CN109356737A - Method and system for controlling a multi-cylinder engine - Google Patents

Abstract

This application provides a kind of control method of multicylinder engine and system, which includes: master controller, from controller, the multicylinder engine with n cylinder and the phase detector connecting with master controller；Master controller, for judging the control main body of cylinder to be sprayed in multicylinder engine；When controlling main body is master controller, the nozzle parameter of the cylinder to be sprayed is calculated by phase detector, and control cylinder to be sprayed according to nozzle parameter and sprayed；When control main body be it is described from controller when, the nozzle parameter of cylinder to be sprayed is calculated by phase detector, and nozzle parameter is sent to from controller；From controller, sprayed for controlling cylinder to be sprayed according to nozzle parameter.The control system solves master controller in the prior art and is to carry out injection phase differentiation according to respective phase detector from controller, it may appear that the problem of difference occurs in the phase angle respectively differentiated.

Description

Method and system for controlling a multi-cylinder engine

technical field

The present invention relates to the technical field of engine control, and more particularly, to a control method and system for a multi-cylinder engine.

Background technique

Based on the multi-cylinder engine, the control method is mainly controlled by the master controller and the slave controller to coordinate the injection of the multi-cylinder engine.

However, at present, the master controller and the slave controller discriminate the injection phase according to their respective phase sensors, so that there will be differences in the phase angles of their respective determinations. For example, the master controller determines that the current cylinder is 1 cylinder, and the slave controller determines the current cylinder. The cylinder is 2 cylinders, which causes the actual injection of the multi-cylinder engine to be abnormal, ranging from rotational speed fluctuations to serious cylinder pulling and other failures.

SUMMARY OF THE INVENTION

In view of this, in order to solve the above problems, the present invention provides a control method and system for a multi-cylinder engine, and the technical solutions are as follows:

A control system for a multi-cylinder engine, the control system comprising: a master controller, a slave controller, a multi-cylinder engine with n cylinders, and a phase sensor connected to the master controller;

The main controller is used to determine the control subject of the cylinder to be injected in the multi-cylinder engine; when the control subject is the main controller, the phase sensor is used to calculate the injection parameter of the cylinder to be injected, and control the cylinder to be injected according to the injection parameter to perform injection; when the control subject is the slave controller, calculate the injection parameter of the cylinder to be injected through the phase sensor, and send the injection parameter to the slave controller;

The slave controller is configured to control the cylinder to be injected to perform injection according to the injection parameter.

Preferably, the main controller for calculating the injection parameter of the cylinder to be injected through the phase sensor and controlling the injection cylinder to perform injection according to the injection parameter is specifically used for:

Entering the power-on state, and triggering a phase interruption signal to calculate the injection parameter of the cylinder to be injected through the phase sensor; control the cylinder to be injected to perform injection according to the injection parameter.

Preferably, the phase sensor is used to calculate the injection parameters of the cylinder to be injected, and send the injection parameters to the master controller of the slave controller, specifically for:

Enter the power-on state, and at the same time make the slave controller enter the power-on state, and start timing at the same time;

triggering a phase interruption signal to calculate the injection parameter of the cylinder to be injected and the first delayed injection time through the phase sensor;

After the calculation is completed, send the injection parameters, the first delayed injection time and the current master timing time of the master controller to the slave controller;

The slave controller for controlling the injection cylinder to perform injection according to the injection parameter is specifically used for:

When receiving the injection parameter, the first delayed injection time and the master timing time, record the current slave timing time of the slave controller;

calculating a second delayed injection time according to the master timing time, the slave timing time and the first delayed injection time;

According to the injection parameter, after waiting for the second delayed injection time, the cylinder to be injected is controlled to perform injection.

Preferably, the slave controller for calculating the second delayed injection time according to the master timing time, the slave timing time and the first delayed injection time is specifically used for:

subtracting the master timing time from the slave timing time to obtain a third delayed injection time;

The second delayed injection time is obtained by subtracting the third delayed injection time from the first delayed injection time.

Preferably, the injection parameters include: phase angle, fuel injection amount, power-on time, advance angle and TDC angle of the cylinder to be injected.

A control method for a multi-cylinder engine, characterized in that it is applied to the main controller in any of the above control systems, the control method comprising:

judging the control subject of the cylinder to be injected in the multi-cylinder engine;

When the control subject is the main controller, the phase sensor is used to calculate the injection parameter of the cylinder to be injected, and the cylinder to be injected is controlled to perform injection according to the injection parameter;

When the control subject is the slave controller, the phase sensor calculates the injection parameters of the cylinder to be injected, and sends the injection parameters to the slave controller, so that the slave controller can follow the The injection parameter controls the cylinder to be injected to perform injection.

Preferably, calculating the injection parameter of the cylinder to be injected by the phase sensor, and controlling the cylinder to be injected to perform injection according to the injection parameter, includes:

Entering the power-on state and triggering the phase interrupt signal to calculate the injection parameter of the cylinder to be injected through the phase sensor;

The cylinder to be injected is controlled to perform injection according to the injection parameter.

Preferably, the phase sensor calculates the injection parameters of the cylinder to be injected, and sends the injection parameters to the slave controller, so that the slave controller controls the cylinder to be injected according to the injection parameters The injection cylinder performs injection, including:

Enter the power-on state, and at the same time make the slave controller enter the power-on state, and start timing at the same time;

triggering a phase interruption signal to calculate the injection parameter of the cylinder to be injected and the first delayed injection time through the phase sensor;

After the calculation is completed, the injection parameters, the first delayed injection time and the current master timing time of the master controller are sent to the slave controller, so that the slave controller receives the In the case of injection parameters, the first delayed injection time and the master timing time, the current slave timing time of the slave controller is recorded, and the slave controller is also made according to the master timing time, the slave timing time and the first delayed injection time, calculate the second delayed injection time, and also make the slave controller control the cylinder to be injected after waiting for the second delayed injection time according to the injection parameters. injection.

Preferably, the second delay injection time is calculated by the slave controller according to the master timing time, the slave timing time and the first delayed injection time, including:

subtracting the master timing time from the slave timing time to obtain a third delayed injection time;

The second delayed injection time is obtained by subtracting the third delayed injection time from the first delayed injection time.

Preferably, the injection parameters include: phase angle, fuel injection amount, power-on time, advance angle and TDC angle of the cylinder to be injected.

Compared with the prior art, the beneficial effects realized by the present invention are:

In the control system of the multi-cylinder engine, whether the main controller controls the cylinder to be injected for injection or the slave controller controls the cylinder to be injected for injection, the injection parameters are calculated by the main controller based on a phase sensor, that is, the main controller and the slave controller to control the injection of the cylinder to be injected all rely on the reference of the phase information calculated by the master controller and the phase sensor, which also solves the problem that the master controller and the slave controller in the prior art are based on their respective phase sensors. When the injection phase is discriminated, there is a problem in that the phase angles of the respective discriminants are different.

In addition, compared with the control system in the prior art, the control system of the multi-cylinder engine reduces one phase sensor, the structure becomes simpler, and the production cost is also reduced.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only It is an embodiment of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to the provided drawings without creative work.

1 is a schematic structural diagram of a control system for a multi-cylinder engine provided by an embodiment of the present invention;

2 is a schematic flowchart of a control method for a multi-cylinder engine provided by an embodiment of the present invention;

3 is a schematic flowchart of a main controller controlling a cylinder to be injected according to an embodiment of the present invention;

4 is a schematic flowchart of a master controller and a slave controller controlling a cylinder to be injected according to an embodiment of the present invention;

FIG. 5 is another schematic flowchart of a master controller and a slave controller controlling a cylinder to be injected according to an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

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

Referring to FIG. 1, FIG. 1 is a schematic structural diagram of a control system for a multi-cylinder engine provided by an embodiment of the present invention, the control system includes: a master controller, a slave controller, a multi-cylinder engine with n cylinders, and a multi-cylinder engine with the master controller. The phase sensor connected to the controller, where n is a positive integer greater than 1;

The main controller is used to determine the control subject of the cylinder to be injected in the multi-cylinder engine; when the control subject is the main controller, the phase sensor is used to calculate the injection parameter of the cylinder to be injected, and control the cylinder to be injected according to the injection parameter to perform injection; when the control subject is the slave controller, calculate the injection parameter of the cylinder to be injected through the phase sensor, and send the injection parameter to the slave controller;

The slave controller is configured to control the cylinder to be injected to perform injection according to the injection parameter.

In this embodiment, whether the master controller controls the cylinder to be injected or the slave controller controls the cylinder to be injected, the corresponding injection parameters are calculated by the master controller through the phase sensor connected to it. That is to say, both the master controller controlling the cylinder to be injected and the slave controller controlling the cylinder to be injected have the same reference, which is the phase reference calculated by the master controller through the phase sensor. This also solves the problem that the master controller and the slave controller in the prior art discriminate the injection phase according to their respective phase sensors, and the phase angles of the respective discriminators are different.

It should be noted that, in this embodiment, the phase sensor is provided on the multi-cylinder engine, which includes but is not limited to a crankshaft sensor and a camshaft sensor. The injection parameters include but are not limited to the phase angle, fuel injection amount, power-on time, advance angle and TDC (Top Dead Center) angle of the cylinder to be injected, as well as the engine speed and other parameters information.

Further, in this embodiment, it is obvious that there are two control subjects for the cylinders to be injected in the multi-cylinder engine, one is controlled by the master controller, and the other is controlled by the slave controller. The principle of this control method is described in detail.

Method 1: When the control subject is the main controller, the phase sensor is used to calculate the injection parameters of the cylinder to be injected, and the specific principles of controlling the cylinder to be injected according to the injection parameters are as follows:

First, the main controller needs to enter the power-on state, that is, power on the main controller;

After the power-on is completed, a phase interruption signal is triggered in the main controller, so that the main controller calculates the injection parameters of the cylinder to be injected through the phase sensor;

After the calculation is completed, including but not limited to writing the injection parameters into the execution chip of the main controller, the execution chip determines the execution time of driving the cylinder to be injected according to the injection parameter, and drives the cylinder to work when the execution time is reached.

Method 2: When the control subject is the slave controller, the phase sensor is used to calculate the injection parameters of the cylinder to be injected, and the injection parameters are sent to the slave controller; the slave controller The specific principle of controlling the injection of the cylinder to be injected according to the injection parameter is as follows:

Enter the power-on state, and at the same time make the slave controller enter the power-on state, and start timing at the same time; that is, the master controller and the slave controller are simultaneously powered on and start timing at the same time.

After the master controller and the slave controller are both powered on, the phase interrupt signal is triggered in the master controller, so that the master controller calculates the injection parameters of the cylinder to be injected and the first delayed injection time through the phase sensor;

After the calculation is completed, the injection parameters, the first delayed injection time and the current master timing time of the master controller are sent to the slave controller through CAN communication;

When the slave controller receives the injection parameters, the first delayed injection time and the master timing time, the CAN communication is interrupted immediately, and the current slave timing time of the slave controller is recorded;

The slave controller calculates the second delayed injection time according to the master timing time, the slave timing time and the first delayed injection time;

The slave controller controls the cylinder to be injected to perform injection after waiting for the second delayed injection time according to the injection parameter.

Specifically, the data communication between the master controller and the slave controller includes but is not limited to CAN communication, which is only described in the form of an example in the embodiment of the present invention.

Further, the slave controller for calculating the second delayed injection time according to the master timing time, the slave timing time and the first delayed injection time is specifically used for:

Subtracting the master timing time from the timing time to obtain the third delayed injection time; the third delayed injection time is the data transmission time of CAN communication;

The second delayed injection time is obtained by subtracting the third delayed injection time from the first delayed injection time.

Further, the slave controller is also used to judge whether the data transmission time of the CAN communication is valid. If the data transmission time exceeds the preset time range, it is considered that the CAN communication is abnormal, and an alarm prompt is required for maintenance processing.

It can be seen from the above description that in the control system of the multi-cylinder engine, whether the main controller controls the cylinder to be injected for injection or the slave controller controls the cylinder to be injected for injection, the injection parameters are calculated by the main controller based on a phase sensor. , that is, both the master controller and the slave controller control the injection of the cylinder to be injected on the basis of the phase information calculated by the master controller and the phase sensor, which also solves the problem that the master controller and the slave controller in the prior art are When the injection phase is discriminated based on the respective phase sensors, there is a problem in that the phase angle discriminated by each of them is different.

In addition, compared with the control system in the prior art, the control system of the multi-cylinder engine reduces one phase sensor, the structure becomes simpler, and the production cost is also reduced.

Based on the control system for a multi-cylinder engine provided by the above-mentioned embodiment of the present invention, another embodiment of the present invention also provides a control method for a multi-cylinder engine, and the control method is applied to the main control system in the control system. The controller, referring to FIG. 2 , FIG. 2 is a schematic flowchart of a control method for a multi-cylinder engine provided by an embodiment of the present invention, and the control method includes:

S10: Determine the control subject of the cylinder to be injected in the multi-cylinder engine;

In this step, since the cylinders in the multi-cylinder engine can be controlled by the master controller or the slave controller, and the control principles of the two are different, it is necessary to determine the control subject of the cylinder to be injected before executing the program.

S11: when the control subject is the main controller, the main controller calculates the injection parameter of the cylinder to be injected through the phase sensor, and controls the cylinder to be injected to perform injection according to the injection parameter;

S12: When the control subject is the slave controller, the master controller calculates the injection parameters of the cylinder to be injected through the phase sensor, and sends the injection parameters to the slave controller to The slave controller controls the cylinder to be injected to perform injection according to the injection parameter.

Specifically, the injection parameters include but are not limited to the phase angle, fuel injection amount, power-on time, advance angle, and TDC (Top Dead Center) angle of the cylinder to be injected, as well as the engine's Parameters such as speed.

It can be known from steps S11 and S12 that no matter whether the control subject of the cylinder to be injected is the master controller or the slave controller, the injection parameters are calculated by the master controller and the phase sensor connected to it, and the phase angle information reference In the same way, it also solves the problem that in the prior art, the master controller and the slave controller discriminate the injection phase according to their respective phase sensors, and there will be differences in the phase angles of the respective discriminators.

Further, the control subject is the main controller. Referring to FIG. 3 , FIG. 3 is a schematic flowchart of the main controller controlling the cylinder to be injected provided by the embodiment of the present invention; that is, the specific steps of step S11 are as follows:

S111: the main controller enters a power-on state;

Specifically, power on the main controller to make it enter a working state;

S112: Trigger a phase interruption signal in the main controller, and the main controller calculates the injection parameter of the cylinder to be injected through the phase sensor;

S113: Write the injection parameter into the execution chip of the main controller, the execution chip determines the execution time of driving the cylinder to be injected according to the injection parameter, and drives the cylinder to be injected to work when the execution time is reached.

Further, when the control subject is the slave device, refer to FIG. 4 , which is a schematic flowchart of a master controller and a slave controller controlling a cylinder to be injected according to an embodiment of the present invention; that is, the specific details of step S12 Proceed as follows:

S121: Both the master controller and the slave controller enter the power-on state, and start timing at the same time;

Specifically, when the master controller enters the power-on state, the slave controller enters the power-on state at the same time, and starts timing at the same time;

S122: Trigger a phase interruption signal in the main controller, and the main controller calculates the injection parameter and the first delayed injection time of the cylinder to be injected through the phase sensor;

S123: The master controller sends the injection parameter, the first delayed injection time and the current master timing time of the master controller to the slave controller;

Specifically, the master controller sends the injection parameters, the first delayed injection time and the current master timing time of the master controller to the slave controller through CAN communication, including but not limited to.

S124: the slave controller records the current slave timing time of the slave controller when receiving the injection parameter, the first delayed injection time and the master timing time;

Specifically, when the slave controller receives the injection parameters, the first delayed injection time and the master timing time, the CAN communication is interrupted immediately, and the current slave timing time of the slave controller is recorded.

S125: the slave controller calculates the second delayed injection time according to the master timing time, the slave timing time and the first delayed injection time;

Specifically, the slave controller subtracts the master timing time from the slave timing time to obtain a third delayed injection time; the third delayed injection time is the data transmission time of CAN communication;

The second delayed injection time is obtained by subtracting the third delayed injection time from the first delayed injection time.

S126: The slave controller controls the cylinder to be injected to perform injection after waiting for the second delayed injection time according to the injection parameter.

It can be seen from the above description that in the control method of the multi-cylinder engine, whether the main controller controls the cylinder to be injected for injection or the slave controller controls the cylinder to be injected for injection, the injection parameters are calculated by the main controller based on a phase sensor. , that is, both the master controller and the slave controller control the injection of the cylinder to be injected on the basis of the phase information calculated by the master controller and the phase sensor, which also solves the problem that the master controller and the slave controller in the prior art are When the injection phase is discriminated based on the respective phase sensors, there is a problem in that the phase angle discriminated by each of them is different.

Further, referring to FIG. 5, FIG. 5 is another schematic flowchart of the master controller and the slave controller controlling the cylinder to be injected according to the embodiment of the present invention, and the control method further includes:

S127: the slave controller determines whether the second delayed injection time is less than a preset time;

S128: If yes, it is considered that the communication between the master controller and the slave controller is abnormal, and an alarm prompt message is sent.

If not, step S126 is executed.

Specifically, the slave controller also indirectly determines whether the data transmission time of CAN communication is valid. If the data transmission time exceeds the specified time range, it is considered that the CAN communication is abnormal, and an alarm prompt is required for maintenance processing.

In this embodiment, the control precision of the master controller and the slave controller in the coordinated control of the multi-cylinder engine is further improved.

The control method and system for a multi-cylinder engine provided by the present invention have been described in detail above. The principles and implementations of the present invention are described with specific examples in this paper. The method of the invention and its core idea; at the same time, for those skilled 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 content of this description should not be understood to limit the present invention.

It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. For the same and similar parts of the various embodiments, refer to each other Can. As for the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant part can be referred to the description of the method.

It should also be noted that in this document, relational terms such as first and second are used only to distinguish one entity or operation from another, and do not necessarily require or imply those entities or operations There is no such actual relationship or order between them. Furthermore, the terms "comprising", "comprising" or any other variation thereof are intended to encompass a non-exclusive inclusion such that a process, method, article, or device of a list of elements is included, inherent to, or is also included for, those processes. , method, article or device inherent elements. Without further limitation, an element qualified by the phrase "comprising a..." does not preclude the presence of additional identical elements in a process, method, article or apparatus that includes the element.

The above description of the disclosed embodiments enables any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. a kind of control system of multicylinder engine, which is characterized in that the control system include: master controller, from controller, Multicylinder engine with n cylinder and the phase detector being connect with the master controller；

The master controller, for judging the control main body of cylinder to be sprayed in the multicylinder engine；When the control main body is When the master controller, the nozzle parameter of the cylinder to be sprayed is calculated by the phase detector, and join according to the injection Number controls the cylinder to be sprayed and is sprayed；When the control main body be it is described from controller when, pass through the phase detector It calculates the nozzle parameter of the cylinder to be sprayed, and the nozzle parameter is sent to described from controller；

It is described from controller, sprayed for controlling the cylinder to be sprayed according to the nozzle parameter.

2. control system according to claim 1, which is characterized in that for by the phase detector calculate it is described to The nozzle parameter of ejection cylinder, and the master controller that the cylinder to be sprayed is sprayed is controlled according to the nozzle parameter, have Body is used for:

Into power-up state, and phase-triggered interrupt signal, to calculate the spray of the cylinder to be sprayed by the phase detector Penetrate parameter；The cylinder to be sprayed is controlled according to the nozzle parameter to be sprayed.

3. control system according to claim 1, which is characterized in that for by the phase detector calculate it is described to The nozzle parameter of ejection cylinder, and the nozzle parameter is sent to the master controller from controller, it is specifically used for:

Into power-up state, and make simultaneously it is described enter power-up state from controller, and start simultaneously at timing；

Phase-triggered interrupt signal, to calculate nozzle parameter and the first delay of the cylinder to be sprayed by the phase detector Injecting time；

After the completion of calculating, by the nozzle parameter, the analytic accounting of the first delay jet time and presently described master controller When the time be sent to it is described from controller；

For according to the nozzle parameter control the cylinder to be sprayed sprayed described in from controller, be specifically used for:

When receiving the nozzle parameter, the first delay jet time and the main timing time, record presently described From the slave timing time of controller；

According to the main timing time, described from timing time and the first delay jet time, the second delay jet is calculated Time；

According to the nozzle parameter, after waiting the second delay jet time, controls the cylinder to be sprayed and sprayed.

4. control system according to claim 3, which is characterized in that by according to the main timing time, described based on When time and the first delay jet time, calculate the described from controller of the second delay jet time, be specifically used for:

The main timing time is subtracted from timing time by described, obtains the third delay jet time；

The first delay jet time is subtracted into the third delay jet time, obtains the second delay jet time.

5. control system according to claim 1, which is characterized in that the nozzle parameter includes: the cylinder to be sprayed Phase angle, distributive value, power-up time, advance angle and TDC angle.

6. a kind of control method of multicylinder engine, which is characterized in that be applied to control as described in any one in claim 1-5 Master controller in system, the control method include:

Judge the control main body of cylinder to be sprayed in the multicylinder engine；

When the control main body is the master controller, joined by the injection that the phase detector calculates the cylinder to be sprayed Number, and control the cylinder to be sprayed according to the nozzle parameter and sprayed；

When the control main body be it is described from controller when, joined by the injection that the phase detector calculates the cylinder to be sprayed Number, and the nozzle parameter is sent to it is described from controller so that described control institute according to the nozzle parameter from controller Cylinder to be sprayed is stated to be sprayed.

7. control method according to claim 6, which is characterized in that it is described by the phase detector calculate it is described to The nozzle parameter of ejection cylinder, and control the cylinder to be sprayed according to the nozzle parameter and sprayed, comprising:

Into power-up state, and phase-triggered interrupt signal, to calculate the spray of the cylinder to be sprayed by the phase detector Penetrate parameter；

The cylinder to be sprayed is controlled according to the nozzle parameter to be sprayed.

8. control method according to claim 6, which is characterized in that it is described by the phase detector calculate it is described to The nozzle parameter of ejection cylinder, and the nozzle parameter is sent to it is described from controller so that it is described from controller according to described in Nozzle parameter controls the cylinder to be sprayed and is sprayed, comprising:

Into power-up state, and make simultaneously it is described enter power-up state from controller, and start simultaneously at timing；

Phase-triggered interrupt signal, to calculate nozzle parameter and the first delay of the cylinder to be sprayed by the phase detector Injecting time；

After the completion of calculating, by the nozzle parameter, the analytic accounting of the first delay jet time and presently described master controller When the time be sent to it is described from controller so that it is described from controller when receiving the nozzle parameter, the first delay spray When penetrating time and the main timing time, record the presently described slave timing time from controller, also make it is described from controller according to According to the main timing time, it is described from timing time with the first delay jet time, calculate the second delay jet time, also From controller according to the nozzle parameter described in making, after waiting the second delay jet time, control described to be sprayed Cylinder is sprayed.

9. control method according to claim 8, which is characterized in that it is described also make it is described from controller according to the analytic accounting When time, described from timing time and the first delay jet time, calculated for the second delay jet time, comprising:

The main timing time is subtracted from timing time by described, obtains the third delay jet time；

The first delay jet time is subtracted into the third delay jet time, obtains the second delay jet time.

10. control method according to claim 6, which is characterized in that the nozzle parameter includes: the cylinder to be sprayed Phase angle, distributive value, power-up time, advance angle and TDC angle.