Method for calibrating step loss of stepping motor of on-line electro-jet throttle valve

Abstract

The invention discloses a step loss calibration method for a stepping motor of a general engine electric injection throttle valve. The step loss calibration method comprises the following steps that the throttle valve opening degree and the difference value between the target rotating speed and the actual rotating speed of the general engine are collected in real time; judging whether the stepping motor loses step or not and judging the step losing direction according to the opening degree of the throttle valve and the rotating speed difference value; and when the stepping motor loses steps and the rotating speed does not reach the target rotating speed, controlling the stepping motor to rotate in a low-speed mode for compensation. Whether the step of the stepping motor is lost and the step losing direction are judged by judging the opening degree of the throttle valve and the difference value between the target rotating speed and the actual rotating speed of the general gasoline engine. If the stepping motor loses steps and the rotating speed does not reach the target rotating speed, the stepping motor enters a stepping motor step loss compensation mode, the stepping motor is controlled to rotate at a low speed, and therefore larger torque can be provided to drive the throttle valve to rotate.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronic control of engine, in particular to a method for calibrating step loss of a throttle step motor of an engine. BACKGROUND

[0002] In the electronic injection system of an engine, a step motor is often used to adjust the throttle opening degree, thereby controlling the intake air quantity and affecting the engine speed and working condition. However, due to factors such as load change, electromagnetic interference, and motor characteristics, the step motor may lose steps during operation. Step loss may cause the throttle opening degree control to be inaccurate, resulting in a mismatch between the engine intake air quantity and the demand, and causing speed fluctuations, power drops, and even operation failures.

[0003] In the prior art, there are deficiencies in the compensation schemes for step loss of the step motor. Some schemes do not distinguish between the opening and closing directions of the step loss, and the compensation strategy has poor universality. Others have single step loss judgment conditions, and only rely on the motor step number or speed difference, which makes it difficult to accurately identify the step loss under complex working conditions, resulting in delayed compensation or false triggering. Therefore, a control method is needed that can accurately judge and compensate for step loss in the opening and closing directions of the step motor. SUMMARY

[0004] Therefore, the purpose of the present application is to develop a method for calibrating step loss of a throttle step motor of an engine. By judging the throttle opening degree and the difference between the target speed and the actual speed of the engine, it can be determined whether the step motor has lost steps and the direction of the step loss. If the step motor loses steps and the speed does not reach the target speed, the step motor enters a step loss compensation mode, and the step motor is controlled to rotate at a low speed, which can provide more torque to drive the throttle to rotate.

[0005] The method for calibrating step loss of a throttle step motor of an engine of the present application comprises the following steps:

[0006] Real-time acquisition of the throttle opening degree and the difference between the target speed and the actual speed of the engine;

[0007] According to the throttle opening degree and the speed difference, it is determined whether the step motor has lost steps and the direction of the step loss;

[0008] When the step motor loses steps and the speed does not reach the target speed, the step motor is controlled to rotate at a low speed for compensation.

[0009] The method for calibrating step loss of a throttle step motor of an engine of the present application comprises a closing direction step loss compensation control process, which comprises the following steps:

[0010] Start the closing direction step loss judgment and perform the initialization operation;

[0011] judging whether the demand intake air quantity integral value reaches the minimum value, if not, exiting the step motor direction step loss compensation mode; if yes, continuing to judge;

[0012] judging whether the current throttle opening degree is greater than the minimum throttle opening degree, if not, exiting the step motor direction step loss compensation mode; if yes, continuing to judge;

[0013] judging whether the current step motor step number is 0, if not, exiting the step motor direction step loss compensation mode; if yes, continuing to judge;

[0014] judging whether the target speed and the current speed difference is less than 0, if not, exiting the step motor direction step loss compensation mode; if yes, entering the step motor direction step loss compensation mode, and controlling the step motor to rotate in the closing direction at a low speed.

[0015] The step loss calibration mode of the throttle step motor of the engine electronic injection throttle valve of the present application comprises an opening direction step loss compensation control flow, which comprises the following steps:

[0016] starting the opening direction step loss judgment, and performing an initialization operation;

[0017] judging whether the demand intake air quantity integral value reaches the maximum value, if not, exiting the step motor opening direction step loss compensation mode; if yes, continuing to judge;

[0018] judging whether the current throttle opening degree is less than the minimum throttle opening degree, if not, exiting the step motor opening direction step loss compensation mode; if yes, continuing to judge;

[0019] judging whether the current step motor step number is the maximum value, if not, exiting the step motor opening direction step loss compensation mode; if yes, continuing to judge;

[0020] judging whether the target speed and the current speed difference is greater than 0, if not, exiting the step motor opening direction step loss compensation mode; if yes, entering the step motor opening direction step loss compensation mode, and controlling the step motor to rotate in the opening direction at a low speed.

[0021] Further, the initialization operation is used to reset the related parameters and state identifiers in the step loss compensation control flow, and to provide initial conditions for the step loss judgment and compensation execution.

[0022] Further, the demand intake air quantity integral value is obtained by integral operation on the related parameters of the engine intake demand, and is used to reflect the cumulative state of the engine intake demand.

[0023] Further, the current throttle opening degree is obtained by a throttle position sensor, and the minimum throttle opening degree is a minimum opening degree threshold value of the throttle allowed by the engine control system and pre-set by the engine control system.

[0024] Further, the current stepping motor step number is obtained by a motor step number counting module, and the maximum value of the stepping motor step number is the maximum step number threshold that the stepping motor can run in the full open direction, which is determined by the motor characteristics and system design.

[0025] Further, the target speed difference from the current speed is calculated after the target speed and the current speed are collected by the engine speed sensor, to reflect the deviation between the engine speed control requirement and the actual speed.

[0026] The present application has the following advantages: The present application accurately calculates the dynamic difference between the target speed and the actual speed of the engine by collecting the throttle opening signal in real time. Based on parameter judgment: On the one hand, the matching degree of the actual throttle opening change and the theoretical control step number of the stepping motor is compared to identify whether there is a step loss anomaly; on the other hand, the influence trend of the step loss on the speed control is determined according to the direction and threshold of the speed difference, so as to accurately identify whether the stepping motor loses steps and the direction of the step loss. When it is determined that the stepping motor loses steps and the speed does not reach the target, the step loss compensation mode is triggered, and the stepping motor is driven at a speed lower than the conventional control by taking advantage of the characteristic that the output torque of the stepping motor is larger when running at low speed. This low-speed strategy can not only avoid the problem of step loss aggravation caused by insufficient torque of the motor running at high speed, but also effectively overcome the interference of the mechanical resistance of the throttle, air flow load and other disturbances by relying on the increased torque, to stabilize the throttle to return to the theoretical control position, quickly correct the air intake deviation, and accurately converge the engine speed to the target value, thereby fundamentally solving the pain point that the traditional control cannot accurately regulate the speed due to step loss. BRIEF DESCRIPTION OF DRAWINGS

[0027] The present application will be further described below in conjunction with the drawings and embodiments:

[0028] Figure 1 The flow chart for the step loss compensation control in the closing direction.

[0029] Figure 2 The flow chart for the step loss compensation control in the opening direction. DETAILED DESCRIPTION

[0030] The step loss calibration method for the electric injection throttle stepping motor of the engine of the present embodiment comprises the following steps:

[0031] The throttle opening and the difference between the target speed and the actual speed of the engine are collected in real time.

[0032] The stepping motor is determined to lose steps and the direction of the step loss according to the throttle opening and the speed difference.

[0033] When the stepping motor loses steps and the speed does not reach the target speed, the stepping motor is controlled in low-speed mode for compensation.

[0034] For example, Figure 1, the step motor of the throttle of the engine loses step calibration mode, including the closing direction step loss compensation control process, the control process includes the following steps:

[0035] Start the closing direction step loss judgment, and perform the initialization operation;

[0036] Judge whether the demand intake quantity integral value reaches the minimum value, if not, exit the step motor closing direction step loss compensation mode; if yes, continue to judge; From the engine running logic, the demand intake quantity integral value is a cumulative quantitative embodiment of the engine intake demand. When the integral value reaches the minimum value, it means that the engine intake demand is in a low and stable cumulative state under the current working condition. At this time, if the step motor loses step in the closing direction, the influence on the engine intake control will be more significant, and compensation needs to be started to accurately control the throttle opening.

[0037] If the demand intake quantity integral value does not reach the minimum value, it means that the cumulative degree of engine intake demand has not reached the corresponding working condition. Even if the step motor loses step in the closing direction, its interference with the intake control under the current working condition is relatively small, or starting compensation may excessively interfere with normal intake adjustment, which may otherwise cause engine running fluctuations. Therefore, by judging whether the demand intake quantity integral value reaches the minimum value as a precondition for closing direction step loss compensation, the working condition that really needs compensation can be accurately selected, the compensation mode is prevented from being mistakenly triggered, the engine is ensured to be in a reasonable working condition, and only when the cumulative state of the intake demand is suitable, the subsequent more detailed step loss compensation judgment process is entered, the accuracy and reliability of the entire step loss compensation control are improved, the step motor closing direction step loss compensation is timely and accurate, and the actual intake control demand of the engine is met.

[0038] Judge whether the current throttle opening is greater than the minimum throttle opening, if not, exit the step motor closing direction step loss compensation mode; if yes, continue to judge;

[0039] If the current step motor step number is not 0, the step motor direction step loss compensation mode is exited; if the current step motor step number is 0, the step motor direction step loss compensation mode is continued to be judged; from the functional characteristics of the throttle, the minimum opening degree of the throttle is the critical value pre-marked by the engine control system, representing the opening degree lower limit for maintaining the basic idle speed or the minimum stable air intake requirement. When the current opening degree of the throttle is less than or equal to the minimum opening degree, it means that the throttle has reached or is close to the physical state of "closed to the limit", and theoretically the adjustment space of the step motor in the closing direction is extremely narrow. At this time, if it is determined that the "closing direction step loss" and the compensation is forcibly started, on the one hand, the physical feasibility of the step motor driving the throttle to continue to rotate in the closing direction is extremely low; on the other hand, excessive attempts to compensate in the closing direction will break the balance of the minimum air intake requirement of the engine, causing idle speed instability, misfire and other serious faults. When the current opening degree of the throttle is greater than the minimum opening degree, it means that the throttle still has physical space for further adjustment in the closing direction, and the current air intake has not reached the "minimum stable requirement" bottom line. At this time, if the step motor has a closing direction step loss, the compensation operation can correct the opening degree deviation caused by the step loss without damaging the basic operating conditions of the engine, so that the air intake amount returns to the reasonable control range.

[0040] If the difference between the target speed and the current speed is not less than 0, the step motor direction step loss compensation mode is exited; if the difference between the target speed and the current speed is less than 0, the step motor direction step loss compensation mode is entered, and the step motor is controlled to rotate in the closing direction at a low speed. This step, the difference between the target speed and the current speed reflects the deviation direction of the actual speed of the engine relative to the control requirement: when the difference is less than 0, it means that the current speed is higher than the target speed, and the engine needs to reduce the air intake amount to reduce the speed. If the step motor loses steps in the closing direction under this working condition, it will cause the actual closing amount of the throttle to be insufficient, the air intake amount will not be reduced as expected, and the speed will continue to be higher than the target value.

[0041] The step motor step loss calibration method of the engine electric injection throttle valve of the application comprises an opening direction step loss compensation control process, which comprises the following steps:

[0042] The opening direction step loss judgment is started, and the initialization operation is performed;

[0043] determining whether the demand intake air quantity integral value reaches a maximum value, if not, exiting the step motor opening direction step loss compensation mode; if yes, continuing to determine; firstly, starting the opening direction step loss determination to perform an initialization operation, resetting the step motor step count, emptying the demand intake air quantity integral buffer, resetting the state identifier and the like, ensuring that the determination process starts with uniform initial conditions, avoiding historical data interference. Then, determining whether the demand intake air quantity integral value reaches a maximum value - the integral value is obtained by integrating the accelerator pedal depth, engine load signal and the like, reflecting the maximum demand of the engine on the intake air quantity (such as high load working condition). If the integral value does not reach the maximum value, it indicates that the current intake air demand does not trigger the potential risk of opening direction step loss, and forced compensation may cause excessive intake air, so the mode is exited; if the maximum value is reached, it indicates that the engine urgently needs to increase the intake air quantity, and further determination is needed.

[0044] determining whether the current throttle opening degree is less than the minimum throttle opening degree, if not, exiting the step motor opening direction step loss compensation mode; if yes, continuing to determine; if the opening degree is not less than the value, it indicates that the throttle still has opening space, and the step loss risk is low, so the compensation is exited; if the opening degree is less than the value, it indicates that the actual opening amount of the throttle is insufficient, which may be caused by opening direction step loss.

[0045] determining whether the current step motor step number is the maximum value, if not, exiting the step motor opening direction step loss compensation mode; if yes, continuing to determine; if the step number does not reach the maximum value, it indicates that the motor does not reach the full opening limit, and the step loss possibility is low, so the compensation is exited; if the step number is the maximum value, in combination with the previous integral value reaching the standard and the insufficient opening degree, it can be determined that the motor may occur step loss in the opening direction.

[0046] determining whether the difference between the target speed and the current speed is greater than 0, if not, exiting the step motor opening direction step loss compensation mode; if yes, entering the step motor opening direction step loss compensation mode to control the step motor to rotate in the opening direction at a low speed. By determining whether the difference between the target speed and the current speed is greater than 0, if the difference is not greater than 0, it indicates that the speed demand is irrelevant to the opening direction adjustment, so the compensation is exited; if the difference is greater than 0, it indicates that the engine needs to increase the intake air quantity by opening the throttle to increase the speed, but the adjustment is invalid due to step loss, so the compensation mode is entered to control the motor to rotate in the opening direction at a low speed lower than the normal speed. The low speed strategy utilizes the characteristic of the step motor that the torque is large at low speed to overcome the mechanical resistance with greater driving force, forcibly corrects the throttle opening degree, ensures that the intake air quantity matches the high load demand, and makes the speed quickly approach the target value.

[0047] In the embodiment, the initialization operation is used to reset the related parameters and state identifier in the step loss compensation control process, to provide initial conditions for step loss determination and compensation execution.

[0048] In the embodiment, the demand intake quantity integral value is obtained by integral operation on the related parameters of the engine intake demand, and is used to reflect the cumulative state of the engine intake demand.

[0049] In the embodiment, the current throttle opening degree is obtained by a throttle position sensor, and the minimum throttle opening degree is a minimum opening degree threshold value of the throttle allowed and pre-set by the engine control system.

[0050] In the embodiment, the current step motor step number is obtained by a motor step number counting module, and the maximum step motor step number is a maximum step number threshold value of the step motor in the full opening direction, which is determined by the motor characteristics and system design.

[0051] In the embodiment, the target speed and current speed difference is obtained by calculating the target speed and current speed collected by the engine speed sensor, and is used to reflect the deviation between the engine speed control demand and the actual speed.

[0052] The above only is the preferred embodiment of the present application, and is not used to limit the present application, for the person skilled in the art, the present application can have various changes and changes; any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application, are included in the protection scope of the present application.

Claims

1. A method for calibrating step loss of a stepper motor in a general-purpose electronic fuel injection throttle body, characterized in that, The method comprises the following steps: Real-time acquisition of throttle opening degree and difference between target speed and actual speed of the engine; Judgment of step loss and step loss direction of the stepper motor according to the throttle opening degree and the speed difference; When the stepper motor loses steps and the speed does not reach the target speed, the stepper motor is controlled to rotate in a low-speed mode for compensation.

2. The step loss calibration method for the stepper motor of the general-purpose electronic fuel injection throttle valve according to claim 1, characterized in that: The control process comprises the following steps: Start of the step loss judgment in the closing direction and execution of an initialization operation; Judgment of whether the integral value of the required intake air quantity reaches a minimum value, and if not, the step loss compensation mode of the stepper motor in the closing direction is exited; if yes, the judgment is continued; Judgment of whether the current throttle opening degree is greater than the minimum throttle opening degree, and if not, the step loss compensation mode of the stepper motor in the closing direction is exited; if yes, the judgment is continued; Judgment of whether the current step number of the stepper motor is 0, and if not, the step loss compensation mode of the stepper motor in the closing direction is exited; if yes, the judgment is continued; Judgment of whether the difference between the target speed and the current speed is less than 0, and if not, the step loss compensation mode of the stepper motor in the closing direction is exited; if yes, the step loss compensation mode of the stepper motor in the closing direction is entered, and the stepper motor is controlled to rotate in the low-speed closing direction.

3. The method of claim 1, wherein the method further comprises: determining a number of steps that the motor has lost; and determining a number of steps that the motor has gained. The control process comprises the following steps: Start of the step loss judgment in the opening direction and execution of an initialization operation; Judgment of whether the integral value of the required intake air quantity reaches a maximum value, and if not, the step loss compensation mode of the stepper motor in the opening direction is exited; if yes, the judgment is continued; Judgment of whether the current throttle opening degree is less than the minimum throttle opening degree, and if not, the step loss compensation mode of the stepper motor in the opening direction is exited; if yes, the judgment is continued; Judgment of whether the current step number of the stepper motor is the maximum value, and if not, the step loss compensation mode of the stepper motor in the opening direction is exited; if yes, the judgment is continued; Judgment of whether the difference between the target speed and the current speed is greater than 0, and if not, the step loss compensation mode of the stepper motor in the opening direction is exited; if yes, the step loss compensation mode of the stepper motor in the opening direction is entered, and the stepper motor is controlled to rotate in the low-speed opening direction.

4. The step loss calibration method for the stepper motor of the general-purpose electronic fuel injection throttle valve according to claim 2 or 3, characterized in that: The initialization operation is used for resetting related parameters and state identifiers in the step loss compensation control process, and providing initial conditions for the step loss judgment and compensation execution.

5. The method of claim 2 or 3, wherein the method further comprises: determining a number of steps of the stepper motor that have been taken since the last calibration; and determining the number of steps of the stepper motor that have been taken since the last calibration by counting a number of times the pulse signal has been received since the last calibration. The integral value of the required intake air quantity is obtained by integral operation on related parameters of the intake air requirement of the engine, and is used for reflecting the cumulative state of the intake air requirement of the engine.

6. The method of claim 2 or 3, wherein the method further comprises: determining a number of steps of the stepper motor that have been taken since the last calibration; and determining the number of steps of the stepper motor that have been taken since the last calibration by counting a number of times the pulse signal has been received since the last calibration. The current throttle opening degree is obtained by a throttle position sensor, and the minimum throttle opening degree is a minimum opening degree threshold value of the throttle allowed and pre-set by the engine control system.

7. The method of claim 2 or 3, wherein the method further comprises: determining a number of steps of the stepper motor that have been taken since the last calibration; and determining the number of steps of the stepper motor that have been taken since the last calibration by counting a number of times the pulse signal has been received since the last calibration. The current step number of the stepper motor is obtained by a motor step number counting module, and the maximum step number of the stepper motor is a maximum step number threshold value of the stepper motor in the full opening direction, which is determined by motor characteristics and system design.

8. The method of claim 2 or 3, wherein the method further comprises: determining a number of steps of the stepper motor that have been taken since the last calibration; and determining the number of steps of the stepper motor that have been taken since the last calibration by counting a number of times the pulse signal has been received since the last calibration. The difference between the target speed and the current speed is calculated after the target speed and the current speed are respectively acquired by an engine speed sensor, and is used for reflecting the deviation between the speed control requirement and the actual speed of the engine.

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