A method and system for limiting an electric proportional brake valve

Abstract

The application discloses a limiting method and system for an electric proportional brake valve, and relates to the field of electric proportional brake valve control. The limiting method comprises the following steps: acquiring the hydraulic pressure of hydraulic oil, acquiring the reception condition of a zero point position signal generated when a lead screw is located at a zero point position at the current moment, and the reception condition of a maximum point position signal generated when the lead screw is located at a maximum point position, collecting the input current and feedback current of a motor in each cycle in real time, and then obtaining the motor current of the current cycle. Further, according to the motor current, the accumulated current and effective current are obtained. The hydraulic pressure, the reception condition of the zero point position signal, the reception condition of the maximum point position signal, the input current, the accumulated current and the effective current are comprehensively considered to determine the position and motion state of the lead screw, and then the motor is controlled to keep or stop running, and the stroke range of the lead screw is limited, so that the lead screw jamming, motor damage and other faults are avoided.

Description

Technical Field

[0001] This invention relates to the field of electro-proportional brake valve control, and in particular to an electro-proportional brake valve limiting method and system. Background Technology

[0002] The electro-proportional brake valve consists of a controller and a brake valve. The controller controls the start, stop, direction, and speed of the DC motor in the brake valve, and receives the actual operating current from the motor. Through a reducer, it drives a lead screw, converting the motor's rotation into the linear motion of the lead screw. The lead screw pushes a piston, compressing hydraulic oil and generating hydraulic pressure. The hydraulic pressure is fed back to the controller through a pressure sensor. When the lead screw exceeds its range of motion, it can cause the lead screw to jam, the motor to stall, and the brake to lock up. Summary of the Invention

[0003] The purpose of this invention is to provide a method and system for limiting the position of an electro-proportional brake valve. By judging the position and movement state of the lead screw, the range of motion of the lead screw can be limited by controlling the motor to avoid malfunctions.

[0004] To achieve the above objectives, the present invention provides the following solution:

[0005] A method for limiting the position of an electro-proportional brake valve, the method comprising:

[0006] Obtain the hydraulic pressure of the hydraulic oil in the brake valve;

[0007] According to a set time interval, the input current input from the controller to the motor in the brake valve in each cycle, and the feedback current of the motor corresponding to the input current are collected.

[0008] The motor current for the current cycle is obtained based on the input current and feedback current for each cycle.

[0009] Based on the current of each motor, the cumulative current and effective current are obtained;

[0010] The system acquires the reception status of the zero-point position signal generated when the lead screw is at the zero-point position at the current moment, and the reception status of the maximum point position signal generated when the lead screw is at the maximum point position; the reception status is either received or not received.

[0011] Based on the hydraulic pressure, the received zero-point position signal, the received maximum point position signal, the input current, the cumulative current, and the effective current, the motor is controlled to maintain or stop operation.

[0012] Optionally, based on the hydraulic pressure, the received zero-point position signal, the received maximum point position signal, the input current, the cumulative current, and the effective current, the motor is controlled to maintain or stop operation, specifically including:

[0013] Compare the hydraulic pressure with the pressure threshold.

[0014] When the hydraulic pressure is less than the pressure threshold, the lead screw is determined to have reached the zero position based on the reception of the zero position signal, the effective current, and the cumulative current.

[0015] If yes, when the input current is negative, control the motor to stop running; when the input current is positive, control the motor to keep running. If no, control the motor to keep running. When the input current is negative, the lead screw moves towards the zero position; when the input current is positive, the lead screw moves towards the maximum position.

[0016] When the hydraulic pressure is greater than or equal to the pressure threshold, it is determined whether the lead screw has reached the maximum position based on the reception of the maximum point position signal, the hydraulic pressure, and the cumulative current.

[0017] If yes, when the input current is positive, control the motor to stop running; when the input current is negative, control the motor to keep running; otherwise, control the motor to keep running.

[0018] Optionally, determining whether the lead screw has reached the zero position based on the received zero-point position signal, effective current, and cumulative current specifically includes:

[0019] Determine whether the zero-point position signal has been received at the current moment;

[0020] If so, the lead screw reaches the zero position;

[0021] If not, determine whether I is satisfied. 有效 ≥I 堵转 >0; where I 有效 For the effective current, I 堵转 The stall current of the motor;

[0022] If so, the lead screw reaches the zero position;

[0023] If not, determine whether I is satisfied. 累计 ≤I 门限1 <0; where I 累计 For the cumulative current, I 门限1 The preset threshold current is one;

[0024] If so, the lead screw reaches the zero position;

[0025] If not, the lead screw has not reached the zero point position.

[0026] Optionally, determining whether the lead screw has reached the maximum position based on the received maximum position signal, hydraulic pressure, and accumulated current specifically includes:

[0027] Determine whether the maximum point position signal has been received at the current moment;

[0028] If so, the lead screw reaches the maximum point position;

[0029] If not, determine whether the hydraulic pressure is greater than a preset value;

[0030] If so, the lead screw reaches the maximum point position;

[0031] If not, determine whether I is satisfied. 累计 ≥I 门限2 >0; where I 累计 For the cumulative current, I 门限2 The preset threshold current is two;

[0032] If so, the lead screw reaches the maximum point position;

[0033] If not, the lead screw has not reached the maximum point position.

[0034] Optionally, the motor current for the current cycle is obtained based on the input current and feedback current of each cycle, specifically including:

[0035] Using Formula I i =αI i输入 +(1-α)I i反馈 To obtain the motor current; where I i输入 For the input current, I i反馈 For the feedback current, I i Let I be the motor current, i be the number of cycles, i∈{1,2,...,n,...,N}, and α be the proportionality coefficient, α∈(0,1); when the input current is positive, the motor current I... i When the input current is negative, the motor current I is positive. i It is a negative value.

[0036] Optionally, the cumulative current is obtained based on the motor current, specifically including:

[0037] Using Formula I 累计 =I1+I2+...+I i-1 +I i The cumulative current is obtained; where I 累计 For the cumulative current, I i Let i be the motor current, and i be the number of cycles, i∈{1,2,...,n,...,N}.

[0038] Optionally, the effective current is obtained based on the motor current, specifically including:

[0039] Using formula Obtain the effective current I 有效 Among them, I i I is the motor current. 有效 Let M be the effective current, M be the length of the sliding window of the lead screw, and i be the number of cycles, i∈{1,2,...,n,...,N}, N≥i-M+1>0.

[0040] Optionally, the period is 4.5 to 5.5 ms.

[0041] To achieve the above objectives, the present invention also provides the following solution:

[0042] An electric proportional brake valve limiting system, the limiting system comprising:

[0043] The pressure acquisition unit is used to acquire the hydraulic pressure of the hydraulic oil in the brake valve;

[0044] The current acquisition unit is used to acquire the input current input by the controller to the motor in the brake valve and the feedback current of the motor corresponding to the input current at set time intervals.

[0045] The current calculation unit, connected to the current acquisition unit, is used to calculate the motor current of the current cycle based on the input current and feedback current of each cycle, and to calculate the cumulative current and effective current based on the current of each motor.

[0046] The position signal receiving unit acquires the reception status of the zero-point position signal generated when the lead screw is at the zero-point position at the current moment, and the reception status of the maximum-point position signal generated when the lead screw is at the maximum-point position; the reception status is either received or not received.

[0047] The central control unit, connected to the pressure acquisition unit, position signal receiving unit, and current calculation unit, is used to control the motor to keep or stop running based on the hydraulic pressure, the reception of the zero-point position signal, the reception of the maximum point position signal, the input current, the cumulative current, and the effective current.

[0048] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0049] This invention relates to an electro-proportional brake valve limiting method and system. The method includes: acquiring the hydraulic pressure of the hydraulic oil, acquiring the reception status of the zero-point position signal generated when the lead screw is at the zero-point position, and acquiring the reception status of the maximum point position signal generated when the lead screw is at the maximum point position; real-time acquisition of the input current and feedback current of the motor in each cycle to obtain the motor current of the current cycle; further, based on the current of each motor, obtaining the cumulative current and effective current; and comprehensively considering the hydraulic pressure, the reception status of the zero-point position signal, the reception status of the maximum point position signal, the input current, the cumulative current, and the effective current to determine the position and motion state of the lead screw, thereby controlling the motor to maintain or stop operation, limiting the stroke range of the lead screw, and avoiding faults such as lead screw jamming and motor damage. Attached Figure Description

[0050] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0051] Figure 1 This is a flowchart of the electro-proportional brake valve limiting method of the present invention;

[0052] Figure 2 This is a schematic diagram illustrating the operating principle of an electro-proportional brake valve.

[0053] Figure 3 A flowchart for determining whether the lead screw has reached the zero position;

[0054] Figure 4 A flowchart for determining whether the lead screw has reached its maximum position. Detailed Implementation

[0055] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0056] The purpose of this invention is to provide a method and system for limiting the movement of an electro-proportional brake valve, which determines the position and movement state of the lead screw and then controls the motor to limit the range of motion of the lead screw, thereby preventing malfunctions.

[0057] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0058] like Figure 1 As shown, the present invention provides a method for limiting the position of an electric proportional brake valve, specifically including:

[0059] Step S01: Obtain the hydraulic pressure of the hydraulic oil in the brake valve.

[0060] Step S02: According to the set time interval, collect the input current of the controller to the motor in the brake valve in each cycle, and the feedback current of the motor corresponding to the input current.

[0061] Step S03: Obtain the motor current for the current cycle based on the input current and feedback current for each cycle.

[0062] Step S04: Obtain the cumulative current and effective current based on the current of each motor.

[0063] Step S05: Obtain the reception status of the zero-point position signal generated when the lead screw is at the zero-point position, and the reception status of the maximum-point position signal generated when the lead screw is at the maximum-point position. The reception status is either received or not received.

[0064] Step S06: Based on the hydraulic pressure, the reception of the zero-point position signal, the reception of the maximum point position signal, the input current, the cumulative current, and the effective current, control the motor to maintain or stop operation.

[0065] Figure 2 This is a schematic diagram of the operating principle of an electro-proportional brake valve; the screw moves backward when the hydraulic pressure decreases, and forward when the hydraulic pressure increases; the maximum backward position of the screw is defined as the zero point, and the maximum forward position of the screw is defined as the maximum point; the screw moves between the zero point and the maximum point, and when the screw is at the zero point or the maximum point, the position sensor sends a signal to the controller.

[0066] When the lead screw is at zero, it does not contact the piston. The lead screw travels through a period of free stroke before contacting the piston and generating hydraulic pressure. If the lead screw retracts beyond the minimum point, it will cause the lead screw to jam, the motor to stall, and in severe cases, it will damage the motor. When the lead screw reaches the maximum point, it outputs the maximum hydraulic pressure. If the lead screw travels beyond the maximum point, it will cause the brake to lock up, and in severe cases, the hydraulic valve body will break.

[0067] Considering that the Hall position sensors commonly used are non-contact and have limited signal sensitivity, the controller may sometimes fail to receive the signal. In this case, the lead screw may run out of the zero or maximum point, causing damage to the electro-proportional brake valve. The electro-proportional brake valve limiting method provided by this invention determines the position and movement state of the lead screw by comprehensively considering the hydraulic pressure, input current, cumulative current, effective current, the reception of the zero position signal, and the reception of the maximum position signal, thereby controlling the motor operation and limiting the lead screw within a reasonable stroke range.

[0068] Specifically, based on the input current and feedback current of each cycle, the motor current of the current cycle is obtained, including:

[0069] Using Formula I i =αI i输入 +(1-α)I i反馈 To obtain the motor current; where I i输入 For the input current, I i反馈 For feedback current, I i Let I be the motor current, i be the number of cycles, i∈{1,2,...,n,...,N}, and α be the proportionality coefficient, α∈(0,1); when the input current is positive, the motor current I0 is... i When the input current is negative, the motor current I is positive. i It is a negative value.

[0070] Preferably, the period is 4.5 to 5.5 ms.

[0071] Furthermore, based on the motor current, the cumulative current and effective current are obtained, specifically including:

[0072] Using Formula I 累计 =I1+I2+...+I i-1 +I i The cumulative current is obtained; where I 累计 This is the cumulative current. Using the formula... The effective current is obtained; where I 有效 The effective current is M, which is the length of the sliding window of the lead screw, and N≥i-M+1>0.

[0073] Furthermore, based on the hydraulic pressure, the received zero-point position signal, the received maximum point position signal, the input current, the cumulative current, and the effective current, the motor is controlled to maintain or stop operation, specifically including:

[0074] Compare the hydraulic pressure with the pressure threshold.

[0075] When the hydraulic pressure is less than the pressure threshold, the lead screw is determined to have reached the zero position based on the reception of the zero position signal, the effective current, and the cumulative current.

[0076] If the input current is negative, the motor is stopped; if the input current is positive, the motor continues to run. If not, the motor continues to run. When the input current is negative, the lead screw moves towards the zero position; when the input current is positive, the lead screw moves towards the maximum position.

[0077] When the hydraulic pressure is greater than or equal to the pressure threshold, it is determined whether the lead screw has reached the maximum position based on the reception of the maximum point position signal, the hydraulic pressure, and the cumulative current.

[0078] If yes, when the input current is positive, control the motor to stop running; when the input current is negative, control the motor to keep running; otherwise, control the motor to keep running.

[0079] Preferably, the pressure threshold is 3% of the maximum hydraulic pressure.

[0080] Furthermore, such as Figure 3 As shown, determining whether the lead screw has reached the zero position based on the received zero-point position signal, effective current, and cumulative current specifically includes:

[0081] Determine whether the zero-point position signal has been received at the current moment.

[0082] If so, the lead screw reaches the zero point position.

[0083] If not, determine whether I is satisfied. 有效 ≥I 堵转 >0; where I 有效 For the effective current, I 堵转 The stall current of the motor is denoted as .

[0084] If so, the lead screw reaches the zero point position.

[0085] If not, determine whether I is satisfied. 累计 ≤I 门限1 <0; where I 累计 For the cumulative current, I 门限1 The preset threshold current is 1.

[0086] If so, the lead screw reaches the zero point position.

[0087] If not, the lead screw has not reached the zero point position.

[0088] Furthermore, such as Figure 4 As shown, determining whether the lead screw has reached the maximum position based on the received maximum position signal, hydraulic pressure, and accumulated current specifically includes:

[0089] Determine whether the maximum point position signal has been received at the current moment.

[0090] If so, the lead screw reaches the maximum point position.

[0091] If not, determine whether the hydraulic pressure is greater than a preset value.

[0092] If so, the lead screw reaches the maximum point position.

[0093] If not, determine whether I is satisfied. 累计 ≥I 门限2 >0; where I 累计 For the cumulative current, I 门限2 The preset threshold current is two.

[0094] If so, the lead screw reaches the maximum point position.

[0095] If not, the lead screw has not reached the maximum point position.

[0096] In addition, the present invention also provides an electric proportional brake valve limit system, the limit system comprising: a pressure acquisition unit, a position signal receiving unit, a current acquisition unit, a current calculation unit, and a central control unit.

[0097] The pressure acquisition unit is used to acquire the hydraulic pressure of the hydraulic oil in the brake valve.

[0098] The current acquisition unit is used to acquire the input current input by the controller to the motor in the brake valve and the feedback current of the motor corresponding to the input current at set time intervals.

[0099] The current calculation unit is connected to the current acquisition unit; the current calculation unit is used to calculate the motor current of the current cycle based on the input current and feedback current of each cycle, and to calculate the cumulative current and effective current based on the current of each motor.

[0100] The position signal receiving unit is used to acquire the reception status of the zero-point position signal generated when the lead screw is at the zero-point position at the current moment, and the reception status of the maximum-point position signal generated when the lead screw is at the maximum-point position. The reception status is either received or not received.

[0101] The central control unit is connected to the pressure acquisition unit, the position signal receiving unit, and the current calculation unit. The central control unit is used to control the motor to maintain or stop operation based on the hydraulic pressure, the received zero-point position signal, the received maximum point position signal, the input current, the cumulative current, and the effective current.

[0102] The electro-proportional brake valve limiting method and system provided by this invention controls the operation of the motor by judging the position and movement state of the lead screw. When the lead screw reaches the zero position, if the motor still drives the lead screw to retract, the motor stops; when the lead screw reaches the maximum position, if the motor still drives the lead screw to move forward, the motor stops. This limits the stroke range of the lead screw and avoids the situation of lead screw jamming and motor damage.

[0103] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the method section.

[0104] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for limiting the position of an electro-proportional brake valve, characterized in that, The method includes: Obtain the hydraulic pressure of the hydraulic oil in the brake valve; According to a set time interval, the input current input from the controller to the motor in the brake valve in each cycle, and the feedback current of the motor corresponding to the input current are collected. The motor current for the current cycle is obtained based on the input current and feedback current for each cycle. Based on the current of each motor, the cumulative current and effective current are obtained; The system acquires the reception status of the zero-point position signal generated when the lead screw is at the zero-point position at the current moment, and the reception status of the maximum point position signal generated when the lead screw is at the maximum point position; the reception status is either received or not received. Based on the hydraulic pressure, the received zero-point position signal, the received maximum point position signal, the input current, the cumulative current, and the effective current, the motor is controlled to maintain or stop operation, specifically including: Compare the hydraulic pressure with the pressure threshold. When the hydraulic pressure is less than the pressure threshold, the system determines whether the lead screw has reached the zero position based on the received zero-point position signal, the effective current, and the cumulative current. Specifically, this includes: determining whether the zero-point position signal has been received at the current moment; if yes, the lead screw has reached the zero position; if no, determining whether the following conditions are met. ≥ >0; where, The effective current, The stall current of the motor; if yes, the lead screw reaches the zero position; if no, determine whether the following conditions are met. ≤ <0; where, The cumulative current, If the preset threshold current is 1, then the lead screw reaches the zero position; otherwise, the lead screw does not reach the zero position. If yes, when the input current is negative, control the motor to stop running; when the input current is positive, control the motor to keep running. If no, control the motor to keep running. When the input current is negative, the lead screw moves towards the zero position; when the input current is positive, the lead screw moves towards the maximum position. When the hydraulic pressure is greater than or equal to the pressure threshold, it is determined whether the lead screw has reached the maximum position based on the reception of the maximum point position signal, the hydraulic pressure, and the cumulative current. If yes, when the input current is positive, control the motor to stop running; when the input current is negative, control the motor to keep running; otherwise, control the motor to keep running.

2. The method for limiting the electric proportional brake valve according to claim 1, characterized in that, Determining whether the lead screw has reached the maximum position based on the received maximum position signal, hydraulic pressure, and accumulated current includes: Determine whether the maximum point position signal has been received at the current moment; If so, the lead screw reaches the maximum point position; If not, determine whether the hydraulic pressure is greater than a preset value; If so, the lead screw reaches the maximum point position; If not, determine whether the condition is met. ≥ >0; where, The cumulative current, The preset threshold current is two; If so, the lead screw reaches the maximum point position; If not, the lead screw has not reached the maximum point position.

3. The method for limiting the electric proportional brake valve according to claim 1, characterized in that, The motor current for the current cycle is obtained based on the input current and feedback current of each cycle, specifically including: Using formula To obtain the motor current; where, The input current, The feedback current, Let i be the motor current, and i be the number of cycles, i∈{1,2,...,n,...,N}. This is the proportionality coefficient. When the input current is positive, the motor current... When the input current is negative, the motor current is positive. It is a negative value.

4. The method for limiting the electric proportional brake valve according to claim 1, characterized in that, Based on the motor current, the cumulative current is obtained, specifically including: Using formula The cumulative current is obtained; where The cumulative current, Let i be the motor current, and i be the number of cycles, i∈{1,2,...,n,...,N}.

5. The method for limiting the electric proportional brake valve according to claim 1, characterized in that, Based on the motor current, the effective current is obtained, specifically including: Using formula Obtain effective current ;in, The motor current, Let M be the effective current, M be the length of the sliding window of the lead screw, and i be the number of cycles, i∈{1,2,...,n,...,N}. .

6. The method for limiting the electric proportional brake valve according to claim 1, characterized in that, The period is 4.5~5.5ms.

7. An electro-proportional brake valve limit system, characterized in that, The limiting system includes: The pressure acquisition unit is used to acquire the hydraulic pressure of the hydraulic oil in the brake valve; The current acquisition unit is used to acquire the input current input by the controller to the motor in the brake valve and the feedback current of the motor corresponding to the input current at set time intervals. The current calculation unit, connected to the current acquisition unit, is used to calculate the motor current of the current cycle based on the input current and feedback current of each cycle, and to calculate the cumulative current and effective current based on the current of each motor. The position signal receiving unit is used to acquire the reception status of the zero-point position signal generated when the lead screw is at the zero-point position at the current moment, and the reception status of the maximum-point position signal generated when the lead screw is at the maximum-point position; the reception status is either received or not received. The central control unit, connected to the pressure acquisition unit, position signal receiving unit, and current calculation unit, is used to control the motor to maintain or stop operation based on the hydraulic pressure, the received zero-point position signal, the received maximum point position signal, the input current, the cumulative current, and the effective current. Specifically, it includes: Compare the hydraulic pressure with the pressure threshold. When the hydraulic pressure is less than the pressure threshold, the system determines whether the lead screw has reached the zero position based on the received zero-point position signal, the effective current, and the cumulative current. Specifically, this includes: determining whether the zero-point position signal has been received at the current moment; if yes, the lead screw has reached the zero position; if no, determining whether the following conditions are met. ≥ >0; where, The effective current, The stall current of the motor; if yes, the lead screw reaches the zero position; if no, determine whether the following conditions are met. ≤ <0; where, The cumulative current, If the preset threshold current is 1, then the lead screw reaches the zero position; otherwise, the lead screw does not reach the zero position. If yes, when the input current is negative, control the motor to stop running; when the input current is positive, control the motor to keep running. If no, control the motor to keep running. When the input current is negative, the lead screw moves towards the zero position; when the input current is positive, the lead screw moves towards the maximum position. When the hydraulic pressure is greater than or equal to the pressure threshold, it is determined whether the lead screw has reached the maximum position based on the reception of the maximum point position signal, the hydraulic pressure, and the cumulative current. If yes, when the input current is positive, control the motor to stop running; when the input current is negative, control the motor to keep running; otherwise, control the motor to keep running.

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