RU2403420C1 - Method and system to control ice brake-decelerator - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: proposed method uses the value of at least one operating parametre selected to allow required braking moment. This method comprises determining required braking moment developed by the brake-decelerator and difference between required and developed braking moments. If said difference exceeds first tolerable value, brake-decelerator is controlled using the value of at least one second operating parametres. Second operating parametre is selected or adapted, or tuned to produce corrected developed braking torque. Developed braking moment is determined by actual or virtual braking moment transducer 3. First or second operating parametres are stored in memory in tabulated form. Operating parametres may be selected to the group of parametres including ICE exhaust system back pressure, supercharging pressure, pressure ahead or behind the turbine, turbine rpm or its variable geometry and position of vanes. In case difference between required and developed braking moment exceeds second tolerable value that exceeds first preset value, signal on fault is generated. Method of controlling is implemented by ICE brake-decelerator control system. Said control system comprises ICE control unit 12. Torque transducer 3 is mounted on ICE power transfer shaft 1a, 9, 10. ICE control unit 12 controls ICE operation and allows the control over brake-decelerator operation in compliance with selected control method. Said control unit 12 makes a part of transport facility control unit 14.

EFFECT: higher accuracy and reliability, optimum control.

11 cl, 2 dwg

Description

The invention relates to a method and a system for controlling the operation of a motor retarder of an internal combustion engine, intended primarily for use in heavy vehicles, such as trucks or buses. The invention also relates to an engine control unit for controlling the operation of an internal combustion engine in accordance with said method.

EP 1281841 discloses an engine compression brake system and a method for operating it, in which the electronic control unit changes the braking power of the brake system of an internal combustion engine based on a signal generated by a sensor for recording an operating mode, for example, vehicle loading, speed, tilt or pedal position. By adjusting the braking based on the vehicle’s need, significant noise reduction can be achieved.

One of the objectives of the present invention is to further improve the accuracy or efficiency, or the reliability of the engine retarder and the creation of a method and system for controlling the operation of such a brake in an optimal way.

Another objective of the present invention is to provide a method and system for controlling the operation of a retarder motor brake, in which the required braking torque can be obtained with greater accuracy.

The problem is solved in the claimed in paragraph 1 of the claims the method of controlling the operation of the motor retarder using the value of at least one operating parameter selected to obtain the required braking torque, which determines the magnitude of the braking torque developed by the motor retarder during vehicle braking means, and if the value of the difference between the magnitude of the required braking torque and the magnitude of the developed braking torque exceeds the first given nth limiting value, the operation of the retarder is controlled using the value of at least one second operating parameter, selected or adjusted so as to obtain an adjusted value of the braking torque.

The second working parameter can be an additional or alternative working parameter relative to the first working parameter, and it can be the same parameter as the first, but have a different value, the use of which leads, for example, to a more precise adjustment or selection, or adjustment.

In this description, the term "difference value" should be understood as a quantity without taking into account the sign, that is, regardless of whether a positive or negative value has this difference.

In addition, the objective of the invention is solved by the control system of the engine brake retarder, including the engine control unit, through which the above method is implemented.

One of the advantages of this solution is that the braking energy changes associated with changes, for example, ambient temperature, operating conditions, and manufacturing tolerances, can be minimized or compensated. Moreover, changes in braking energy caused by, for example, wear or a decrease in the performance of certain vehicle components, in particular a motor retarder, can also be compensated by using the method and system of this invention.

Another advantage of the present invention is that the method and system can also be used to monitor the operating parameters of the engine retarder and to detect malfunctions or diagnose the corresponding components of the internal combustion engine by evaluating the changes or the departure of these parameters.

In the dependent claims, preferred embodiments of the present invention are disclosed.

The embodiments of paragraphs 3-5 of the claims have the advantage that a self-learning and / or self-calibrating system can be implemented.

The embodiment of claim 7 has the advantage that a diagnostic and troubleshooting system can be implemented for the engine retarder.

Additional details, features and advantages of the present invention are disclosed in the following description, given as an example of preferred embodiments of the invention, illustrated by the drawings, which show:

figure 1 is a block diagram showing the main components of the system of the present invention; and

2 is a diagram and a more detailed block diagram of a system of the present invention and associated vehicle components.

1 schematically shows a vehicle control unit 14 or a retarder (retarder) control unit, or any other control unit included in a vehicle (such as a remote control unit, etc.), an engine control unit 12 including a first a program unit 121 and a second program unit 122, and a torque sensor 3 for detecting (recording) the actual braking torque generated or developed by the retarder of the internal combustion engine.

The vehicle control unit 14 is most often located in the driver's cab of the vehicle and performs the usual functions of regulating or controlling the components of the vehicle, and it usually also includes a retarder control unit. The engine control unit 12 is designed to control the internal combustion engine in a known manner.

The torque sensor 3 is preferably mounted on the vehicle’s transmission, for example between an internal combustion engine and a gearbox, or it can also be installed in other places, for example on a driveshaft or drive axle, or on any power-transmitting shaft of an internal combustion engine.

It is well known that, especially for heavy vehicles, such as trucks, the braking of the vehicle is accompanied or, under certain conditions, is entirely performed by turning on and controlling the engine retarder of the internal combustion engine.

This vehicle braking mode is initiated by the vehicle control unit 14 upon receipt of a braking command issued by the driver or automatically under certain circumstances or conditions, such as detecting a vehicle breakdown, exceeding a certain speed, etc.

Then, upon receipt of such a braking command, the vehicle unit 14 calculates the braking torque, which the engine retarder of the internal combustion engine must develop to completely stop or maintain the vehicle braking mode. This calculated braking torque is transmitted as a quantity or value X in Nm of the required braking torque to the engine control unit 12.

In the engine control unit 12, mainly in the first program unit 121, the obtained value of the required braking torque is estimated and the retarder of the internal combustion engine is activated, for example by activating the compression brake and (or) the mountain brake, by selecting at least one corresponding the first working parameter and changing its value in order to achieve the required value of the braking torque.

The compression brake can be activated, for example, by controlling the engine valves in such a way that a certain backward or counter-pressure gas is created in the cylinders during the compression stroke and (or) in the exhaust cycle, which acts against the movement of the pistons.

The mountain brake can be applied mainly in addition to the compression brake by closing to a predetermined or certain position (or force / pressure ratio) the damper (throttle) of the exhaust gas pressure regulator at the turbocharger turbine or any other damper that gives a specified transmission when installed in a certain position to create the selected back pressure in the exhaust system.

In general, the following (first and second) parameters and their values or values can be selected, adapted or adjusted to activate the mountain brake: boost pressure and its value (by adjusting the relief valve), pressure before and (or) after the turbine and its value (using, for example, a throttle installed before or after the turbine), the speed of the turbine and its value, the variable geometry of the turbine and its position, etc.

In order to obtain such a developed braking torque that is basically equal to the required braking torque, the first program unit contains a storage device in which the expected braking torque values are obtained for the group of the above parameters and their values (values), if you select the corresponding parameter and its value (value) and accordingly adjust or adjust the associated component of the internal combustion engine.

The expected braking torque values are preferably determined for a group of the above parameters and their values (values) once in an experiment with one or more test engines in the process of manufacturing a motor brake retarder and then stored in memory, for example, in the form of a table comparing these parameters and their values and each resulting braking torque value (that is, receive a set of engine data in the form of parameters and their values and corresponding braking torque values).

In the first program block 121, at least one suitable first working parameter is selected from this engine data and its value or value such that the resulting magnitude of the expected braking torque is basically equal to the magnitude of the required braking torque. Then, the engine control unit 12 adjusts or adjusts the corresponding components of the compression brake and / or mountain brake in accordance with at least one operating parameter and its value, as described above. At the same time, the selected at least one operating parameter and its value are transmitted together with the expected braking torque to the second program unit 122.

However, the usually developed braking torque obtained in reality by choosing the first parameter and its value may differ significantly from the expected (or required) braking torque due to manufacturing tolerances or certain external conditions, especially temperature or height, or due to wear that varies over time, and due to various combinations of other vehicle operating parameters, such as actual turbine speed, boost pressure, back pressure, etc.

In order to compensate for these effects and circumstances and to obtain a more exact match of the magnitude of the developed braking torque with the required braking torque, a torque sensor 3 has been introduced that records the value of the real or actually developed braking moment obtained when at least one first working parameter and its value are selected. Based on the registered value of the developed braking torque, an adjusted value of the braking torque developed by the engine retarder is generated.

If we consider in more detail, the recorded value of the braking torque is transmitted from the sensor 3 to the vehicle control unit 14. According to the first embodiment, the recorded braking torque value is compared with the desired value. If the value of the difference (regardless of the sign) between these values exceeds a predetermined value, the vehicle control unit 14 generates the required value for increasing or decreasing, respectively, the braking torque so as to reduce the specified value of the difference.

However, in accordance with the preferred second embodiment, the recorded braking torque value is transmitted to the engine control unit 12, where it is compared in the first program unit 121 with the braking torque value that was expected for the selected at least one first operating parameter and its value. Alternatively, the recorded braking torque value is compared with the braking torque value required by the vehicle control unit 14 (which is basically the same as explained above).

Preferably, this comparison is performed by the second program unit 122.

If the value of the difference between both values of the braking torque exceeds the first limit value, corrective actions are generated in such a way that a closed loop for regulating the braking torque developed by the motor retarder is created.

The correction of the developed braking torque can be performed using at least one second working parameter and its value, and the second parameter can be a variation of at least one (or more) of the selected first parameter, which consists mainly in increasing or decreasing at least one of the values at least one first parameter in predetermined steps in the second program unit 122, and then transmitting the changed (i.e., second) at least one parameter value in p the first program unit 121 (or to another appropriate part of the engine control unit 12) in order to regulate the respective components and generate, based on the changed at least one second parameter and its value, a new adjusted value of the developed braking torque.

Alternatively or in addition, at least one other operational parameter (and associated corresponding value) other than the first parameter can be selected mainly from the engine dataset and is used in the same way as the second parameter and its value.

The cyclic procedure can be repeated until the difference value (i.e., the difference value without taking into account the sign) between the actual value of the developed braking torque (registered by the torque sensor 3) and the braking torque required by the vehicle control unit 14 becomes less than the specified value the first limit value (for example, does not become approximately equal to zero).

2 schematically depicts some components of a vehicle, namely a driver’s cabin 4, front wheels 11a, rear wheels 11b, and an internal combustion engine 1. The output of the internal combustion engine 1 is connected via an intermediate shaft 1a to a gearbox 2, usually including a gear control unit 13 and driving the rear wheels 11b in a known manner through the driveshaft 9 and the drive axle 10.

The torque sensor 3 is integrated in the transmission of the vehicle, for example at the countershaft 1a. Alternatively, the torque sensor 3 may be located on the driveshaft 9 or on the drive axle 10, or also on any power transmission shaft of the internal combustion engine. In addition, either a real torque sensor or a virtual sensor can be used. Such a virtual sensor is described, for example, in US-PS 5771483.

The engine control unit 12 is designed to regulate the operation of the internal combustion engine 1. The internal combustion engine 1 comprises a suction manifold 8 with an input pressure sensor 15. The exhaust manifold 7 is connected to a turbine 5 of a turbocompressor having a constant or variable geometry.

The turbine of the turbocharger 5 has an exhaust pipe 5a, including a movable damper 6, which regulates the back pressure of the exhaust gases (in the case of variable geometry, the movable damper 6 is usually not needed). Preferably, the exhaust pressure sensor 16 is also disposed in the exhaust pipe 5a. In addition, as is known, the turbine of the turbocharger 5 has an air inlet channel 5b and an outlet channel 5 for supplying compressed air to the intake manifold 8 of the internal combustion engine 1.

Finally, the vehicle control unit 14, including the retarder control unit, is located in the cabin 4.

When the driver activates the brake pedal or releases the gas pedal, or activates the brake switch (if the braking command is generated automatically depending on the specific conditions or condition of the vehicle), the vehicle control unit 14 determines which of the available sources of braking energy (main Thus, wheel brakes and motor brakes) must generate this energy or braking torque and its magnitude. This decision is again made on the basis of certain conditions, the condition of the vehicle and the amount of total generated braking energy, for example, on the basis of how much the brake pedal is engaged by the driver.

The amount of braking energy to be generated by the internal combustion engine 1 is transmitted to the engine control unit 12 in the form of the required braking torque. As discussed above in connection with FIG. 1, the first program unit 121 selects from the stored engine data set at least one operating parameter and its value, which in accordance with the stored engine data set will produce a result corresponding to the required braking torque.

Then, the selected at least one parameter and its value is realized, for example, by moving the blades of the turbocharger with variable geometry to the corresponding position and (or) closing the valve 6 in the exhaust pipe 5a of the turbine 5 of the turbocharger (in accordance with the stored data) to create a braking moment using an internal combustion engine 1.

The actual value of the developed braking torque applied, for example, to the countershaft 1a, is detected by the braking torque sensor 3 and transmitted to the second program unit 122 and to the vehicle control unit 14.

In the second program unit 122, the actual magnitude of the developed braking torque is compared with the expected (or required) magnitude of the braking torque, as described above. If the difference value between them exceeds a certain or predetermined first limit value, the second program unit 122 changes in accordance with the first alternative embodiment, at least one value of the first operating parameter that was used by the first program unit 121, and transmits this at least one value to as at least one second parameter value to the first program unit 121 (or to another part of the engine control unit 12), so that it again adjusts the corresponding motor components of the combustion engine 1 to obtain an adjusted value of the developed braking torque.

In a second alternative embodiment, another operational parameter other than at least one first operational parameter may be selected as an alternative or in addition to at least one second parameter (and its value) in the same manner as shown above.

Then, the braking torque is registered again by the torque sensor 3, and the registered braking torque is transmitted again to the second program unit 122. If the difference between the real braking torque and the expected or required braking torque still exceeds a predetermined first limit value (for example, a value of zero) the cyclic procedure is repeated.

In addition to this, a closed loop is arranged so that the actual braking torque can be made at least substantially equal to the braking torque required by the vehicle control unit 14.

In addition, the method can be implemented as a continuous process, in which, if, for example, the speed of the engine changes, the selected parameter also changes depending on the speed of the engine.

This method and system have the following additional advantages.

By presenting to the vehicle control side 14 the value of the actually developed braking torque (measured by the sensor 3) instead of the expected braking torque represented by the first program unit 121, the situation is prevented when, in the event of a failure of the engine retarder, the braking torque is taken into account by the vehicle control unit 14 means, although in reality it does not affect the braking of the vehicle.

In addition, the engine diagnostic system can be implemented or improved if the difference between the value of the actually developed braking torque and the expected value of the braking torque exceeds a predetermined second limit value that is greater than the first limit value, as this may indicate that the corresponding components engine, which were adjusted based on the selected parameters, have a defect or their performance is impaired.

Moreover, a self-learning and self-calibrating system can be implemented if both the parameter value and (or) the value of the expected braking torque (which are stored in the engine data set) are adjusted in the engine data set in accordance with the difference between the value of the actually developed braking torque and the value of the expected braking torque, so that for the next vehicle braking cycle, the developed braking torque will more accurately coincide with the required braking torque, and there will be a need A smaller number of corrective actions is possible or they will not be required at all.

In addition, the method and system of the present invention may be particularly applicable to compensate for changes in braking energy that occur, for example, due to wear over time or a decrease in the operability of components of a motor retarder or other components of a vehicle.

In addition, the method and the corresponding system have the advantage that not only is the increase in the braking distance accuracy achieved, but also the accuracy of the system components associated with the creation of the braking torque obtained from the engine. An example would be a motor brake system, which is used in combination or instead of other brakes, such as, for example, wheel brakes, or in the case of a combination of wheel brakes, a motor brake and an additional retarder brake. The increased accuracy of the method of the present invention will make controlling such a braking system easier and increase driver comfort.

Finally, the braking torque can be measured using a torque sensor 3 integrated in the transmission with much greater accuracy and reliability than using some other sensors inserted into the internal combustion engine, such as, for example, a pressure sensor in a drive turbine (i.e. a pressure measurement sensor installed between the turbine outlet and the damper) or a pressure or pressure and temperature sensor installed in the exhaust manifold or after the turbine, since these sensors are usually in harsh conditions, which Some determine the possibility of their clogging or even failure, so that they can no longer correctly register the corresponding values. Moreover, using these incorrect sensor readings, it is possible, for example, to establish a significantly higher back pressure, which can lead to a loss in the strength characteristics of the fuel injector nozzles.

Claims (11)

1. A method for controlling the operation of a motor retarder of an internal combustion engine using the value of at least one operating parameter selected to obtain the required braking torque, including the step at which the magnitude of the braking torque developed by the retarder during vehicle braking is determined, and if the difference value between the magnitude of the required braking torque and the magnitude of the developed braking torque exceeds the first predetermined limit value; adjusting the operation of the retarder using the value of at least one second working parameter, selectable, or adaptable, or adjustable so as to obtain an adjusted value of the braking torque. 2. The method according to claim 1, in which the magnitude of the braking torque developed by the engine retarder is determined using a real or virtual braking torque sensor. 3. The method according to claim 1, in which the group of the first operating parameters is stored in the storage device in the form of a table of correspondence to each parameter value of the expected braking torque value obtained by controlling the operation of the retarder using the corresponding parameter value. 4. The method according to claim 1, in which the value of the second working parameter is determined by the value of the first working parameter by increasing or decreasing it by at least one predetermined step. 5. The method according to claim 4, in which the value of the second working parameter is stored in the table in the memory instead of the value of the first working parameter. 6. The method according to claim 1, in which at least one first and (or) at least one second working parameter and its value are selected from the group of parameters and parameter values, respectively, including back pressure and its value in the exhaust system of an internal combustion engine, boost pressure and its value, pressure before and (or) after the turbine and its value, turbine speed and its value, variable turbine geometry and position of its blades. 7. The method according to claim 1, in which a signal about a malfunctioning state is obtained if the difference between the magnitude of the required braking torque and the magnitude of the developed braking torque exceeds a predetermined second limit value that is greater than a first predetermined limit value. 8. A system for controlling the operation of a motor retarder of an internal combustion engine, comprising an engine control unit (12) for implementing the method in accordance with at least one of claims 1 to 7. 9. The system of claim 8, in which the braking torque is determined using at least one real or virtual torque sensor (3) mounted on the power transmitting shaft (1a, 9, 10) of the internal combustion engine (1). 10. An engine control unit (12) for controlling an internal combustion engine (1) and controlling the operation of the engine retarder according to the method in accordance with at least one of claims 1 to 7. 11. The control unit (12) according to claim 10, which is a part of the vehicle control unit (14).

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