Control method for narrow-body vehicle based on control moment gyro

Abstract

The present application relates to a kind of narrow body vehicle balance control method based on control moment gyro, belong to narrow body vehicle active roll control system field.The dynamics equation of control moment gyro is established, the active roll dynamics model of narrow body vehicle is calculated to obtain the roll angle error and roll angular velocity error of vehicle, then the active roll controller is designed using sliding mode control method to control the roll angle error and roll angular velocity error, and the rotational angular velocity of control moment gyro frame is obtained;Finally, the control moment gyro on narrow body vehicle is adjusted in real time, and vehicle balance is realized.The vehicle roll scheme in the present application uses control moment gyro device, with high control precision, fast response speed, and independent of suspension system, can realize greater balance torque.By controlling the frame angular velocity of control moment gyro, the dynamic balance of narrow body vehicle when steering can be realized, to assist the safe steering of driver.

Description

Technical Field

[0001] This invention belongs to the field of active roll control systems for narrow-body vehicles, and relates to a balance control method for narrow-body vehicles based on a control moment gyroscope. Background Technology

[0002] In recent years, with the annual increase in car ownership, a series of problems such as urban traffic congestion, parking difficulties, high energy consumption, and serious environmental pollution urgently need to be addressed. Developing narrow-body electric vehicles for 1-2 people for urban transportation is a highly promising solution. However, due to their unique design—narrow body and relatively high center of gravity—these vehicles are prone to rollover when turning, seriously threatening the lives of drivers and passengers. Active roll control systems, by precisely controlling the vehicle's reasonable tilt towards the inside of the curve, fully utilize the center of gravity effect to maintain vehicle balance, potentially enabling safe steering for the driver. Most existing active roll solutions are improvements on the suspension system, causing the vehicle to tilt during steering. However, these solutions are structurally complex, and due to the integration of roll with the suspension system, the roll response hysteresis caused by suspension damping forces must be considered during control, resulting in high energy consumption.

[0003] A control moment gyroscope (CMM) is a torque amplification device with a short response time and high efficiency. Utilizing the law of conservation of angular momentum, it generates gyroscopic torque as output by changing the direction of the flywheel's angular momentum through frame rotation, thereby achieving attitude control of the controlled system. Compared to existing active roll control schemes, the CMM achieves balance through inertial control, offering high control precision, fast response, and independence from the suspension system. It can achieve a larger balancing torque, making it suitable for active roll control in narrow-body vehicles and beneficial for maintaining vehicle cornering balance. Current research on active roll control schemes largely focuses on suspension system improvements and integration, neglecting the mutual influence between the suspension and roll. Meanwhile, research on CMMs is concentrated in aerospace and two-wheeled vehicle fields, with limited application in active roll control. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a narrow-body vehicle balance control method based on a control moment gyroscope, which can actively control the vehicle's roll when it is turning, thereby achieving vehicle steering balance and assisting the driver in safe steering.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A method for balance control of narrow-body vehicles based on control moment gyroscopes includes:

[0007] Step S1: Establish the dynamic equations of the control moment gyroscope and the active roll dynamic model of the narrow-body vehicle;

[0008] Step S2: Based on the vehicle roll dynamics model obtained in step S1, calculate the vehicle roll angle error and roll angular velocity error.

[0009] Step S3: Design an active tilt controller using the sliding mode control method to control the tilt angle error and tilt angular velocity error calculated in step S2, and obtain the rotational angular velocity of the control moment gyroscope frame.

[0010] Step S4: Using the active tilt controller designed in step S3, the control torque gyroscope on the narrow-body vehicle is adjusted in real time to achieve vehicle balance.

[0011] The beneficial effects of this invention are as follows:

[0012] The vehicle roll control scheme in this invention employs an opposed control torque gyroscope device, which has high control precision, fast response speed, and is independent of the suspension system, enabling it to achieve a larger balance torque.

[0013] The active roll controller based on sliding mode theory designed in this invention adjusts the roll posture of the vehicle in real time when turning by controlling the frame angular velocity of the control moment gyroscope, thereby achieving dynamic balance when turning narrow-body vehicles and assisting the driver in safe steering.

[0014] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0015] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0016] Figure 1 This is a flowchart of a narrow-body vehicle balance control method based on a control torque gyroscope proposed in this invention;

[0017] Figure 2 A simplified structural diagram of a narrow-body vehicle;

[0018] Figure 3 Force diagram for controlling the torque gyroscope;

[0019] Figure 4 This is a schematic diagram of active vehicle tilting.

[0020] Figure 5 This is a block diagram of active roll control based on the sliding mode method.

[0021] Reference numerals: 1. Vehicle body; 2. Tire; 3. Control torque gyroscope; 4. Rotor motor; 5. Rotor; 6. Frame motor; 7. Gyroscope frame. Detailed Implementation

[0022] The following specific examples 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. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0023] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0024] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0025] Please see Figure 1 This describes a method for balancing narrow-body vehicles based on a control moment gyroscope, comprising the following steps:

[0026] Step S1: Establish the dynamic equations of the control moment gyroscope and the active roll dynamic model of the narrow-body vehicle.

[0027] like Figure 2 As shown, the structure of the narrow-body vehicle mainly includes components such as the frame 1, tires 2, gyroscope frames 7, frame motors 6, and rotor motors 4. Two control torque gyroscopes 3 are arranged in an opposing configuration, each fixed in a torque gyroscope chamber by two universal torque gyroscope frames 7. The torque gyroscope chambers are connected to the frame 1. The two frame motors 6 adjust the two torque gyroscope frames 7 to generate angles of the same magnitude but opposite directions. Two rotor motors 4 control two rotors 5 to move at angular velocities of the same magnitude but in opposite directions. It rotates on its own axis.

[0028] The control torque gyroscope 3 is subjected to forces as follows Figure 3 As shown, taking a single control torque gyroscope 3 as an example for analysis, when the motor control frame 7 causes the gyroscope rotor 5 to generate a precession angular velocity... The control torque gyroscope 3 will generate a force along the gyroscope. x Precession torque in the axial direction:

[0029] (1)

[0030] In the formula, I g Let be the moment of inertia of the gyroscope rotor 5.

[0031] When the control torque gyroscope 3 rotates to the angle α At point 1, it will cause a circumference around the vehicle body. x shaft and z The two torques of the shaft:

[0032] (2)

[0033] (3)

[0034] From formulas (2) and (3), it can be seen that as the rotational speed of the gyroscope rotor increases... The increase of its precession angular velocity The increase in size affects the vehicle body. x The effective torque on the shaft gradually increases. In practical operation, considering the stability of the gyroscope and the structure of the controller, the rotational speed of the gyroscope rotor 5 is kept constant at a fixed speed to generate a stable effective torque. The precession angular velocity of the gyroscope frame is controlled by the motor 6. The size is used to achieve vehicle body balance.

[0035] To ensure that the moment gyroscope 3 acts in the direction of the vehicle's tilting motion, the two moment gyroscopes 3 are arranged opposite each other. At this time, in the vehicle body... z The torques generated by the shafts cancel each other out. x The effective torque on the axis is the sum of the torques of the two torque gyroscopes 3, expressed as:

[0036] (4)

[0037] In the formula, The magnitude of the precession angular velocity of the two gyroscope frames.

[0038] The vehicle model is simplified, with the following assumptions: First, the vehicle body and control moment gyroscope 3 are multiple rigid entities; second, tire 2 only experiences rolling friction with the ground; third, the vehicle actively tilts to the right. The following assumptions are established: Figure 4 The vehicle active roll dynamics model shown is as follows:

[0039] (5)

[0040] In the formula, m The total mass of the vehicle; I x For vehicles to bypass x Moment of inertia of the shaft; φ This refers to the vehicle's roll angle; F y This refers to the lateral force of the tire; h The height of the center of mass.

[0041] Define the control inputs for the vehicle roll system model The state variables are Assuming angle If the value is small, then the system equation is:

[0042] (6)

[0043] Figure 5 The active roll control block diagram is shown. The roll rate error and roll angle error of the narrow-body vehicle are calculated. A sliding mode control method is used to design a controller to control the control moment gyroscope installed on the narrow-body vehicle, thereby obtaining the rotational angular velocity of the control moment gyroscope frame 7. The advance torque is output by the control moment gyroscope 3. T g To maintain the dynamic balance of narrow-body vehicles.

[0044] Step S2: Based on the vehicle roll dynamics model obtained in step S1, calculate the vehicle roll angle error and roll angular velocity error.

[0045] According to the vehicle roll dynamics model (5), when the vehicle is in a steering balance state, the roll angular acceleration and lateral acceleration are both zero. At this time, the gyro precession torque is zero, and the vehicle lateral force can be expressed as:

[0046] (7)

[0047] The desired vehicle roll angle is

[0048] (8)

[0049] In the formula, v For vehicle speed, The desired yaw rate of the vehicle is obtained based on an ideal linear two-degree-of-freedom model:

[0050] (9)

[0051] In the formula, μ The road surface adhesion coefficient, L This refers to the vehicle's wheelbase. δ f This refers to the steering angle of the front wheels.

[0052] Based on the desired roll angle obtained from equation (8) and the actual measured roll angle, the roll angle error is calculated, i.e.:

[0053] (10)

[0054] In the formula, φ This indicates the actual roll angle of the vehicle as measured.

[0055] Similarly, the roll rate error can be expressed as:

[0056] (11)

[0057] In the formula, This indicates the vehicle's desired roll rate. This indicates the vehicle's actual roll rate.

[0058] Step S3: Design an active roll controller using the sliding mode control method to control the roll angle error and roll angular velocity error calculated in step S2, thereby obtaining the precession angular velocity of the control moment gyroscope frame. ;

[0059] The designed sliding surface s is

[0060] (12)

[0061] In the formula, c is a constant and satisfies the Hurwitz condition, i.e., c > 0.

[0062] To ensure the system quickly approaches the sliding surface, the exponential reaching law is adopted as the sliding surface reaching law:

[0063] (13)

[0064] In the formula, This indicates the approach velocity to the sliding surface. k This represents the control gain, and all values ​​are constant.

[0065] To reduce system chattering, a saturation function is used instead of the sign function in equation (13), resulting in the control law:

[0066] (14)

[0067] By applying sliding mode control to the vehicle roll angle error and roll rate error, the control quantity is obtained, namely the precession angular velocity of the control moment gyroscope frame. .

[0068] Step S4: Using the active tilt controller designed in step S3, the control torque gyroscope 3 on the narrow-body vehicle is adjusted in real time to achieve vehicle balance.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for balancing a narrow-body vehicle based on a control moment gyroscope, characterized in that, Includes the following steps: S1 establishes the dynamic equations for the control moment gyroscope and the active roll dynamics model for narrow-body vehicles; Based on the vehicle roll dynamics model obtained in S1, S2 calculates the roll angle error and roll rate error of the vehicle. S3 uses a sliding mode control method to design an active tilt controller, which controls the tilt angle error and tilt angular velocity error calculated in S2 to obtain the rotational angular velocity of the control moment gyroscope frame; S4 utilizes the active roll controller designed in S3 to adjust the control moment gyroscope on the narrow-body vehicle in real time to achieve vehicle balance; The vehicle model is simplified with the following assumptions: First, the vehicle body and control moment gyroscope are multiple rigid entities; second, the tires only experience rolling friction with the ground; third, the vehicle actively tilts to the right; an active tilting dynamics model is established: In the formula, m The total mass of the vehicle; I x For vehicles to bypass x Moment of inertia of the shaft; φ This refers to the vehicle's roll angle; F y This refers to the lateral force of the tire; h The height of the center of mass; Define the control inputs for the vehicle roll system model The state variables are Assuming angle If the value is small, then the system equation is: ； When the vehicle is in a state of steering balance, both roll acceleration and lateral acceleration are zero. At this time, the gyro precession torque is zero, and the lateral force of the vehicle can be expressed as: The desired vehicle roll angle is In the formula, v For vehicle speed, The desired yaw rate of the vehicle is obtained based on an ideal linear two-degree-of-freedom model: In the formula, μ The road surface adhesion coefficient, L This refers to the vehicle's wheelbase. δ f The steering angle of the front wheels; To reduce system chattering, a saturation function is used instead of the sign function in the sliding surface reaching law, resulting in the control law: By applying sliding mode control to the vehicle roll angle error and roll rate error, the control quantity is obtained, namely the precession angular velocity of the control moment gyroscope frame. .

2. The method for narrow-body vehicle balance control based on a control moment gyroscope according to claim 1, characterized in that, The narrow-body vehicle structure includes a frame, tires mounted on the frame, and a control torque gyroscope mounted on the frame. The control torque gyroscope includes a gyroscope frame and a rotor mounted on the gyroscope frame. The gyroscope frame is driven by a frame motor, and the rotor is driven by a rotor motor. The two frame motors adjust the two torque gyroscope frames to generate angles of the same magnitude but opposite directions. Two rotor motors control two rotors to move at angular velocities of the same magnitude but in opposite directions. It rotates on its own axis.

3. The narrow-body vehicle balance control method based on a control moment gyroscope according to claim 2, characterized in that, The roll angle error is calculated based on the desired roll angle and the actual measured roll angle. In the formula, φ This indicates the actual roll angle of the vehicle as measured. Similarly, the roll rate error can be expressed as: In the formula, This indicates the vehicle's desired roll rate. This indicates the vehicle's actual roll rate.

4. The narrow-body vehicle balance control method based on a control moment gyroscope according to claim 3, characterized in that, The designed sliding surface s is In the formula, c is a constant and satisfies the Hurwitz condition, i.e., c > 0; To ensure the system quickly approaches the sliding surface, the exponential reaching law is adopted as the sliding surface reaching law: In the formula, This indicates the approach velocity to the sliding surface. k This represents the control gain, and all values ​​are constant.

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