KR20130088910A

KR20130088910A - Apparatus and method for diagonising output of engine of hybrid vehicle

Info

Publication number: KR20130088910A
Application number: KR1020120009293A
Authority: KR
Inventors: 김한신
Original assignee: 콘티넨탈 오토모티브 시스템 주식회사
Priority date: 2012-01-31
Filing date: 2012-01-31
Publication date: 2013-08-09

Abstract

The present invention discloses an apparatus and method for diagnosing engine power.

Description

Apparatus and method for diagnosing engine power in hybrid vehicles {APPARATUS AND METHOD FOR DIAGONISING OUTPUT OF ENGINE OF HYBRID VEHICLE}

The present invention relates to an apparatus and method for diagnosing engine power of a hybrid vehicle, and more particularly, to perform engine output diagnosis caused by frequent engine driving and stopping operations in a hybrid vehicle which temporarily suspends engine driving when the vehicle is temporarily stopped during driving. It relates to a device and a method to be able to.

The hybrid car is a next-generation car equipped with an internal combustion engine and a motor engine at the same time and dramatically reducing fuel consumption and harmful gas emissions compared to conventional vehicles, such as minimizing air resistance by dramatically reducing the weight of the vehicle body. In many cases, emissions of harmful gases can be reduced by more than 90% compared to existing vehicles, which can improve the air and the surrounding environment of large cities, and are also called eco-cars because they fit well with traffic control and road planning.

The hybrid vehicle uses a motor engine that has better torque characteristics than an engine that is an internal combustion engine in a low speed region, and an engine that has better torque characteristics than a motor engine in a relatively medium and high speed region, and pauses while driving. In this case, by stopping the engine driving, fuel efficiency can be improved by providing efficient power according to the driving state of the vehicle, and in the case of low-speed driving, the engine is not used, and the emission of harmful emissions can be minimized. have.

However, in such hybrid vehicles, if engine combustion becomes unstable, the engine will not start properly first. In a hybrid vehicle, the starter motor cranks to start the engine.If the engine is not properly burned even after cranking for the allowable time, the cranking stops and the engine is stopped, and then the cranking for starting the engine is repeated again. If the engine is not properly burned after the permitted time, the cranking stops and the engine is stopped.

At this time, if the engine combustion becomes unstable while driving the engine, the signal values of the relevant sensors appear abnormally under the engine partial load operating conditions.

If the engine output is poor, the vehicle will be driven with insufficient or no engine power, so the HCU will continue to start or drive the motor to drive the engine or drive the vehicle. Over time, this can cause a sudden drop in battery charge.

The present invention has been made in view of the above circumstances, and an object of the present invention is to consider the failure of starting by the initial cold start and not consider the initial start three times, and then continue the engine in the short engine start and the hybrid controller afterwards. If the engine keeps repeating short start and engine stop despite requesting operation, confirm that there is no problem with the starter motor, check the battery charge rate to see if the battery is sufficient, and then start and stop the engine more than 5 times. It is an object of the present invention to provide an engine output diagnosis apparatus and method for diagnosing an engine combustion failure of a hybrid vehicle which determines that there is a problem in engine combustion, sends an error determination signal of the engine controller to the hybrid controller, and executes the lymphhome mode. .

The present invention has been made in view of the above circumstances, and another object to be achieved in the present invention is that if the combustion instability occurs after the oxygen sensor located at the front end of the catalyst is activated, the amount of injected fuel is higher than the allowable value ( 10 ms / rotation) The oxygen sensor value shows a high value for lean burn. (2.5 ~ 3 volt) And the air-fuel ratio value is 1.5 ~ 4 or more. Combustion instability is determined using the results of the oxygen sensor at the front end of the catalyst. If the combustion instability occurs after the oxygen sensor located at the end of the purchase is activated, the value of the oxygen at the rear end of the catalyst remains very low despite the engine partial load. . (<0.1 volt) If the oxygen sensor condition is such that the HCU is requesting partial engine load under the allowable engine load condition, the engine output may be faulty if it remains constant for a certain period of time. You will be running in Lymphhome mode.

According to an aspect of the present invention for achieving the above object, there is provided a fuel injection control apparatus for a hybrid vehicle, such an apparatus,

As described above, the engine control apparatus and method of the hybrid vehicle according to the present invention,

The following drawings attached in this specification are illustrative of the preferred embodiments of the present invention, and together with the detailed description of the invention to serve to further understand the technical spirit of the present invention, the present invention is a matter described in such drawings It should not be construed as limited to.
1 is a diagram illustrating a configuration of an engine control apparatus of a hybrid vehicle according to an exemplary embodiment of the present invention.

In order to fully understand the present invention, operational advantages of the present invention, and objects achieved by the practice of the present invention, reference should be made to the accompanying drawings and the accompanying drawings which illustrate preferred embodiments of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the preferred embodiments of the present invention with reference to the accompanying drawings. Like reference symbols in the drawings denote like elements.

1) In the present invention, when the engine output does not come out properly due to some cause in the hybrid vehicle, the engine output is diagnosed and the result is notified to the driver so that the necessary actions can be taken. Failure to properly output the engine may include poor engine combustion due to fuel supply interruption, low fuel, poor ignition or inability to ignite. Therefore, the present invention is to introduce a method for diagnosing a poor engine output by grasping the phenomenon of engine combustion failure. 2) If engine combustion becomes unstable, the engine will not start properly first. In hybrid vehicles, the starter motor cranks to start the engine. If the engine is not properly burned after cranking for the allowable time, the cranking stops and the engine is stopped. After that, it will try again and again to crank the engine. If the engine is still not burning properly after the permitted time, the cranking will stop and the engine will stop. The present invention does not consider the initial start-up three times in consideration of the start-up failure due to the initial cold start in this situation, the engine continues to short start and stop even though the engine is requested to continue short engine start and HCU afterwards If it repeats, check that there is no problem with the starting motor, check the battery SOC to see if the battery is sufficient, and if the engine starts and stops more than 5 times, it is determined that there is a problem with engine combustion, and the ECU error determination signal is sent to the HCU. You will be running in Lymphhome mode.

3) If engine combustion becomes unstable while driving the engine, the signal values of the relevant sensor are abnormal under the engine partial load operating condition.

Shows a trend. The present invention calculates the diagnostic counter when the related signals show this unstable tendency to output the engine.

It will diagnose the defect. If combustion instability occurs after the oxygen sensor located in front of the catalyst is activated, injection

Despite the fuel level is above acceptable (10 ms / revolution), the oxygen sensor value shows a high value of lean combustion. (2.5 ~ 3 volt) And the air-fuel ratio value is 1.5 ~ 4 or more. Combustion instability can be identified using the results of the oxygen sensor in front of the catalyst. If combustion instability occurs after the oxygen sensor located at the rear end of the catalyst is activated, the rear end oxygen sensor value remains very low despite the engine partial load. (<0.1 volt) If the oxygen sensor condition is such that the HCU is requesting partial engine load under the permissible engine load condition and it is maintained for a certain period of time, it is determined that there is a problem with the engine output and an ECU error determination signal is sent to the HCU. 4) If the engine output is poor, the vehicle will run with low or no engine power, so the HCU will continue to start or to drive the engine or drive the motor. Will drive the vehicle. As a result, as time goes by, the battery filling rate is rapidly lowered, which may eventually lead to battery problems. After the ECU informs the HCU that it is unable to do so, limit the vehicle output torque to drive the engine from the current battery charge rate to the minimum allowable battery charge rate or to allow the driver to start the engine again. Some allow the lymphatic groove to run. 5) If the engine power is abnormal due to engine instability, the driver should be informed quickly and concisely that the engine cannot drive the vehicle. In addition, the present invention not only turns on the engine check lamp but also turns on the engine emergency warning light in order to prevent driving problems and safety accidents caused by insufficient engine power.

Or you can give a warning message to the driver through announcements such as sound or text, which will give you a warning in advance and allow the driver to evacuate the vehicle properly in the event of a problem.

Alternatively, the engine warning light and service lamp light up when the engine is diagnosed poorly, and when the battery charge level reaches the minimum allowable value (~ 35%), an additional emergency light is turned on to stop the vehicle limp drive. This ensures a minimum mileage for the driver to evacuate to a safe zone in an emergency.

1) Taking into account the initial failure caused by cold start, excluding the initial failure 3 times can be done in consideration of the coolant or ambient air temperature at engine start. If there is a high possibility of starting failure after side and cold start, the start failure exclusion count is increased, and in normal starting, the possibility of starting failure is low.

2) In addition to engine power, you can also monitor engine power indirectly through motor current. If the current engine power is within the allowable value compared to the target engine power required by the HCU, the diagnosis is started. Normally, the output of the engine and the output of the motor are summed up to the final output, but if the engine output problem occurs due to poor engine combustion, the final torque output comes out of the motor output alone.

Therefore, if the torque output ratio of the motor output to the final output in the normal case or the current value currently being used for driving the motor against the allowable motor current in the normal case exceeds the allowable value, the engine output is not appropriate and the motor is responsible for the output. After the allowable delay has elapsed, the ECU or motor controller notifies the HCU that the engine power is not adequate and switches the vehicle into limp home mode.

3) In addition to engine power, you can also monitor engine power indirectly through battery charge. When the engine starts charging by the command of the HCU, the battery is charged by the engine running. If the battery does not charge, there is a problem with the battery control module or a problem with the battery. Therefore, even if the battery itself is not abnormal and the battery control module has no abnormality, it can be determined that the engine is not outputting properly if the battery is not charged by the engine operation. Therefore, in such a case, it is determined that the engine power is not normal, the HCU is notified of the error, and the vehicle is switched to the limp home mode.

4) If the fuse for the ECU spark plug is broken, ignition will not be possible and the engine will not burn, resulting in a problem with the engine output. Even if the ignition is not performed, the same phenomenon as in the case of no injection occurs, and the engine combustion failure can be checked by using the signal value of the oxygen sensor at the front and rear of the catalyst, the engine load, and the injector injection time.

5) If the fuse for the ECU spark plug is broken, if the ECU can measure the current applied to the spark plug, you can check the ECU spark plug fuse for abnormalities. That is, when the secondary current operating time during the ECU controlled ground operation time for the ignition flowing through the ignition plug is read in a situation where it is determined that the ignition is performed under the engine driving condition, the ECU is lowered below the allowable value during engine operation. You can determine that the engine is experiencing poor engine combustion.

.6) If it is determined that there is a problem with the engine output as shown above, the engine operation is switched to the lymph groove mode. Lymphhome mode is as follows. If the battery charge level is above the allowable level (> 40%), the driver should be allowed to drive to a safe zone with a minimum of driving. To ensure maximum mileage with this limited battery level, the HCU limits the vehicle's maximum torque output with Lymphhome mode applied. (40% or less of normal driving)

It also stops running lymphatic grooves (~ 35%) near the minimum battery level for engine start for the next start after stopping. Or, for safety reasons, continue to drive the lymph groove while limiting the maximum torque of the vehicle until it stops.

7) Limiting the vehicle's output torque for the limp groove can be kept constant (less than 40%) compared to normal driving conditions, but the limiting output torque can be variably limited depending on the remaining battery level. For example, if the battery level is 60% when lymph groove drive is applied, the maximum power is limited to 50% compared to normal operation. If the battery level is 40%, the maximum power is limited to 30% or less compared to normal operation. It is. At 35% near the battery level limit, the maximum power is limited to less than 10% compared to normal operation.

The engine output diagnosis device and method of the hybrid vehicle can bring a great progress in terms of accuracy and reliability of operation, and furthermore, in terms of performance efficiency. It is an invention with industrial applicability as it exists.

Claims

A hybrid control unit for controlling driving of an engine and a motor, an engine control unit for controlling engine driving under control of the hybrid control unit, and a motor control unit for controlling motor driving under control of the hybrid control unit,
The engine control unit,
If the engine start and stop is repeated more than a predetermined time at the initial start of the engine set based on the engine idle time and the engine speed, it is determined as an engine output error due to poor engine combustion or instability.
The hybrid control unit,
Receiving the engine output error signal of the engine control unit engine output diagnostic apparatus, characterized in that it is provided to execute a preset lymph groove mode.

The method of claim 1, wherein the engine control unit,
Based on the respective signal values supplied from the front oxygen sensor installed at the front end of the catalyst and the rear oxygen sensor installed at the rear end, and the fuel injection amount during driving of the engine partial load set to the engine speed and the intake air amount when the engine is not started at the initial time. An engine output diagnosis apparatus for a hybrid vehicle, characterized in that it is provided to determine the engine output error according to the engine combustion failure.

The method of claim 1, wherein the engine control unit,
The engine output error is determined based on the engine combustion failure based on the engine speed, the elapsed time after the battery charging, the battery charge amount at the start of the battery charge, and the battery charge amount information, which is a difference between the battery charge amount at the present time. Engine output diagnostic apparatus for a hybrid vehicle, characterized in that it is provided to.

The method of claim 1, wherein the engine control unit,
And an engine output error based on a motor current amount during driving of an engine partial load set to an engine speed and an intake air amount when the engine start time is not at an initial time point.

In the engine output diagnostic method of a hybrid vehicle for diagnosing an engine output error due to an engine combustion failure based on the hybrid control unit that executes the engine driving control of the engine control unit and the motor driving control of the motor control unit,
A first engine that determines an engine output error due to an engine combustion failure when the engine start number and the predetermined number of times of engine start and engine start and stop are repeated at the initial start time of the engine set by the engine control unit based on engine idle time and engine speed; An engine output error determination step,
And a lymph groove execution step of executing a preset lymph groove mode in the case of an engine output error due to an engine combustion failure in the hybrid control unit.

According to claim 5, Engine output diagnostic method of the hybrid vehicle,
The engine control unit satisfies the first engine output diagnosis condition set based on the air-fuel ratio received during the engine partial load set from the engine speed and the intake air amount, the front oxygen sensor signal value and the rear oxygen sensor signal value of the catalyst system, and the fuel injection amount. And a second engine output error determining step of determining an engine output error according to the engine combustion failure.

The method of claim 6, wherein the second engine output error determination step,
When the engine speed is within a predetermined range, the air-fuel ratio during the engine partial load running in which the intake air amount is a predetermined amount or more is within a preset setting range, and the front oxygen sensor signal value is within the first predetermined range and is greater than the allowable value in the fuel injection amount The engine output diagnostic method of a hybrid vehicle, characterized in that it is provided to determine that the engine output error due to the engine combustion failure when the rear short sensor signal value is less than the second predetermined value.

According to claim 5, Engine output diagnostic method of the hybrid vehicle,
The engine speed at the time of battery charging while driving the engine in the engine controller is within a second predetermined range, the elapsed time after battery charging is equal to or greater than a predetermined threshold time, and the battery charge amount at the time of charge time and the battery charge amount at the present time. And when the vehicle battery charge amount information satisfies a second engine output diagnosis condition that is equal to or greater than a predetermined predetermined rate, determine the engine output error due to the engine combustion failure.

According to claim 5, Engine output diagnostic method of the hybrid vehicle,
When the engine speed is within a predetermined range and the engine current load satisfies the third engine output diagnosis condition when the current amount of the motor while driving the engine partial load with a predetermined amount or more is equal to or greater than a preset threshold, the engine output error according to the engine combustion failure is determined. Engine output diagnostic method for a hybrid vehicle, characterized in that provided.

The method of claim 5, wherein the lymph groove execution step,
Limit engine power with engine power torque derived based on remaining battery charge,
An engine output diagnosis method of a hybrid vehicle, characterized in that it is provided to control the driving by the engine drive stop and the power of the motor according to the limited engine output torque.

The method of claim 10, wherein the lymph groove execution step,
A method for diagnosing an engine output of a hybrid vehicle, characterized in that it is configured to execute one or more of driving and stopping of driving with a limited engine output torque and one of emergency light on and off according to the remaining battery charge amount.