JP2011163182A - Control device of vehicle driving unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain, when torque including an oscillating component is demanded for specific vehicle control and an efficient demand is also made for vehicle control other than the specific vehicle control, torque and efficiency according to the demands without fluttering a throttle. <P>SOLUTION: Model torque for the specific vehicle control is generated in conjunction with the generation of specific demand torque including the oscillating component, and the ratio of the specific demand torque to the model torque is calculated as specific demand efficiency. A value obtained by multiplying the specific demand efficiency by other demand efficiency is calculated as total demand efficiency. Then, demand potential torque obtained by dividing the specific demand torque by the total demand efficiency is converted to a cylinder air amount necessary for its attainment, and an opening degree command value to the throttle is determined based on the cylinder air amount. Further, estimated potential torque when the throttle is operated according to the opening degree command value is calculated, and ignition timing is determined using a ratio of the specific demand torque to the estimated potential torque as indicated efficiency. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a control device for a vehicle drive unit including an internal combustion engine as a power unit.

  As one method for controlling a vehicle drive unit including an internal combustion engine, for example, as disclosed in Japanese Patent Application Laid-Open No. 2009-047102, a method is known in which the operation amount of each actuator is determined using efficiency as a control amount together with torque. ing. Efficiency here means the ratio of the torque actually output to the potential torque that can be output by the internal combustion engine. When this efficiency is less than 1, a margin is generated between the latent torque and the actual output torque, and the energy corresponding to the margin is output from the internal combustion engine in a form other than the torque. A typical example is the internal energy of the exhaust gas, and the temperature of the exhaust gas can be raised by reducing the efficiency. This can be used for raising the temperature of the catalyst. Ignition timing can be used as a means for controlling the efficiency. The greater the retard amount based on the MBT of the ignition timing, the lower the efficiency and the greater the margin between the latent torque and the actual output torque. Since the torque response to the ignition timing operation is better than that to the throttle operation, it is possible to meet the emergency torque demand by setting the efficiency low and securing the above margin as the reserve torque. It becomes possible to respond.

  There are demands from various viewpoints on the torque and efficiency as the controlled variable. In the case of torque, there are required torque for satisfying the driver's acceleration request, required torque for drive control such as skid prevention, and the like. In the case of efficiency, there are required efficiency for warming up the catalyst, required efficiency for ensuring reserve torque, and the like. The default for each required efficiency is 1, and the greater the requirement, the smaller the efficiency value is. In the control device (hereinafter referred to as the preceding device) described in the aforementioned patent publication, when there are a plurality of requests for one control amount in this way, the final required control amount is determined by arbitration. . Arbitration here is a calculation process for obtaining one numerical value from a plurality of numerical values performed in accordance with a predetermined rule. Specific calculation rules include maximum value selection, minimum value selection, averaging, or superposition.

JP 2009-047102 A JP 2009-162198 A JP 2009-047100 A JP 2009-162185 A JP 2008-280984 A

  The torque required to be output from the internal combustion engine includes a required torque for idle speed control (hereinafter referred to as ISC required torque). In the idle speed control, a deviation between the target idle speed and the actual speed is fed back to the ISC required torque so that the speed of the internal combustion engine becomes a predetermined target idle speed. For this reason, the ISC required torque may include a vibration component having a relatively high frequency.

  In the above-described prior art, the required torque is divided by the required efficiency to be raised, and the throttle opening is calculated from the raised request torque converted into an air amount. For this reason, when the ISC required torque including the high frequency component is converted into the air amount as it is, the throttle opening calculated based on it is also vibrated. When the throttle is operated with the vibration throttle opening as the operation amount, the operation amount increases due to the fluttering of the throttle, and as a result, the durability of the throttle is deteriorated.

  As a countermeasure against such a problem, a required efficiency having the same vibration component as the ISC required torque (hereinafter referred to as ISC required efficiency) is generated, and each manipulated variable is calculated using the ISC required torque and the ISC required efficiency. It is valid. By dividing the ISC required torque by the ISC required efficiency having the same vibration component, the high frequency component included in the ISC required torque is canceled. As a result, the throttle opening is calculated based on the amount of air that does not have a high frequency component, and fluttering of the throttle due to the influence of the high frequency component is prevented.

  However, the efficiency required as the control amount of the internal combustion engine is not limited to the ISC required efficiency. For example, at the time of cold start of the internal combustion engine, the required efficiency for catalyst warm-up (hereinafter referred to as catalyst warm-up required efficiency) may exist alongside the ISC required efficiency. In this case, according to the above-described prior art, arbitration between the ISC required efficiency and the catalyst warm-up required efficiency is performed by selecting the minimum value, and the selected one is reflected in the calculation of the throttle opening as the final required efficiency. It will be. When the catalyst warm-up required efficiency is selected as the final required efficiency, there is no vibration component that cancels the high frequency component of the ISC required torque. For this reason, the throttle opening calculated as the operation amount becomes vibrational, and the fluttering of the throttle occurs.

  The present invention has been made in view of the above-described problems, and relates to a control device for a vehicle drive unit, which requires torque including a vibration component for specific vehicle control, and for vehicle control other than specific vehicle control. In the case where there are other efficiency requirements, the object is to realize torque and efficiency in accordance with those requirements without fluttering the throttle.

In order to achieve the above object, a control device for a vehicle drive unit according to a first invention comprises:
The ratio of the torque output by the internal combustion engine and the ratio of the torque actually output to the potential torque that can be output by the internal combustion engine (hereinafter referred to as efficiency) is used as a control amount, and the throttle opening and ignition timing are used as operation amounts. In a control device for a vehicle drive unit that controls the operation of an internal combustion engine,
Request torque generating means for generating a request torque including a vibration component for specific vehicle control (hereinafter referred to as a specific request torque);
Model torque generating means for generating a model torque for the specific vehicle control in conjunction with the generation of the specific required torque;
Specific required efficiency calculating means for calculating a ratio of the specific required torque to the model torque as specific required efficiency;
Required efficiency generating means for generating required efficiency (hereinafter referred to as other required efficiency) for vehicle control other than the specific vehicle control;
A total required efficiency calculating means for calculating a value obtained by multiplying the specific required efficiency by the other required efficiency as an overall required efficiency;
Required latent torque calculating means for calculating required latent torque by dividing the required torque by the total required efficiency;
A required in-cylinder air amount calculating means for calculating an in-cylinder air amount (hereinafter referred to as a required in-cylinder air amount) necessary for realizing the required latent torque;
An opening command value determining means for determining an opening command value for the throttle based on the required in-cylinder air amount;
Estimated latent torque calculating means for calculating an estimated latent torque when the throttle is operated according to the opening command value;
Estimated efficiency calculating means for calculating a ratio of the required torque to the estimated latent torque (hereinafter, estimated efficiency);
Ignition timing determining means for determining an ignition timing for realizing the required torque using the estimated efficiency as an instruction efficiency;
It is characterized by having.

  According to a second aspect of the present invention, there is provided the vehicle drive unit control apparatus according to the first aspect, wherein the specific vehicle control is idle speed control performed during idle operation, and other than the specific vehicle control. This vehicle control includes exhaust temperature control for warming up the catalyst.

  According to the control device for a vehicle drive unit of the first invention, the vibration component included in the specific required torque is reflected in the specific required efficiency calculated as the ratio between the specific required torque and the model torque, and further the specific required efficiency. This is reflected in the total required efficiency obtained by multiplying the other required efficiency. Therefore, the vibration component included in the specific required torque is removed from the required latent torque obtained by dividing the specific required torque by the total required efficiency. Thereby, the opening command value calculated based on the required latent torque becomes stable without vibration, and fluttering of the throttle when the throttle is operated according to the opening command value is prevented. The instruction efficiency that is the basis for calculating the ignition timing is the ratio of the specific required torque to the estimated potential torque when the throttle is operated in accordance with the opening command value. In the steady state, the specific required efficiency and other required efficiencies This is consistent with the overall required efficiency, which is the product of Accordingly, the throttle is operated according to the opening command value and the ignition timing is operated according to the indicated efficiency, so that the torque and the efficiency that meet the requirements are simultaneously realized.

  According to the control device for a vehicle drive unit of the second aspect of the invention, it is possible to perform the idle speed control and the exhaust temperature control for warming up the catalyst in parallel without flapping the throttle.

It is a block diagram which shows the structure of the control apparatus of the vehicle drive unit of embodiment of this invention.

  An embodiment of the present invention will be described with reference to FIG.

  The internal combustion engine to be controlled in the present embodiment is a spark ignition type four-cycle reciprocating engine. The control device for the vehicle drive unit controls the operation of the internal combustion engine by operating the throttle and the ignition device. The operation amount of the throttle by the control device is the throttle opening, and the operation amount of the ignition device is the ignition timing. The control device outputs a command value of each manipulated variable to the internal combustion engine, that is, an opening command value and an ignition timing command value.

  FIG. 1 is a block diagram showing a configuration of a control device for a vehicle drive unit according to an embodiment of the present invention. The control device of the present embodiment includes an ISC function unit 2 for performing idle speed control. The ISC function unit 2 is provided with an ISC required torque generating unit 4 that generates an ISC required torque, an ISC basic torque generating unit 6, and an ISC required efficiency calculating unit 8.

  The ISC required torque generating unit 4 adjusts the ISC required torque by feedback control so that the rotational speed of the internal combustion engine becomes the target rotational speed during idling of the vehicle. Therefore, as shown in the waveform in FIG. 1, the ISC required torque output from the ISC required torque generating unit 4 includes a high frequency component.

  The model torque generator 6 generates a model torque for idle speed control in conjunction with the generation of the ISC request torque by the ISC request torque generator 4. The model torque is an allowable maximum torque when it is assumed that the catalyst warm-up required efficiency and the other required efficiency described later are both 1. As shown in the waveform in FIG. 1, this model torque does not include a vibration component.

  The ISC required efficiency calculation unit 8 calculates the ratio of the ISC required torque to the model torque as the ISC required efficiency. The obtained ISC required efficiency includes high frequency components similar to the high frequency components included in the ISC required torque, as shown by the waveform in FIG.

  The ISC function unit 2 outputs the ISC request torque generated by the ISC request torque generation unit 4 and the ISC request efficiency calculated by the ISC request efficiency calculation unit 8 as a required control amount for idle speed control. However, the default of the ISC request efficiency that is output is 1, and only when the ISC request efficiency calculation unit 8 calculates the ISC request efficiency, the calculated value is output as the ISC request efficiency. Therefore, when the idle operation is not performed, the ISC required torque output from the ISC function unit 2 is zero, and the output ISC required efficiency is 1.

  The ISC required torque output from the ISC function unit 2 is input to the target torque calculation unit 14. In addition to the ISC required torque, various types of required torque such as a driver required torque are input to the target torque calculation unit 14. The target torque calculation unit 14 arbitrates various types of input requested torque, and calculates the arbitration result as the target torque. However, during idle driving in which the vehicle is in a non-running state, driver-requested torque and other required torque are not generated, and only the ISC required torque is input to the target torque calculation unit 14. For this reason, during idle operation, the ISC required torque is directly output from the target torque calculation unit 14 as the target torque.

  The ISC required efficiency output from the ISC function unit 2 is input to the target efficiency calculation unit 16. The required efficiency input to the target efficiency calculation unit 16 includes the required efficiency from the catalyst warm-up function unit 10 in addition to the ISC required efficiency. When the catalyst temperature is expected to be low, such as during cold start, the catalyst warm-up function unit 10 increases the exhaust heat from the internal combustion engine by requiring efficiency less than 1, thereby Promote warm-up. The target efficiency calculation unit 16 mediates various types of required efficiency including the ISC required efficiency and the catalyst warm-up required efficiency, and calculates the total required efficiency that is the arbitration result as the target efficiency.

  The arbitration method in the target efficiency calculation unit 16, that is, the calculation rule for the arbitration is one feature in the present embodiment. The target efficiency calculation unit 16 multiplies all the collected required efficiencies and calculates the product as the target efficiency. For this reason, during idle operation, when there is no request other than the ISC request, all the request efficiencies other than the ISC request efficiency are 1, so that the ISC request efficiency is directly output from the target efficiency calculation unit 16 as the target efficiency. The On the other hand, when there is a catalyst warm-up request in parallel with the ISC request, the product of the ISC request efficiency and the catalyst warm-up request efficiency is output from the target efficiency calculation unit 16 as the target efficiency. In any case, as shown by the waveform in FIG. 1, the target efficiency includes high frequency components similar to the ISC required efficiency.

  The target torque and target efficiency determined as described above are input to the target MBT torque calculation unit 18. The target MBT torque calculation unit 18 obtains the target MBT torque by dividing the target torque by the target efficiency. The target MBT torque is a target value of the output torque on the assumption that the ignition timing is MBT, and is the above-described required value of the latent torque, that is, the required potential torque.

When the target torque is the ISC required torque, the high frequency component included therein is canceled by division by the target efficiency including the same high frequency component. This point will be specifically described using equations. First, as indicated by symbols in FIG. 1, the ISC required torque is A, the model torque is B, the ISC required efficiency is C, the catalyst warm-up required efficiency is D, the target efficiency is E, and the target MBT torque is Indicated as F. Then, when there is no catalyst warm-up request, that is, when the catalyst warm-up request efficiency D = 1, the target MBT torque can be expressed by the following equation (1). On the other hand, when there is a catalyst warm-up request, that is, when the catalyst warm-up request efficiency D <1, the target MBT torque can be expressed by the following equation (2).
F = A / E = A / C = B (1)
F = A / E = A / (C × D) = B / D (2)

  As shown in Equation (1), when there is no catalyst warm-up request, the target MBT torque matches the model torque that does not have a high frequency component. When there is a catalyst warm-up request, the target MBT torque matches the value obtained by dividing the model torque by the catalyst warm-up request efficiency, as shown in equation (2). That is, according to the control device of the present embodiment, as shown in the waveform in FIG. 1, the high frequency component included in the ISC required torque is removed from the target MBT torque.

  The target MBT torque is converted into a cylinder air amount (or charging efficiency) value in the cylinder air amount calculation unit 20. The in-cylinder air amount calculation unit 20 uses a map for converting torque into an in-cylinder air amount. This map is a map in which the torque and the in-cylinder air amount are associated with various engine information as keys on the assumption that the ignition timing is MBT. Here, the in-cylinder air amount necessary for realizing the target MBT torque that is the required latent torque, that is, the required in-cylinder air amount is calculated.

  Next, the throttle opening calculation unit 22 converts the required in-cylinder air amount into a throttle opening command value. An inverse model of the air model (air inverse model) is used for the conversion. The air model is a physical model of the intake system in which the response of the in-cylinder air amount to the operation of the throttle is modeled based on fluid dynamics. The throttle opening calculated by the inverse model is a throttle opening required to achieve the required in-cylinder air amount, and the control device outputs the throttle opening as an opening command value to the throttle. As shown in the waveform in FIG. 1, the opening command value calculated based on the target MBT torque is stable without vibration. This prevents fluttering of the throttle when the throttle is operated according to the opening command value.

  In the control device of the present embodiment, in parallel with the above processing, the estimated MBT torque calculation unit 24 calculates the estimated MBT torque based on the actual throttle opening. The estimated MBT torque is an estimated torque when the ignition timing is assumed to be MBT, and this means a torque (estimated latent torque) that the internal combustion engine can potentially output under the current throttle opening. A map is used to calculate the estimated MBT torque. This map is a map in which the torque and the air amount are associated with various engine information as a key on the assumption that the ignition timing is MBT.

  The estimated MBT torque is input to the torque efficiency calculation unit 26 together with the replicated target torque. In the torque efficiency calculation unit 26, the ratio of the target torque to the estimated MBT torque is calculated as the torque efficiency. The torque efficiency is an estimated efficiency when the ignition device is operated so as to achieve the target torque under the current throttle opening, and coincides with the target efficiency in a steady state. For this reason, as shown by the waveform in FIG. 1, the torque efficiency includes a high frequency component similar to the target efficiency.

  The torque efficiency calculated by the torque efficiency calculation unit 26 is input to the ignition timing calculation unit 28 as instruction efficiency. The ignition timing calculation unit 28 calculates an ignition timing for realizing the target torque based on the instruction efficiency. For the calculation, a map in which the instruction efficiency and the ignition timing are associated with each other using various engine information as a key is used. In this map, the retard amount from the MBT of the ignition timing is increased as the instruction efficiency is smaller than 1. The ignition timing calculation unit 28 outputs the calculated value to the ignition device as an ignition timing command value. Since the ignition device has no response delay in response to a command signal such as a throttle, even when a high-frequency ignition timing command value having a waveform shown in FIG. Is performed. Thereby, the target torque and efficiency are realized at the same time.

  As described above, according to the control device of the present embodiment, the idle speed control and the exhaust temperature control for warming up the catalyst can be performed in parallel without flapping the throttle.

2 ISC function unit 4 ISC required torque generating unit 6 Model torque generating unit 8 ISC required torque calculating unit 10 Catalyst warm-up function unit 14 Target torque calculating unit 16 Target efficiency calculating unit 18 Target MBT torque calculating unit 20 In-cylinder air amount calculating unit 22 Throttle opening calculator 24 Estimated MBT torque calculator 26 Torque efficiency calculator 28 Ignition timing calculator

Claims (2)

The ratio of the torque output by the internal combustion engine and the ratio of the torque actually output to the potential torque that can be output by the internal combustion engine (hereinafter referred to as efficiency) is used as a control amount, and the throttle opening and ignition timing are used as operation amounts. In a control device for a vehicle drive unit that controls the operation of an internal combustion engine,
Request torque generating means for generating a request torque including a vibration component for specific vehicle control (hereinafter referred to as a specific request torque);
Model torque generating means for generating a model torque for the specific vehicle control in conjunction with the generation of the specific required torque;
Specific required efficiency calculating means for calculating a ratio of the specific required torque to the model torque as specific required efficiency;
Required efficiency generating means for generating required efficiency (hereinafter referred to as other required efficiency) for vehicle control other than the specific vehicle control;
A total required efficiency calculating means for calculating a value obtained by multiplying the specific required efficiency by the other required efficiency as an overall required efficiency;
Required latent torque calculating means for calculating required latent torque by dividing the specific required torque by the total required efficiency;
A required in-cylinder air amount calculating means for calculating an in-cylinder air amount (hereinafter referred to as a required in-cylinder air amount) necessary for realizing the required latent torque;
An opening command value determining means for determining an opening command value for the throttle based on the required in-cylinder air amount;
Estimated latent torque calculating means for calculating an estimated latent torque when the throttle is operated according to the opening command value;
Estimated efficiency calculating means for calculating a ratio of the specific required torque to the estimated potential torque (hereinafter, estimated efficiency);
Ignition timing determination means for determining an ignition timing for realizing the specific required torque using the estimated efficiency as an instruction efficiency;
A control device for a vehicle drive unit comprising:   The specific vehicle control is idle speed control performed during idle operation, and vehicle control other than the specific vehicle control includes exhaust temperature control for warming up the catalyst. Control device for vehicle drive unit.

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