CN103291483B - Load is uprushed the electric-control motor of anti-stall method, device and this device of use - Google Patents

Abstract

The present invention provides a method and device for preventing flameout caused by a sudden load increase and an electronically controlled engine using the device. The method includes: judging whether the condition for a sudden load increase is met, and if so, entering into a condition arbitration process; through the condition arbitration process, judging whether Satisfy the idle speed increase condition, if the condition is met, it will enter the idle speed increase process; the so-called idle speed increase process is to increase the preset deviation value on the original idle speed set value, and the calculated set value will be output according to the selected method; when the torque reaches the preset When the range is set and the speed reaches the set value, it enters the idle speed boost exit process and restores the original idle speed set value. After identifying the sudden increase in load, the solution of the present invention immediately increases the low idle speed setting value, which shortens the response time of the engine to calculate the sudden increase in torque, thereby overcoming the occurrence of flameout caused by the sudden increase in engine load, and when the load decreases After the engine is turned off, the engine can return to the original low idle speed setting to reduce fuel consumption.

Description

Anti-stall method and device for load sudden increase and electronically controlled engine using the device

technical field

The invention relates to the field of engine control, in particular to a method and device for preventing sudden increase of low idle load and an electronically controlled engine using the device.

Background technique

During the operation of the electronically controlled engine, the idling state accounts for a large proportion, and it is very important to control the stable operation of the engine under the idling state. For electronically controlled engines, the stable operation of the engine depends on ECU (Electronic Control Unit, engine electronic control unit) for control. If the load of the electronically controlled engine is running at a low idle speed, the load suddenly increases, and the idle speed cannot be raised in time, which will cause the speed of the electronically controlled engine to drop, or even stall.

The control strategy of the existing electronically controlled engine at idle speed is closed-loop control, that is, the torque of the engine is calculated based on the deviation between the actual engine speed and the set speed. The control relies on the speed deviation to calculate the engine output torque. Only when the speed deviation is large enough, the torque calculated by the ECU can overcome the load, but at this time the engine speed is too low, the engine cannot fully output the torque calculated by the ECU, and eventually the engine speed continues to drop. eventually lead to flameout.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for preventing flameout due to sudden load increase in order to solve the problem that the electronically controlled engine is easy to flame out when the load suddenly increases when the electronically controlled engine is running at a low idle speed.

Concrete technical scheme of the present invention is:

A load sudden increase anti-stall method, which is used to control an electronically controlled engine under low idle speed conditions of a loader or a dump truck, comprising the following process:

Condition judging process: When the electronically controlled engine is running at low idle speed, judge whether the load sudden increase condition is met, and if so, enter the condition arbitration process; the load sudden increase condition is that the torque increase and the speed decrease exceed the preset value;

Condition arbitration process: judge whether the shutdown condition is satisfied, if not, enter the idle speed increase process; the shutdown condition is: the water temperature is too high or the throttle fails or the preset time is not exceeded after the startup is successful;

Idle speed increase process: Add the preset deviation value to the original idle speed set value to obtain the increased idle speed set value, and the increased idle speed set value is output according to the selected method.

Further, the output mode of increasing the original idle speed setting value to the boosted idle speed setting value is: no slope limitation, output limitation with a certain slope or variable slope limitation.

Further, after the idle speed increase process, an idle speed increase exit process is also included: when the engine load decreases, the torque reaches the preset range and the rotational speed reaches the set value, the original idle speed set value is restored for operation.

Further, the output mode of the idle speed setting includes: when the original idle speed setting value is increased to the raised idle speed setting value, no slope limit is performed; when the raised idle speed setting value is reduced to the original idle speed setting value, the slope is limited The slope limit output; the original idle speed setting value and the increased idle speed setting value both limit the output with a certain slope when increasing and decreasing; the original idle speed setting value and the increased idle speed setting value increase and decrease with a certain slope Variable slope limits output.

A load sudden increase anti-stall device, which is used for an electronically controlled engine in a low idle condition of a loader or a dump truck, comprising the following modules:

The condition judging module is used to judge whether the load sudden increase condition is satisfied, and when the load sudden increase condition is met, the condition arbitration module is started; the load sudden increase condition is that the torque increase and the rotational speed decrease exceed the preset value;

The condition arbitration module is used to judge whether the shutdown condition is satisfied, and when the shutdown condition is not satisfied, the idle speed setting value calculation module is started; the shutdown condition is: the water temperature is too high or the throttle fails or the preset time is not exceeded after the startup is successful;

The idle speed setting value calculation module is used to increase the preset deviation value on the original idle speed setting value to obtain the increased idle speed setting value;

The idle speed output module is used to output the set value of idle speed.

Further, the way of the idle speed output module outputting the idle speed setting value includes: when the original idle speed setting value is increased to the raised idle speed setting value, the slope limit is not performed, and the raised idle speed setting value is reduced to the original idle speed setting value. When the value is fixed, the output is limited with a certain slope; the original idle speed setting value and the increased idle speed setting value are both limited with a certain slope when increasing and decreasing; the original idle speed setting value and the increased idle speed setting value are in the Output limited with variable slope when increasing and decreasing.

An electronically controlled engine includes the above-mentioned load sudden increase anti-flame device.

Compared with the prior art, the above technical solution has the following beneficial effects:

The solution of the preferred embodiment of the present invention immediately increases the low idle speed setting value after identifying a sudden increase in load, shortening the response time for the electronically controlled engine to calculate a sudden increase in torque, thereby overcoming the problem of flameout caused by the sudden increase in the load of the electronically controlled engine occur.

In a further preferred embodiment of the present invention, when the load decreases, the electronically controlled engine can be controlled to return to the original low idle speed setting value for operation, so as to reduce fuel consumption.

Description of drawings

Fig. 1 is the flow chart of embodiment 1 of the anti-flame-out method for sudden increase of low idle speed load of electronically controlled engine of the present invention;

Fig. 2 is a flow chart of Embodiment 2 of the method for preventing a sudden increase in the load of an electronically controlled engine at low idle speed according to the present invention.

detailed description

In order to make the above objects, features and advantages of the present invention more comprehensible, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Example 1 of the Flameout Prevention Method for Load Sudden Increase

The load sudden increase anti-stall method shown in Figure 1 is used for electronically controlled engines under low idle speed conditions: when the electronically controlled engine is running at low idle speed, first determine whether the load sudden increase condition is met, that is, determine whether the torque increases , Whether the rotational speed drops and exceeds the preset value, if it is, check whether the electronically controlled engine has no shutdown conditions, and at the same time, enter the idle speed increase process (that is, increase the preset deviation value on the original idle speed set value, increase The final idle speed setting value can be output according to the selected method). When the load decreases, the torque reaches the preset range and the speed reaches the set value, it enters the exit process and restores the original low idle speed set value.

During specific implementation, when judging whether the load sudden increase condition is satisfied, if there is no load sudden increase, that is, the torque does not increase, the speed does not decrease, or the degree of torque increase and the degree of speed decrease do not exceed the preset value, it will operate in the original low idle state ; When the electronically controlled engine is running, if there is a shutdown condition (such as high water temperature or throttle failure, etc.), it will run according to the original low idle state.

In the present invention, so-called "idling speed" refers to the state of the engine when the accelerator pedal is fully released when the engine is running. Idle speed is to overcome the running resistance of the engine itself and maintain the minimum engine speed.

Embodiment 2 of the flameout prevention method for sudden load increase

As shown in Figure 2, the load sudden increase anti-flame method is used for electric motors under low idle speed conditions, and its implementation steps are as follows:

Step 1 Condition judgment process: After the startup is successful and the preset time exceeds, judge whether the electronically controlled engine is running at low idle speed and whether the load has increased, causing the speed to drop beyond the preset value and the torque to rise beyond the preset value. If so, then Proceed to step 2.

If the electronically controlled engine running at low idle speed is successfully started, if the load suddenly increases (for a loader, a load sudden increase refers to loading a large amount of goods; for a dump truck, it refers to the rotation of the dump truck loaded with goods), which will cause the engine to The rotational speed decreases and the torque increases. If the rotational speed decreases and the slope exceeds the preset value, and the torque (collected by the torque filter) rises also exceeds the preset value, the conditional arbitration process is started.

Step 2: condition arbitration process: when there is no shutdown condition (also called exit condition, such as high water temperature, throttle failure, or valid accelerator but depressing the accelerator pedal), the engine starts the idle speed increase process.

In the present invention, the so-called "shutdown condition" means that the engine is in an abnormal operation state during operation, and the engine is operated at a low idle speed for self-protection reasons. The so-called shutdown conditions include: the water temperature is too high and the throttle fails. For example, when the engine detects that the operating temperature is too high (generally 80°C to 90°C), even if the engine satisfies the condition of a sudden increase in load under low idle conditions in step 1, resulting in a decrease in speed and an increase in torque, the condition arbitration will not be initiated. Process, at this time, run according to the original idle speed setting value of the engine.

Optionally, it also includes a process of judging whether the entry condition is satisfied, and the above entry condition includes: the vehicle using the engine is in the braking state, the air conditioner is on, the low-speed operation state, the engine is in the clutch state, and the engine has been successfully started for more than a certain period of time.

Step 3. Idle speed increase process: according to the correction algorithm, the low idle speed setting value is increased by an appropriate positive deviation value.

Due to the change of the dynamic characteristics of the system caused by the change of the load, by measuring the variables concerned and comparing them with the expected values, according to the correction algorithm, various parameters such as the engine speed, torque and fuel injection quantity are measured, compared and executed, so as to correct the adjustment control system response.

In the present invention, PID control and PI control are used to implement the correction algorithm. The so-called PID control refers to proportional-integral-derivative control; the so-called PI control refers to proportional-integral control, P is proportional control, the output is proportional to the input error signal, I is integral control, and the integrator accumulates the error Used to eliminate steady-state errors.

Through the correction algorithm, the positive deviation of the engine idle speed should be increased after the load sudden increase can be calculated.

Step 4 Idle speed boost exit process: When the shutdown condition occurs (such as the water temperature is too high, the accelerator is invalid or the accelerator is valid but the accelerator pedal is depressed) or the engine reaches the set speed and the torque reaches the preset range, the original idle speed setting value will be restored to output.

Before the process of increasing the idle speed, the closing condition is the same as that in step 2. At this time, the process of increasing the idle speed is not carried out, and the engine is operated according to the original idle speed setting value; if the closing condition occurs after the process of increasing the idle speed, enter The idle speed increase exit process, the engine returns to the original idle speed setting value for output.

When the engine reaches the set speed and the torque reaches the preset range, the engine will return to the original low idle condition to save fuel.

Step 5 Idle speed output process: In order to make the idle speed set value increase or decrease after a period of time without causing damage to the engine, the idle speed set value is output according to one of the following three output methods: a. When the idle speed setting value is increased to the raised idle speed setting value, no slope limitation is performed, and when the raised idle speed setting value is reduced to the original idle speed setting value, the output is limited by a certain slope (Figure 4.1); the original idle speed setting Both the fixed value and the boosted idle speed set value limit the output with a certain slope when increasing and decreasing (Figure 4.2); the original idle speed setting value and the boosted idle speed setting value use a variable slope when increasing and decreasing Limit the output (4.3 in the figure).

Optionally, the above idle speed increase exit process may not be carried out, that is, after the original idle speed setting value passes through the idle speed increase process, the improved idle speed setting value is calculated, and after the original idle speed setting value is increased to the boosted In the process of the idle speed setting value, the output mode of the idle speed is: a. no slope limit; b. certain slope limit output; c. variable slope limit output.

Optionally, if the torque and rotational speed do not reach the set value during the process of increasing the idle speed, continue the process of increasing the idle speed until reaching the set value.

The anti-stall method can make the engine without load operate at low idle speed; when the load suddenly increases, the engine idle speed can be increased in time, so that the engine will not cause the speed to drop due to the sudden load increase until the engine is turned off; When the engine reaches the set speed and torque, the engine will return to the original low idle condition, so as to achieve energy saving effect.

Embodiment of load sudden increase flameout prevention device

A load sudden increase anti-flame device, used for electronically controlled engines under low idle speed conditions, including the following modules: a condition judgment module, which is used to judge whether the load sudden increase condition is met, and can start the condition arbitration module; the condition arbitration module, It is used to judge whether the idle speed increase condition is met, and can start the idle speed set value calculation module; the idle speed set value calculation module is used to calculate the idle speed value that needs to be increased; the idle speed output module is used to output the idle speed set value.

The working process of this device is as follows: firstly, the condition judging module is used to judge whether the load sudden increase condition is satisfied, if it is satisfied, the condition arbitration module is started, and the condition arbitration module is used to judge whether the idle speed increase condition is met, and if so, check whether the engine is Closing condition, when there is no closing condition, start the idle speed setting value calculation module, calculate the idle speed setting value that needs to be increased through the idle speed setting value calculation module, that is, add the preset deviation value to the original idle speed setting value, so The boosted idle speed setting value is output through the idle speed output module. When the load decreases, the torque reaches the preset range and the speed reaches the set value, it enters the exit process and resumes the original low idle speed set value for operation.

Wherein, the idle speed setting value calculation module can use a correction algorithm to calculate the positive deviation that needs to be increased, and the increased idle speed setting value can be output in a selected manner. In the present invention, PID control and PI control are used to implement the correction algorithm.

During specific implementation, the idle speed set value output by the idle speed output module includes the original idle speed set value and the raised idle speed set value: when the load sudden increase or the idle speed increase condition is not satisfied, the original idle speed set value is output ; When the load sudden increase and idle speed increase conditions are satisfied, the idle speed set value after the increase is output. The way of the idle speed output module outputting the idle speed setting value includes: when the original idle speed setting value is increased to the raised idle speed setting value, the slope limit is not performed, and when the raised idle speed setting value is reduced to the original idle speed setting value Limit the output with a certain slope; the original idle speed setting value and the increased idle speed setting value both limit the output with a certain slope when increasing and decreasing; the original idle speed setting value and the increased idle speed setting value increase and decrease Hours limit the output with a variable slope.

It should be noted that the device can be used in conjunction with an electronic control unit (Electronic Control Unit, ECU for short), or be a part of the ECU unit.

Embodiment of electronically controlled engine

An electronically controlled engine includes the anti-flame-off device for sudden load increase. When the electronically controlled engine is running at low idle speed, judge whether the load sudden increase condition is met, that is, judge whether the torque increases, whether the speed decreases and exceeds the preset value, and if so, check whether the engine has no shut-down condition, and if there is no shut-down condition At the same time, it enters the process of increasing the idle speed (that is, adding a preset deviation value on the original idle speed setting value, the idle speed setting value calculation module uses a correction algorithm to calculate the positive deviation that needs to be increased, and the idle speed setting value after the promotion can be selected according to the selected value. output in a specified way). When the load decreases, the torque reaches the preset range and the speed reaches the set value, it enters the exit process and restores the original low idle speed set value.

Taking the Weichai Power 7L engine as an example, further explain the working process of the present invention: first judge whether the engine is started, only when the engine is started successfully and exceeds 2s, the engine is at a low idle speed, and the speed drops by more than 20 rpm due to the increase in load. If the torque rises more than 50 Nm and there is no shutdown condition, the engine will raise the engine idle speed setting value by a positive deviation value according to the correction algorithm. The original idle speed setting value of this model is 700 rpm, and the value after the increase However, according to different models, the original idle speed setting value and the increased value can be set according to the working conditions, and the idle speed setting value is output according to one of the three selected output modes.

Optionally, when the shutdown condition occurs, output according to the original idle speed setting value;

Optionally, when the idle speed increase condition is satisfied, it is possible to enter the idle speed increase state after the engine is started for any time between 1 and 10 seconds;

Optionally, the interval of the set value of the rotational speed drop can be set to any value between 10 and 50 r/min, and the interval of the set value of the torque rise can be set to any value between 30-100 Nm.

It should be noted that engines of other models may also work with reference to the set values in this embodiment. For example, when the engine starts for more than any time between 1 and 10 seconds, it is possible to enter the state of idle speed increase; The fixed value range can be set to any value between 30-100 Nm.

When the load sudden increase anti-flame device of the present invention is applied to other models, the idle speed increase condition, the original idle speed setting value, the idle speed setting value after the increase, the speed setting value and the torque setting value, etc. can be adjusted according to different models. Make specific settings.

The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation and application + scope In summary, the contents of this specification should not be construed as limiting the present invention.

Claims (7)

1. load is uprushed an anti-stall method, for the electric-control motor under the low idling operation of loader or dump truck is controlled, it is characterised in that include procedure below:

Conditional judgment process: when engine low-idle state is run, it may be judged whether meet load and uprush condition, if yes then enter condition arbitrated procedure；The described load condition of uprushing is that moment of torsion increases and rotating speed decrease beyond preset value；

Condition arbitrated procedure: judge whether to meet closedown condition, if it is not, then enter idling lifting process；Described closedown condition is: water temperature over-high or throttle lost efficacy or started after successfully not less than Preset Time；

Idling lifting process: increasing default deviation value, the idling setting value after getting a promotion in former idling setting value, the idling setting value after lifting exports according to selected mode.

2. load as claimed in claim 1 is uprushed anti-stall method, it is characterised in that former idling setting value increase to lifting after the way of output of idling setting value be: do not carry out slope restriction, with certain slope restriction output or variable slope restriction output.

3. load as claimed in claim 1 is uprushed anti-stall method, it is characterized in that, after described idling lifting process, also include idling lifting exit process: when engine loading reduces, when moment of torsion reaches preset range and rotating speed arrival setting value, recover former idling setting value and operate.

4. load as claimed in claim 3 is uprushed anti-stall method, it is characterised in that the way of output of idling setting value includes:

Former idling setting value increase to lifting after idling setting value time do not carry out slope restriction, with certain slope restriction output when the idling setting value after lifting is reduced to former idling setting value；

Idling setting value after former idling setting value and lifting all limits output with certain slope when increasing and reduce；

Idling setting value after former idling setting value and lifting limits output when increasing and reduce with variable slope.

5. load is uprushed an anti-flame device, for the electric-control motor under the low idling operation of loader or dump truck, it is characterised in that include with lower module:

Conditional judgment module, is used for judging whether meeting load and uprushes condition, when meet load uprush condition time, entry condition arbitration modules；The described load condition of uprushing is that moment of torsion increases and rotating speed decrease beyond preset value；

Condition arbitration modules, is used for judging whether to meet closedown condition, when being unsatisfactory for closedown condition, starts idling preset value calculation module；Described closedown condition is: water temperature over-high or throttle lost efficacy or started after successfully not less than Preset Time；

Idling preset value calculation module, for increasing default deviation value, the idling setting value after getting a promotion in former idling setting value；

Idling output module, is used for exporting idling setting value.

6. load as claimed in claim 5 is uprushed anti-flame device, it is characterised in that the mode of described idling output module output idling setting value includes:

Former idling setting value increase to lifting after idling setting value time do not carry out slope restriction, with certain slope restriction output when the idling setting value after lifting is reduced to former idling setting value；

Idling setting value after former idling setting value and lifting all limits output with certain slope when increasing and reduce；

Idling setting value after former idling setting value and lifting limits output when increasing and reduce with variable slope.

7. an electric-control motor, it is characterised in that include the load described in claim 5 or 6 and uprush anti-flame device.