A Vector Torque Balance Control Method for a High-Speed Unmanned Bicycle

Abstract

The present invention relates to a vector torque balance control method for a high-speed unmanned bicycle. The central processing unit controls the balance system by using an adaptive control method according to the bicycle speed, inclination angle, and momentum wheel speed periodically collected by a six-axis sensor to maintain the balance of the bicycle. The six-axis sensor is used to periodically collect the bicycle speed, inclination angle, and momentum wheel speed and transmit the collected information to the central processing unit. The balance system includes a balance motor, a steering servo, an inclination servo, and a momentum wheel to provide a balance torque. The present invention solves the problems that the current balance bicycles are limited to dynamic low-speed balance and the balance device is too large in volume, and realizes the high-speed and stable movement and static and dynamic balance of the unmanned bicycle.

Description

Technical Field

[0001] The present invention relates to a vector torque balance control method for a high-speed unmanned bicycle, belonging to the balance method of two-wheeled bicycles and involving the field of automatic control. Background Art

[0002] A bicycle is a two-wheeled small land vehicle and also the most common means of transportation in people's daily lives. In 2019, the social ownership of bicycles in China has nearly reached 400 million, ranking first in the world. The structure of a bicycle is simple. After its speed reaches a certain level, it is very easy to achieve stable control artificially. However, due to the complex mechanical model of the bicycle and only two force points, the complex mechanical model brings great difficulties to the solution of its balance problem, and its related theoretical models and control systems have received extensive attention and research from many scholars.

[0003] Nowadays, with the development of artificial intelligence and unmanned driving technology, the balance of two-wheeled intelligent transportation tools has become a classic and academically valuable problem in the field of control. Compared with the coaxial system, the two-wheeled non-coaxial system has the characteristics of static balance, small floor area, strong passability and high flexibility. By building a motion control module for a high-speed unmanned bicycle, it can be applied to narrow and crowded roads to replace four-wheeled vehicles to perform related tasks. In addition, the high-speed unmanned bicycle can further be applied to experimental research such as motion control, path planning, and unmanned transportation, which has positive significance for experimental verification in the fields of control theory and artificial intelligence.

[0004] Currently, most bicycle balance systems process the attitude angle of the bicycle through a single-chip microcomputer, and then control the front of the vehicle through a servo to achieve dynamic balance and movement control of the bicycle. However, in a static state, in a more complex environment or at a high speed, the above control methods are difficult to achieve stable balance. Summary of the Invention

[0005] (1) Technical Problems to be Solved

[0006] In view of the deficiencies of the prior art, the present invention provides a vector torque balance control method for a high-speed unmanned bicycle, which has the characteristics of dynamic and static balance, stable high-speed steering, strong anti-interference ability, strong fault tolerance and expandability.

[0007] (2) Technical Solutions

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] A vector torque balance control method for a high-speed unmanned bicycle, characterized in that the control method is based on including a central processing unit, a six-axis sensor, a balance system, a power system, a power supply system, a connection system, and an information interaction system;

[0010] The central processing unit is electrically connected to the six-axis sensor and the balancing system, and is configured to process the body state information obtained by the six-axis sensor and transmit the processed control signal to the balancing system to control the bicycle in real time;

[0011] The six-axis sensor is configured to periodically collect the bicycle speed, inclination angle, and momentum wheel speed, and transmit the collected information to the central processing unit;

[0012] The balancing system includes a balancing motor, a steering servo, an inclination servo, and a momentum wheel; the balancing motor is fixed to the exact center below the seat by screws and nuts and is connected to the momentum wheel; the steering servo is coaxially fixed to the front wheel shaft; the inclination servo drives the momentum wheel to deflect through a transmission gear. The balancing system is configured to maintain the balance of the vehicle body during the running of the bicycle; the vehicle body balance is mainly controlled by the momentum wheel controlled by the balancing motor and the inclination servo; the balancing motor generates an adjustable rotational torque by controlling the speed of the momentum wheel; according to the body angle and servo angle measured by the six-axis sensor, under the control of the inclination servo, the momentum wheel forms an inclination angle with the vertical plane of the vehicle body to assist in balancing and steering, realizing vector torque control.

[0013] The power system includes a reduction motor and a transmission structure, and is configured to drive the bicycle to move forward or backward; the reduction motor measures the motor speed by collecting the pulse signal of the motor encoder.

[0014] The power supply system converts the battery power into a stable reference voltage to supply power to the central processing unit, the balancing device, and the detection device.

[0015] The connection system includes the installation and fixation methods among various parts of the vehicle body main body, the steering servo, the inclination servo, the momentum motor, and the momentum wheel.

[0016] The information interaction system includes a display and a communication interface; the display is configured to display the system parameter information and set the system parameters; the communication interface is configured to connect the six-axis sensor, the central processing unit, the motor drive board, and the voltage sampling circuit, and is used to realize remote communication with a wireless communication device.

[0017] As a further optimization scheme of the vector torque balance control method for a high-speed unmanned bicycle according to the present invention, in the control device, in addition to being used to control the steering of the bicycle, the steering servo of the connection system is further used to assist in changing the inclination angle of the vehicle body when the turning radius of the bicycle is too small, so as to improve the cornering performance.

[0018] As a further optimization scheme of the vector torque balance control method for a high-speed unmanned bicycle according to the present invention, the control method includes the following steps:

[0019] Press the power switch to start the system. Observe whether the parameters of each part of the system and the power supply voltage are normal through the screen, and at the same time set the control parameters by yourself through the screen.

[0020] Detect the inclination angle θ and the inclination angular velocity ω of the bicycle body through a six-axis sensor, obtain the rear wheel speed v1, the front axle servo angle α, and the momentum motor speed v2 according to the value of the rear wheel encoder. Through the established bicycle balance model, input the above parameters, and output to obtain the control signal, that is, the output value of the momentum motor is υ, the steering angle α of the steering servo, and the inclination angle γ of the inclination servo.

[0021] By controlling the output value υ of the momentum motor, the steering angle α of the steering servo, and the inclination angle γ of the inclination servo, control the balance motor and the inclination motor to drive the momentum wheel, and use the rotation torque of the momentum wheel to achieve the self-balanced state of the bicycle, and achieve auxiliary balance and steering stability by controlling the steering servo.

[0022] As a further optimization scheme of the vector torque balance control method for a high-speed unmanned bicycle of the present invention, the bicycle balance model and the control law have the following forms:

[0023] υ = U1 + U2

[0024]

[0025]

[0026]

[0027]

[0028] Among them, υ represents the output value of the momentum motor, K p 、K i 、K d are PID parameters, represents the current body tilt angle, represents the balance angle, θ represents the inclination angle of the bicycle body, ω represents the inclination angular velocity, v1 represents the rear wheel speed, α represents the front axle servo angle, v2 represents the momentum motor speed, β represents the front wheel servo steering angle, and γ represents the inclination servo angle.

[0029] (III) Beneficial effects

[0030] Compared with the prior art, the present invention provides a vector torque balance control method for a high-speed unmanned bicycle, which has the following beneficial effects:

[0031] 1. Compared with the traditional bicycle self-balancing system, the present invention realizes the self-balancing of the bicycle through the combined action of the balancing motor, the directional servo and the tilt servo. In the case of turning or interference, the direction of the momentum torque can be adjusted by the tilt servo, making the control more efficient and stable, solving the problem that most current bicycle balancing systems can only achieve dynamic balancing and the balancing device is too large.

[0032] 2. Compared with the traditional bicycle self-balancing system, the present invention can maintain the stability of the bicycle's steering at high speed, and can be used in more scenarios such as high-speed cornering, bicycle racing, etc.

[0033] 3. The present invention has strong environmental universality and is more suitable for narrow urban streets, mountainous areas and environments with more gravel obstacles. The system-related control parameters can be dynamically set through the touch screen, and the system balance parameters can be adjusted in real time according to the environment, which improves the flexibility of the system and enhances the system robustness and anti-interference.

[0034] 4. The present invention has strong expansibility and developability. The present invention provides an interface circuit, which expands the use scenarios and functionality of the system by connecting external cameras, GPS and other devices, and provides more application possibilities, such as automatic parking, automatic vehicle owner search, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the overall structure of the system of the present invention;

[0036] Figure 2 It is a schematic diagram of the internal structure of the system of the present invention;

[0037] Figure 3 is a partial schematic diagram of a balancing motor of the system of the present invention;

[0038] Figure 4 It is a schematic diagram of the overall working unit of the present invention;

[0039] Figure 5 It is a work flow chart of the present invention;

[0040] In the figure, 1-front wheel steering servo, 2-display, 3-front wheel shaft, 4-six-axis sensor, 5-central processing unit, 6-momentum wheel, 7-rear wheel reduction motor, 8-momentum wheel motor, 9-front wheel, 10-rear wheel, 11-bicycle body, 12-rear wheel transmission chain, 13-battery, 14-host computer, 15, 15.1, 15.2-tilt steering gear. DETAILED DESCRIPTION

[0041] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments, but the implementation manner of the present invention is not limited thereto.

[0042] 1. Detailed elaboration of the technical solution of the present invention:

[0043] As Figure 1 shown, a vector torque balance control method for a high-speed unmanned bicycle is composed of a front-wheel steering servo 1, a display 2, a front-wheel rotating shaft 3, a six-axis sensor 4, a central processing unit 5, a momentum wheel 6, a rear-wheel reduction motor 7, a momentum-wheel motor 8, a front wheel 9, a rear wheel 10, a bicycle body 11, a rear-wheel drive chain 12, a battery 13, a host computer software 14, and a momentum-wheel inclination steering mechanism 15. As Figure 2 shown, the battery 13 is integrated with the central processing unit 5. The front-wheel steering servo 1 is connected to the front-wheel rotating shaft 3 to control the direction of the front of the bicycle body 11. The central processing unit 5 and the six-axis sensor 4 integrated module are installed in a suitable area inside the vehicle body parallel to the horizontal plane, and the battery supplies power to the entire system through an external switch.

[0044] The balance system includes a momentum-wheel motor 8, a front-wheel steering servo 1, and a momentum-wheel inclination gear 15. The front-wheel steering servo 1 is coaxially fixed with the front-wheel rotating shaft 3. The momentum-wheel motor 8 is fixed under the seat by screws and nuts. The momentum-wheel motor 8 is connected to the momentum wheel 6 to provide left and right balance forces. The front-wheel steering servo 1 is installed on the front-wheel rotating shaft to control the vehicle body steering and assist in balancing; the steering gear controls the inclination angle of the momentum wheel 6 through an inclination servo;

[0045] The rear-wheel drive system includes a reduction motor 7 and a transmission structure 12 for driving the bicycle forward or backward;

[0046] The momentum-wheel inclination steering mechanism 15 includes an inclination steering servo 15.1 and a transmission gear 15.2;

[0047] The reduction motor includes an encoder to collect the pulse signal of the motor encoder to measure the motor speed;

[0048] The power supply system is used to convert the voltage of the battery 13 into a stable reference voltage to supply power to the central processing unit 5, the balance system, and the detection system;

[0049] The present invention provides a vector torque balance control method for a high-speed unmanned bicycle, adopting the following control method:

[0050] The six-axis sensor detects the current inclination angle θ, tilt angular velocity ω of the bicycle body 11, obtains the rear-wheel speed υ1 according to the value of the rear-wheel encoder, the rotation angle α of the front-axis steering servo 1, and the rotation speed υ2 of the momentum motor 8, and calculates the target rotation speed υ of the momentum motor 8 through the following formula:

[0051]

[0052] υ = U1 + U2

[0053] Where represents the default balance angle of the bicycle body, which can be changed according to the body condition by oneself. represents the current tilt angle of the bicycle body, and υ represents the current rotational speed output value of the momentum motor.

[0054] To achieve stable turning and large-angle turning of the bicycle, the steering angle β of the steering gear 1 can be calculated by the following formula:

[0055]

[0056] To better control the turning performance of the bicycle, the default balance angle of the bicycle body is dynamically updated by the following formula:

[0057]

[0058] Vector control of the bicycle can be achieved by controlling the tilt angle of the momentum wheel. The steering angle γ of the tilt steering gear can be calculated by the following formula:

[0059]

[0060] It should also be noted that the variables not described in the above formulas can be set according to the environment and the condition of the bicycle by oneself;

[0061] The stable operation process of the bicycle and the correct operation steps adopted by the user are as follows:

[0062] a. Press the power switch and check whether the module initialization is completed and whether the power supply voltage is normal through the prompt information on the display;

[0063] b. If it is necessary to change the system balance parameters, the system default balance model parameters can be changed by entering the parameter setting interface through the display or the upper computer;

[0064] c. Start the system, swing the bicycle body left and right, and observe whether the data of the six-axis sensor displayed on the display or the upper computer is normal;

[0065] d. The six-axis sensor detects the tilt angle θ, tilt angular velocity ω of the bicycle body, obtains the rear wheel speed v1 according to the value of the rear wheel encoder, the steering angle α of the front axle steering gear, and the rotational speed v2 of the momentum motor. Through the established bicycle balance model, input the above parameters, and the output obtains the output value v of the momentum motor, the steering angle β of the steering gear, and the steering angle γ of the tilt steering gear;

[0066] e. By controlling the output value υ of the balance motor, the steering angle β of the front wheel steering gear, and the steering angle γ of the tilt steering gear, keep the bicycle body in a balanced state, that is, achieve self-balancing;

[0067] f. When external factors change, resulting in changes in the vehicle body mass distribution or structure, relevant control parameters need to be changed through the display or the host computer. until the self-balancing of the bicycle body is re-established;

[0068] g. Through steps a - f, the dynamic and static balance of the bicycle body under normal circumstances can be achieved. At the same time, the bicycle can be controlled by the host computer to move forward, backward, turn, accelerate, and decelerate in a driverless state. The bicycle can also achieve autonomous driving through external cameras and GPS.

Claims

1. A vector torque balance control method for a high-speed unmanned bicycle, characterized in that, The control method is based on a system including a central processing unit, a six-axis sensor, a balance system, a power system, a power supply system, a connection system, and an information interaction system; The central processing unit is electrically connected to the six-axis sensor and the balance system, and is configured to process the body state information obtained through the six-axis sensor and transmit the processed control signal to the balance system to control the bicycle in real time; The six-axis sensor is configured to periodically collect the bicycle speed, inclination angle, and momentum wheel speed, and transmit the collected information to the central processing unit; The balance system includes a balance motor, a steering servo, an inclination servo, and a momentum wheel; the balance motor is fixed to the exact center under the seat by screws and nuts and is connected to the momentum wheel; the steering servo is coaxially fixed to the front wheel shaft; the inclination servo drives the momentum wheel to deflect through a transmission gear; the balance system is configured to maintain the balance of the bicycle body during the bicycle's movement; the balance of the bicycle body is mainly controlled by the momentum wheel controlled by the balance motor and the inclination servo; The balance motor generates an adjustable rotational torque by controlling the speed of the momentum wheel; according to the body angle and servo angle measured by the six-axis sensor, under the control of the inclination servo, the momentum wheel forms an inclination angle with the vertical plane of the bicycle body, which is used to assist in balance and steering to achieve vector torque control; in addition to controlling the steering of the bicycle, the steering servo is also used to assist in changing the inclination angle of the bicycle body when the turning radius of the bicycle is too small to improve the cornering performance; The power system includes a reduction motor and a transmission structure, and is configured to drive the bicycle forward or backward; the reduction motor measures the motor speed by collecting the pulse signal of the motor encoder; The power supply system converts the battery power into a stable reference voltage to supply power to the central processing unit, the balance system, and the detection device; The connection system includes the installation and fixation methods between the various parts of the bicycle body, the steering servo, the inclination servo, the momentum motor, and the momentum wheel; The information interaction system includes a display and a communication interface; the display is configured to display the system parameter information and set the system parameters; the communication interface is configured to connect the six-axis sensor, the central processing unit, the motor drive board, and the voltage sampling circuit to achieve remote communication with a wireless communication device; The control method includes the following steps: Press the power switch to start the system, observe through the screen whether the parameters of each part of the system and the power supply voltage are normal, and set the control parameters through the screen by yourself at the same time; Detect the inclination angle of the bicycle body through a six-axis sensor , the tilt angular velocity , obtain the rear wheel speed according to the value of the rear wheel encoder , the steering angle of the front axle steering servo , the rotational speed of the momentum motor , through the established bicycle balance model, input the above parameters, and output to obtain a control signal, that is, the output value of the momentum motor is , the steering angle of the front axle steering servo and the steering angle of the inclination angle servo ; By controlling the output value of the momentum motor , the steering angle of the front axle steering servo and the steering angle of the tilt servo , the balance motor and the tilt motor are controlled to drive the momentum wheel. By using the rotational torque of the momentum wheel, the self-balanced state of the bicycle is achieved, and the auxiliary balance and steering stability are realized by controlling the steering servo.

2. The vector torque balance control method of a high-speed unmanned bicycle according to claim 1, characterized in that Adjust the output of the momentum motor of the bicycle through PID control to adjust the inclination angle of the bicycle body and the speeds of the front and rear wheels of the bicycle, so as to achieve the balanced and high-speed operation of the unmanned bicycle.

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