front and rear of the vehicle body 1. The wheels in each group are distributed to the left and right, so that the rider can tilt the vehicle body 1 to the left or right relative to the ground by shifting the center of gravity.

[0062] In this embodiment, as Figure 5 As shown, handrails can be further added to the present invention, making it easier for operators to keep the body tilt and the vehicle tilt in the same direction and angle, thus reducing the learning cost of vehicle operation.

[0063] like Figure 7 As shown, the control method for a high-speed omnidirectional self-balancing vehicle proposed in this embodiment specifically includes the following steps:

[0064] Step 1: The balance control cycle begins, and the tilt angle θ of the vehicle to the left or right is detected by the tilt angle detection sensor.

[0065] Step 2: Determine the vehicle balance control method based on the current vehicle speed, wheel steering angle, vehicle tilt angle, and user intent or command.

[0066] Vehicle balance control methods include:

[0067] Variable speed motion is suitable for situations where the vehicle speed is high and the wheel steering angle is small.

[0068] The simultaneous steering of the front and rear wheels (7 in total) during transmission is suitable for situations where the user does not need to adjust the direction of the vehicle.

[0069] The curvature motion mode with a constant wheel steering angle in variable speed driving is suitable for situations where the user needs to adjust the direction of the vehicle.

[0070] Uniform speed motion is suitable for situations where the vehicle speed is low and the wheel steering angle is large.

[0071] Uniform speed + variable speed motion is suitable for situations where the vehicle speed is low but still has a certain speed, and the vehicle tilts at a large angle, and is about to fall.

[0072] When determining the balance control method to use, user intent or commands should be given priority. For example, when the user is controlling the vehicle speed, uniform speed should be used as much as possible to avoid the user being surprised by sudden changes in motor speed. Also, when the user does not need to turn the vehicle around, curvature motion should be avoided as much as possible.

[0073] Step 3: Based on the determined vehicle balance control method and the corresponding control formula for the vehicle's center of gravity tilt angle θ, adjust the two parameters: wheel speed and wheel steering angle. This changes the vehicle's acceleration 'a' in the left and right directions, ultimately changing the vehicle's tilt angle θ in the left and right directions. After this step, you can directly enter a new control cycle, or you can choose to enter steps 4 and 5 to further enhance the vehicle's balance stability.

[0074] Step 4: Detect the vehicle tilt angle after balance adjustment, compare the adjusted vehicle tilt angle with the target tilt angle, and perform closed-loop control.

[0075] The purpose of this step is to examine the effectiveness of step 3. If the effectiveness of step 3 is higher than expected, the parameter values ​​of the control formula in step 3 are reduced to make the control smoother and avoid overshoot or repeated oscillations. If the effectiveness of step 3 is lower than expected, the parameter values ​​of the control formula in step 3 are increased to make the control faster and more effective and avoid crashes caused by control lag failing to suppress the continued increase in tilt angle.

[0076] Step 5: After completing the above steps, a new balance control cycle begins.

[0077] The following section uses a two-wheeled self-balancing scooter that simultaneously controls the steering of both the front and rear wheels as an example to explain the principle and control strategy of this embodiment:

[0078] Current two-wheeled vehicle balancing technology has revealed the following issues: the bicycle's balance performance does not primarily stem from the following two factors: 1. the gyroscopic effect of the wheels; 2. the wake effect of the front wheel. Even without these two effects, two-wheeled vehicles can still maintain relatively good self-balancing performance.

[0079] Therefore, excessively considering wheel drag distance or relying on gyroscopic effects to maintain vehicle balance in the design of two-wheeled vehicles is putting the cart before the horse. Thus, this invention differs from traditional two-wheeled vehicle design logic, disregarding gyroscopic control and the self-correcting effect caused by wheel drag distance. Instead, it uses acceleration adjustment to balance the forces for equilibrium control.

[0080] Because the wheels of this invention are distributed front and rear, it is relatively easy for personnel to adjust the center of gravity of the vehicle between the front and rear wheels 7, reducing the risk of tipping over in the front-to-back direction. Therefore, the force situation in the front-to-back direction is not considered, and only the influence of the force and acceleration components in the left-to-right direction is considered.

[0081] Consider the following dumping scenario:

[0082] like Figure 8 As shown, when the height of the vehicle's center of mass is H, the total mass is M, the acceleration due to gravity is g, and the angle of deviation from the vertical is θ, the acceleration of the center of mass is a. To maintain balance, the vehicle's center of mass needs to have a rightward acceleration.

[0083] The force equilibrium relationship is as follows: F = Mg*sin(θ) = M*a / cos(θ)

[0084] Therefore, the rightward acceleration component of the vehicle's center of gravity needs to reach a = g*sin(θ) / cos(θ) to maintain force balance at this point.

[0085] Furthermore, in reality, the vehicle is not tilted upon startup. Therefore, when this tilt is achieved, the center of gravity of the vehicle and its rider already has a rightward tilting velocity relative to the wheel contact point. At this point, the rightward velocity of the center of gravity can be considered higher than that of the wheel contact point. Therefore, the rightward acceleration component at the wheel contact point needs to reach a higher value to reduce the tilting velocity. Also, since the purpose of balance control during straight-line driving is to push the center of gravity back directly above the line connecting the front and rear wheels (7 points), the acceleration 'a' needs to be higher. That is, the acceleration of the center of gravity 'a' needs to be greater than g*sin(θ) / cos(θ).

[0086] like Figure 9 As shown, when θ approaches 0, the graph of sin(θ) / cos(θ) approximates a linear function with a slope of 1. However, in actual balance control, |θ| rarely exceeds 15°. Therefore, the target value 'a' can be simplified to a function linearly related to θ, i.e., a = k * θ, where k is an empirical coefficient.

[0087] To obtain the target value 'a', this invention proposes two motion methods to provide the required rightward acceleration for the overall center of mass of the vehicle and its rider. It should be noted that both motion methods have suitable applications. Either method can be used alone, or they can be used in combination.

[0088] ① Uniform motion and ② Variable motion. These two adjustment modes respectively refer to the following two control strategies.

[0089] ① Uniform motion refers to the motion of the wheel forward / backward without a sudden change in its velocity (velocity modulus). In this case, the rightward component of the acceleration mainly comes from the sudden change in the rightward velocity component caused by the change in the velocity direction (velocity vector).

[0090] ② Variable speed motion refers to a sudden change in the speed (velocity modulus) of the wheel rotating forward / backward. In this case, the rightward component of acceleration mainly comes from the sudden change in velocity component caused by the change in the speed (velocity modulus) of the wheel.

[0091] As will be pointed out later, uniform motion is mostly used for lateral balance at high speeds, while variable motion is mostly used for lateral balance at low speeds.

[0092] ① Uniform motion

[0093] Uniform motion 1, sudden change in wheel steering angle

[0094] This refers to a situation where the speed V of the vehicle's wheels remains constant, according to... Figure 10 Balance control is achieved by controlling the steering of the wheels. At this time, the steering angle ρ of the front and rear wheels 7 is changed, and the vehicle moves in translation.

[0095] When the wheels turn right, assume the modulus of the vehicle's velocity V does not change abruptly. The velocity of the vehicle's center of mass changes from V0 to V1, with a velocity change of δV. The time taken for the wheels to turn is δt, during which the rightward velocity component increases from 0 to δV*cos(ρ). That is, the rightward acceleration is a = δV*cos(ρ) / δt.

[0096] More generally, the initial steering angle doesn't necessarily start at 0 degrees. Assuming the wheel speed V doesn't change abruptly, the rightward acceleration at a given moment can be expressed by the following formula: where ρ is the current wheel angle, and ω = δρ / δt is the rotational speed of the wheel turning to the right.

[0097] Lim(δt→0):a=V*[sin(ρ+δρ)-sinρ] / δt

[0098] a=V*ω*cosρ

[0099] Combining the above text, a = k * θ

[0100] Therefore, the control strategy at this time can be obtained as follows:

[0101] θ=V*cosρ*ω / k

[0102] Where k is an empirical constant, θ is the right tilt angle of the vehicle and the person, and V is the current vehicle speed.

[0103] Calculations show that when a vehicle or pedestrian is tilted, adjusting the balance by steering requires both speeds V and ω to be relatively high, and the value ρ to be near 0° for optimal results. Conversely, when both V and ω are relatively low, and the value ρ is near 90°, effective balance adjustment is not possible.

[0104] 2. The wheels move at a constant speed without a sudden change in steering angle, such as... Figure 11 As shown:

[0105] This refers to a situation where the vehicle's wheel speed V remains constant, and the steering angle ρ of the front and rear wheels also remains constant. In this case, the vehicle undergoes curvature motion, and the rightward acceleration mainly comes from the positive rightward component of the centripetal acceleration.

[0106] When the total center of mass M of the vehicle and the person turns to the right with radius R and linear velocity V, the output rightward acceleration can be continuously generated without any control changes.

[0107] a = cos(ρcenter of mass) * (V² / R)

[0108] Where 'a' is the right-hand component of the centripetal acceleration. ρ_center of mass is the angle between the line connecting the centers of rotation of the center of mass and the rightward direction. V and R are the linear velocity of the center of mass and the radius of rotation of the center of mass, respectively.

[0109] The control strategy at this point can be expressed as follows: The control method formula is as follows:

[0110] θ = cos(ρ_centroid) * V² / (R * k)

[0111] The centroids V, R, and ρ in the above formula can be obtained by performing trigonometric function calculations based on the distance L between the front and rear wheels 7, the steering angle ρ1 of the front wheel 6, the deflection angle ρ2 of the rear wheel 7, and the rotational speed V of the front wheel 6. While the calculations are complex, the derivation logic is self-evident and will not be elaborated upon here.

[0112] ② Variable speed motion: Because the motor wheel in this invention differs significantly from traditional bicycle / motorcycle wheels, it can precisely and sensitively control speed, or rotate in the opposite direction and provide reverse power. Therefore, variable speed motion balance can be achieved.

[0113] Variable speed motion 1,

[0114] When both front and rear wheels maintain a steering angle ρ, a sudden change in wheel speed V will result in a wheel acceleration a_wheel = (V1-V0) / δt, and the rightward acceleration component of wheel a is the required rightward acceleration a of the entire vehicle.

[0115] like Figure 12 As shown, the acceleration in the right direction at this time

[0116] a = a_wheel * sinρ

[0117] Furthermore, the relationship between the vehicle's rightward acceleration *a* and the vehicle's center of gravity tilt angle, derived earlier, is *a* = *k*θ.

[0118] The control formula used at this time can be derived as follows:

[0119] θ = a_wheel * sinρ / k

[0120] At this point, controlling the wheel speed V is sufficient to maintain the vehicle's lateral balance. It's important to note that when ρ is around 90°, controlling lateral balance through gear shifting is most effective. However, at this speed, there is almost no velocity in the forward direction. Therefore, gear shifting is primarily used for lateral balance at low speeds.

[0121] It should be noted that in extreme cases, ρ = 90° and sinρ = 1. In this case, the vehicle V will not cause the vehicle to move forward or backward, but will only maintain balance in the left and right directions.

[0122] Variable Speed ​​Motion 2

[0123] Transmission can also be balanced by the steering angle ρ of just one wheel. For example... Figure 13 As shown, at this moment, the rightward acceleration of the vehicle's center of gravity is a = 0.5 * a_wheel.

[0124] The control formula used at this time can be derived as θ = 0.5 * a_wheel / k;

[0125] At this time, controlling the change of vehicle V can control the vehicle to rotate around the non-steering wheel as the center.

[0126] It should be noted that both uniform motion and variable motion control methods can be implemented by controlling a single vehicle or by controlling the front and rear wheels simultaneously. Therefore, the minimum hardware requirements for balance control of a vehicle are: to control the steering of at least one wheel and to control the speed of at least one wheel.

[0127] Furthermore, uniform motion and variable motion do not conflict and can be used in combination. At this point, the vehicle's lateral acceleration is the sum of the acceleration values ​​calculated by the two control methods.

[0128] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A control method for a high-speed omnidirectional self-balancing vehicle, characterized in that, The self-balancing scooter includes a vehicle body, a human-machine input device, at least one front wheel located at the front of the vehicle body, at least one rear wheel located at the rear of the vehicle body, a drive mechanism, a steering control mechanism, a power module located at the bottom of the vehicle body, and an integrated circuit control module. The front and rear wheels have a preset distance between them. The vehicle body is provided with a standing area or seating area for personnel located between the front and rear wheels. The human-machine input device is used to acquire user operation intentions or commands. The drive mechanism is connected to the front and / or rear wheels and is used to drive at least one of the front and rear wheels to rotate. The front and rear wheels are connected to a steering control mechanism, which is used to control the steering angle of the front and rear wheels. The power module is used to supply power to the entire vehicle. The integrated circuit control module includes a main control MCU and a tilt angle detection sensor. The tilt angle detection sensor is used to detect the tilt angle of the vehicle body. The human-machine input device, drive mechanism, steering control mechanism, and tilt angle detection sensor are all connected to the main control MCU. The control method includes: The balance control cycle begins, and the tilt angle θ of the vehicle to the left or right is detected by the tilt angle detection sensor; The vehicle balance control method is determined based on the current vehicle speed, wheel steering angle, vehicle tilt angle, and user intent or command. Based on the determined vehicle balance control method and the corresponding control relationship formula of the vehicle center of gravity tilt angle θ, the two parameters of wheel speed and wheel steering angle are adjusted to change the acceleration a in the left and right directions of the vehicle, and finally to change the tilt angle θ in the left and right directions of the vehicle. The vehicle tilt angle after balance adjustment is detected, and the adjusted vehicle tilt angle is compared with the target tilt angle for closed-loop control. After the above steps are completed, a new balance control cycle begins.

2. The control method for a high-speed omnidirectional self-balancing vehicle according to claim 1, characterized in that, The vehicle balance control method includes: Variable speed motion is suitable for situations where the vehicle speed is high and the wheel steering angle is small. The simultaneous steering of the front and rear wheels during gear shifting is suitable for situations where the user does not need to adjust the direction of the vehicle. The curvature motion mode with a constant wheel steering angle in variable speed driving is suitable for situations where the user needs to adjust the direction of the vehicle. Uniform speed motion is suitable for situations where the vehicle speed is low and the wheel steering angle is large. Uniform speed + variable speed motion is suitable for situations where the vehicle speed is low but still has a certain speed, and the vehicle is tilted and about to fall. When determining the balance control method to use, user intent or instructions should be given priority.

3. The control method for a high-speed omnidirectional self-balancing vehicle according to claim 1, characterized in that, The human-machine input device includes a pressure sensor installed in the standing area, a tilt sensor for detecting the tilt angle of the vehicle body, a manual input device, and a remote wireless device.

4. The control method for a high-speed omnidirectional self-balancing vehicle according to claim 1, characterized in that, The drive mechanism includes a drive motor connected to the drive wheel, and the integrated circuit control module includes a motor driver connected to the main control MCU, and the drive motor is connected to the motor driver.

5. The control method for a high-speed omnidirectional self-balancing vehicle according to claim 1, characterized in that, The steering control mechanism includes a steering transmission and a steering servo. The steering transmission is rotatably mounted on the front or rear of the vehicle body. The front and rear wheels are connected to the steering transmission. Gears, belts, chains, or cable devices are provided on the outer side of the steering transmission. The steering servo is mounted on the vehicle body and connected to the steering transmission via gears, belts, chains, or cable devices. The integrated circuit control module includes a steering controller connected to the main control MCU. The steering controller is connected to the steering servo.

6. The control method for a high-speed omnidirectional self-balancing vehicle according to claim 1, characterized in that, The steering control mechanism also includes a steering angle detection sensor, which is mounted on the transmission device or the steering servo, and is used to detect the wheel steering angle.

7. The control method for a high-speed omnidirectional self-balancing vehicle according to claim 1, characterized in that, The front wheel includes a single wheel, and the rear wheel includes a single wheel.

8. The control method for a high-speed omnidirectional self-balancing vehicle according to claim 1, characterized in that, Both the front and rear wheels consist of a single wheel with a certain width, or a set of wheels arranged symmetrically on the left and right.

9. The control method for a high-speed omnidirectional self-balancing vehicle according to claim 1, characterized in that, The vehicle body is equipped with handrails.

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