Finite-time anti-interference compound control method for windscreen wiper system
By adopting a limited-time anti-interference composite control method in the wiper system, the problem of slow response speed in the face of multiple interferences is solved, and more efficient anti-interference control is achieved, which improves the stability and speed of the system.
Patent Information
- Application Number
- CN202411768700.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-04
- Publication Date
- 2025-04-15
AI Technical Summary
When existing wiper systems face interference such as electromagnetic interference, foreign object friction, external environment changes and sensor errors, they are prone to over-adjustment or under-adjustment, resulting in slow response speed and inability to respond to sudden interference in time, affecting stability and robust performance.
The finite-time anti-interference composite control method is adopted, including establishing a wiper motor dynamic model, designing a high-gain finite-time disturbance observer, designing a controller dynamic adaptive law and a finite-time state feedback controller. Through these steps, a finite-time composite controller is formed to achieve efficient anti-interference control of the wiper system.
It improves the anti-interference performance of the wiper system, avoids motion shock caused by excessive adjustment, improves the dynamic performance and control accuracy of the system, enhances the stability and speed of the system, and improves user experience and driving safety.
Smart Images
Figure CN119821328A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of wiper systems, and in particular to a finite-time anti-interference composite control method for wiper systems. Background Art
[0002] The wiper system is a mechanical device that wipes the windshield of a car, used to clean dust, rain, snow, etc. on the windshield to ensure the driver's clear vision. It is one of the important mechanisms for safe driving of a car. Its reliability directly affects the safety of the driver. Especially with the continuous increase in the speed of modern cars, the safety performance requirements of the wiper system are getting higher and higher, and the structural design and control methods need to be further improved.
[0003] Currently, wiper systems are subject to interference during operation, including electromagnetic interference, frictional interference from foreign objects on the glass surface, external environmental factors (such as wind and rain intensity fluctuations, ice and snow cover), sensor errors, and system parameter perturbations. Due to the uncertainty of these interferences, traditional feedback control systems are prone to overshoot (system overreaction) or undershoot (system underreaction). Traditional feedback control typically relies on sensor detection and subsequent adjustments, resulting in slow system response and an inability to respond promptly to sudden disturbances. This, in turn, impacts the stability and robustness of the wiper system. Current wiper control systems are still based on traditional feedback control, which suffers from poor robustness under various operating conditions, affecting both stability and robustness. Mismatched disturbances are typically not directly reflected in the system's output or measurable state variables, making them difficult to directly capture through conventional observation methods. Because these disturbances are not directly related to the control input, traditional control strategies (such as feedback-based control methods) are often unable to effectively address them. Wiping angle deviations are typically caused by wear of the wiper mechanism or control deviations, which further reduces the overall lifespan of the wiper system, resulting in a reduced user experience, impacting driving safety, and even customer churn. Summary of the Invention
[0004] The present invention aims to solve the above technical problems and provides a finite-time anti-interference composite control method for a wiper system.
[0005] In order to solve the above technical problems, the technical solution provided by the present invention is:
[0006] A finite-time anti-interference composite control method for a wiper system comprises the following steps:
[0007] S1. Establish a dynamic model of the wiper motor:
[0008] The relationship between wiper arm motion and motor motion angle can be correlated by table lookup method, and the position control of wiper motor system can be focused on. The overall wiper motor model is established as follows:
[0009]
[0010] Define the motor position x1 = θ, the motor speed x3=i, and the wiper motor model state space equation is established as follows:
[0011]
[0012] According to the external disturbance d, which includes the non-matching disturbance d1 and the matching disturbance d2, formula 2 is simplified;
[0013] S2. Design a high-gain finite-time disturbance observer to estimate the disturbance:
[0014] According to the non-smooth control strategy and the external disturbance d, the following high-gain finite-time disturbance observer is designed to calculate the system matching disturbance and non-matching disturbance for feedforward compensation:
[0015]
[0016]
[0017] S3. Design the controller dynamic adaptive law:
[0018] By performing state coordinate transformation, the steady-state expected function of each state and the control input expected function can be constructed, and the reference position trajectory is y r ,but
[0019] Based on the adaptive regulation control strategy, a dynamic adaptive law is designed:
[0020]
[0021] S4. Design a finite-time state feedback controller:
[0022] S5. According to the above steps, a finite time compound controller is constructed to design the motor voltage output value:
[0023] Design the following finite time state feedback controller and output voltage,
[0024]
[0025] Preferably, Formula 2 in S1 is simplified as follows:
[0026]
[0027] Preferably, the non-matching disturbance and can be regarded as external load interference, and f1 is the unknown interference outside the system.
[0028] Preferably, w 1,1 =x1,w 2,1 =x2,w 3,1 =x3, is the observed value of each state; and is the derivative of d1 Observation value; is the observed value of d2; β i (i=1,2,3) is a design parameter.
[0029] Preferably, L i =[l i,1 ,l i,2 …l i,n-i+2 ] T (i=1,2,3) is the observer weight gain vector, and satisfies the Hurwitz polynomial R(s)=s n-i+2 +l i,1 s n-i+1 …+l i,n-i+1 s+l i,n-i+2 =0; is the observer homogeneity.
[0030] The simplified result of formula 2 is as follows;
[0031]
[0032] Preferably, in S3, the state weight gain l is introduced, and the state coordinate can be transformed into the following form: η1 = (x1-x1 * ) / l ρ ,η2(x2-x2 * ) / l ρ+1 ,η3(x3-x3 * ) / l ρ+2 ,v=(uu * ) / l ρ+3 , where u * is the expected control quantity.
[0033] Preferably, in S5, k1, k2, k3 are controller adjustment gains, κ is the controller homogeneity, and v is the control law after the state change loop.
[0034] Preferably, u is the output voltage of the wiper motor, i is the output current, R is the phase resistance, L is the phase inductance, E a is the back electromotive force, k e is the back electromotive force constant, w is the motor speed, T e is the electromagnetic torque, T L is the inertia torque of the scraper arm, T fis the friction torque, B is the motor damping coefficient, k t is the electromagnetic torque constant, and J is the motor moment of inertia.
[0035] After adopting the above method, the present invention has the following advantages:
[0036] Compared with existing traditional feedback control, the proposed anti-interference composite control strategy for the wiper system can be applied to electronic wipers to improve the anti-interference performance of the wiper system. The designed control algorithm demonstrates its superiority in the simplicity of the controller expression and parameter selection criteria. By adaptively adjusting the controller proportional gain at different disturbance levels, motion oscillations caused by over-adjustment can be avoided, thereby improving the dynamic performance of the system. The finite-time composite controller proposed based on non-smooth theory can improve the control accuracy, speed, and system stability of the moving wiper, increase driver safety while driving, and at the same time increase the overall service life of the wiper system, ensuring customer satisfaction and retention.
[0037] The above summary is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments and features described above, further aspects, embodiments and features of the present invention will be readily apparent by reference to the accompanying drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS
[0038] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0039] Figure 1 is a flow chart of the present invention;
[0040] Figure 2 This is a block diagram of the finite time anti-interference composite control of the present invention. DETAILED DESCRIPTION
[0041] Specific embodiments of the present invention will now be mentioned in detail. Although the present invention is described in conjunction with these specific embodiments, it should be appreciated that the present invention is not intended to be limited to these specific embodiments. On the contrary, these embodiments are intended to cover substitutions, changes or equivalent embodiments that may be included in the spirit and scope of the invention defined by the claims. In the following description, a large amount of specific details are set forth to provide a comprehensive understanding of the present invention. The present invention can be implemented without some or all of these specific details. In other cases, in order not to make the present invention unnecessarily obscure, well-known process operations are not described in detail.
[0042] When used in conjunction with "including," "methods comprising," or similar language in this specification and the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
[0043] The present invention will be described in further detail below in conjunction with the full text.
[0044] Combined with attachment Figure 1 and Figure 2 A finite-time anti-interference composite control method for a wiper system comprises the following steps:
[0045] S1. Establish a dynamic model of the wiper motor:
[0046] The relationship between wiper arm motion and motor motion angle can be correlated by table lookup method, and the position control of wiper motor system can be focused on. The overall wiper motor model is established as follows:
[0047]
[0048] Define the motor position x1 = θ, the motor speed x3=i, and the wiper motor model state space equation is established as follows:
[0049]
[0050] According to the external disturbance d, which includes the non-matching disturbance d1 and the matching disturbance d2, formula 2 is simplified;
[0051] S2. Design a high-gain finite-time disturbance observer to estimate the disturbance:
[0052] According to the non-smooth control strategy and the external disturbance d, the following high-gain finite-time disturbance observer is designed to calculate the system matching disturbance and non-matching disturbance for feedforward compensation:
[0053]
[0054]
[0055] S3. Design the controller dynamic adaptive law:
[0056] By performing state coordinate transformation, the steady-state expected function of each state and the control input expected function can be constructed, and the reference position trajectory is y r ,but
[0057] Based on the adaptive regulation control strategy, a dynamic adaptive law is designed:
[0058]
[0059] S4. Design a finite-time state feedback controller:
[0060] S5. According to the above steps, a finite time compound controller is constructed to design the motor voltage output value:
[0061] Design the following finite time state feedback controller and output voltage,
[0062]
[0063] Formula 2 in S1 is simplified as follows;
[0064]
[0065] The non-matching disturbance and can be regarded as external load interference, and f1 is the unknown interference outside the system.
[0066] w 1,1 =x1,w 2,1 =x2,w 3,1 =x3, is the observed value of each state; and is the derivative of d1 Observation value; is the observed value of d2; β i (i=1,2,3) is a design parameter.
[0067] L i =[l i,1 ,l i,2 …l i,n-i+2 ] T (i=1,2,3) is the observer weight gain vector, and satisfies the Hurwitz polynomial R(s)=s n-i+2 +l i,1 s n-i+1 …+l i,n-i+1 s+l i,n-i+2 =0; is the observer homogeneity.
[0068] The simplified result of formula 2 is as follows;
[0069]
[0070] In S3, the state weight gain l is introduced, and the state coordinate can be transformed into the following form: η1=(x1-x1 *) / l ρ ,η2(x2-x2 * ) / l ρ+1 ,η3(x3-x3 * ) / l ρ+2 ,v=(uu * ) / l ρ+3 , where u * is the expected control quantity.
[0071] In S5, k1, k2, k3 are controller adjustment gains, κ is the controller homogeneity, and v is the control law after the state change loop.
[0072] u is the output voltage of the wiper motor, i is the output current, R is the phase resistance, L is the phase inductance, E a is the back electromotive force, k e is the back electromotive force constant, w is the motor speed, T e is the electromagnetic torque, T L is the inertia torque of the scraper arm, T f is the friction torque, B is the motor damping coefficient, k t is the electromagnetic torque constant, and J is the motor moment of inertia.
[0073] When the present invention is specifically implemented, Figure 2 As shown, the method proposed in the present invention can be divided into two technical parts. One is based on a non-recursive synthesis framework, which designs a simple non-smooth composite control scheme, and the other is based on an adaptive control strategy, which adaptively scales the control gain strategy according to different disturbance levels.
[0074] Working principle of the present invention:
[0075] S1. First, we can use the table lookup method to correlate the wiper arm motion and motor motion angle, so we mainly focus on the wiper motor system position control. The overall wiper motor model is as follows:
[0076]
[0077] Where, u is the wiper motor output voltage (unit: V), i is the output current (unit: A), R is the phase resistance (unit: Ω), L is the phase inductance (unit: H), E a is the back electromotive force (unit: H), k e is the back electromotive force constant (unit is V / rpm), w is the motor speed (unit is rad / s), T e is the electromagnetic torque (unit: N·m), T L is the inertia torque of the scraper arm (unit: N·m), T f is the friction torque (unit is N·m), B is the motor damping coefficient (unit is N·m / rad / s), kt is the electromagnetic torque constant (unit is N·m / A), J is the motor moment of inertia (unit is m 2 ·kg).
[0078] Define the motor position x1 = θ, the motor speed x3=i. Based on the above dynamic model, the state space equation of the wiper motor model is established:
[0079]
[0080] Considering the system mismatch disturbance Match the disturbance d2. It can be regarded as external load interference, and f1 is the unknown interference outside the system.
[0081] Then the system formula 2 can be simplified into the following form:
[0082]
[0083] Based on the establishment of the above state space model, the controller is designed according to the following control strategy:
[0084] (1) According to the non-smooth control strategy, considering the unknown disturbance of the system, the following high-gain finite-time disturbance observer is designed to estimate the system matching disturbance and non-matching disturbance for feedforward compensation:
[0085]
[0086]
[0087] Among them, w 1,1 =x1,w 2,1 =x2,w 3,1 =x3. are the observed values for each state. is the derivative of d1 Observed value. is the observed value of d2. i (i=1,2,3) is a design parameter.
[0088] L i =[l i,1 ,l i,2 …l i,n-i+2 ] T (i=1,2,3) is the observer weight gain vector, and satisfies the Hurwitz polynomial R(s)=s n-i+2 +l i,1 s n-i+1 …+l i,n-i+1 s+l i,n-i+2 =0. is the observer homogeneity.
[0089] (2) To facilitate the subsequent controller design and processing, state coordinate transformation is required. The steady-state expected function of each state and the control input expected function can be constructed as follows:
[0090] Set the reference position trajectory to y r ,but
[0091] Introducing the state weight gain l, the state coordinate can be transformed into the following form: η1=(x1-x1 * ) / l p ,η2=(x2-x2 * ) / l ρ+1 ,η3(x3-x3 * ) / l ρ+2 ,v=(uu * ) / l ρ+3 .
[0092] (3) Based on the adaptive regulation control strategy, a dynamic adaptive law is designed:
[0093]
[0094] Among them, λ is the adaptive law adjustment gain, e s is the systematic observation error, and σ is the bound of the systematic observation error.
[0095] Based on the above steps and non-smooth theory, the following finite-time state feedback controller and output voltage are designed:
[0096]
[0097] Among them, k1, k2, k3 are controller adjustment gains, and κ is the controller homogeneity.
[0098] In summary, the present invention employs a high-gain finite-time disturbance observer to estimate system disturbances for feedforward compensation, and a finite-time state feedback controller. These two components combine to provide composite control of the wiper system, achieving global finite-time stability and improving system speed and anti-interference capabilities. An adaptive law is also designed to dynamically adjust the controller gain, avoiding system oscillations caused by excessive gain and improving the system's dynamic and static performance.
[0099] The present invention and its embodiments are described above. This description is not restrictive. What is shown in the full text is only one embodiment of the present invention, and the actual structure is not limited thereto. In short, if a person skilled in the art is inspired by this and, without departing from the purpose of the present invention, designs a structure and embodiment similar to this technical solution without creatively designing, they shall all fall within the scope of protection of the present invention.
Claims
1. A finite-time anti-interference composite control method for a wiper system, characterized in that: The following steps are involved: S1. Establish the dynamic model of the wiper motor: The table lookup method can be used to correlate the wiper arm motion and motor motion angle relationship, and pay attention to the position control of the wiper motor system. The overall wiper motor model is established as follows: Define the motor position x1 = θ, the motor speed x3=i, and the state space equation of the wiper motor model is established as follows: According to the external disturbance d, the external disturbance d includes the non-matching disturbance d1 and the matching disturbance d2, formula 2 is simplified; S2. Design a high-gain finite-time disturbance observer to estimate the disturbance: According to the non-smooth control strategy and external disturbance d, the following high-gain finite-time disturbance observer is designed to calculate the system matching disturbance and non-matching disturbance for feedforward compensation: S3. Design the controller dynamic adaptive law: After state coordinate transformation, the steady-state expected function of each state and the control input expected function can be constructed, and the reference position trajectory is y r , then x1 * =y r , Based on the adaptive control strategy, a dynamic adaptive law is designed: S4. Design a finite-time state feedback controller: S5. According to the above steps, a finite time compound controller is constructed to design the motor voltage output value: Design the following finite time state feedback controller and output voltage, 2. According to claim 1, a finite-time anti-interference composite control method for a wiper system is characterized by: Formula 2 in S1 is simplified as follows; 3. The finite-time anti-interference composite control method for a wiper system according to claim 2, characterized in that: The non-matching disturbance and can be regarded as external load interference, and f1 is the unknown interference outside the system.
4. The finite-time anti-interference composite control method for a wiper system according to claim 1, characterized in that: w 1,1 =x1,w 2,1 =x2,w 3,1 =x3, are the observed values of each state; and is the derivative of d1 Observation value; is the observed value of d2; β i (i=1,2,3) is a design parameter.
5. The finite-time anti-interference composite control method for a wiper system according to claim 1, characterized in that: L i =[l i,1 ,l i,2 …l i,n-i+2 ] T (i=1,2,3) is the observer weight gain vector, and satisfies the Hurwitz polynomial R(s)=s n-i+2 +l i,1 s n-i+1 …+l i,n-i+1 s+l i,n-i+2 =0; is the observer homogeneity.
6. The finite-time anti-interference composite control method for a wiper system according to claim 1, characterized in that: The simplified result of formula 2 is as follows; 7. The finite-time anti-interference composite control method for a wiper system according to claim 1, characterized in that: In S3, state weight gain is introduced Then the state coordinates can be transformed into the following form: Among them, u * is the expected control quantity.
8. The finite-time anti-interference composite control method for a wiper system according to claim 1, characterized in that: In S5, k1, k2, k3 are controller adjustment gains, κ is the controller homogeneity, and v is the control law after the state change loop.
9. The finite-time anti-interference composite control method for a wiper system according to claim 1, characterized in that: u is the wiper motor output voltage, i is the output current, R is the phase resistance, L is the phase inductance, E a is the back electromotive force, k e is the back electromotive force constant, w is the motor speed, T e is the electromagnetic torque, T L is the inertia torque of the scraper arm, T f is the friction torque, B is the motor damping coefficient, k t is the electromagnetic torque constant, and J is the motor moment of inertia.