CN106080604B - A kind of manual-gear vehicle uphill starting control method based on electronic parking system - Google Patents

Abstract

The invention discloses a ramp start control method for a manual transmission car based on an electronic parking system. The control process is as follows: starting the electronic parking system, judging whether the vehicle state is ready to start; if so, calculating the vehicle resistance and vehicle power, According to the relationship between vehicle resistance and vehicle power, it is judged whether the electronic parking system meets the starting release conditions; if the electronic parking system meets the starting release conditions, the electronic parking system is gradually released, and the vehicle is detected during the release of the electronic parking system The front and rear wheel speed pulses; according to the front and rear wheel speed pulses of the vehicle, it is judged whether to gradually release the electronic parking system until it is fully released or to maintain the current state of the electronic parking system and return to recalculate the vehicle resistance and vehicle power. The invention does not need additional components such as a clutch opening sensor, and can realize the ramp start of a manual transmission car through conventional signals and optimization algorithms, and the control process is simple and effective.

Description

A hill start control method for manual transmission vehicles based on electronic parking system

technical field

The invention belongs to the technical field of automobile control, and in particular relates to a method for controlling ramp start of a manual transmission automobile based on an electronic parking system.

Background technique

The parking brake of a traditional manual transmission car is generally completed by manual operation. When starting on a hill, the parking handle is manually operated to reduce the parking force to start the hill. The natural defect of this method is that it is unsafe when starting. And can't operate for the less powerful driver. The electronic parking system has been maturely used in automatic transmission vehicles. Although a small number of electronic parking systems are currently used in manual transmission vehicles, they are all controlled by adding clutch opening sensors (sensors that detect the degree of clutch engagement) and other components. , increasing the design difficulty, process and cost of the clutch components.

Contents of the invention

The object of the present invention is to provide a hill start control method for a manual transmission vehicle based on an electronic parking system in order to solve the above-mentioned deficiencies in the background technology.

The technical solution adopted by the present invention is: a method for controlling the hill start of a manual transmission car based on an electronic parking system, comprising the following steps:

Step 1, the vehicle is parked on the ramp road, the electronic parking system is activated, and it is judged whether the vehicle is in the ready-to-start state;

Step 2, if the vehicle state is not ready to start, return to step 1;

Step 3, if the vehicle state is ready to start, calculate the vehicle resistance and vehicle power, and judge whether the electronic parking system meets the start release condition according to the relationship between the vehicle resistance and the vehicle power;

Step 4, if the electronic parking system does not meet the start release condition, return to step 1;

Step 5: If the electronic parking system satisfies the starting release condition, start to gradually release the electronic parking system, and detect the front and rear wheel speed pulses of the vehicle at the same time during the release of the electronic parking system; according to the vehicle front and rear wheel speed The pulse judgment is to gradually release the electronic parking system until the electronic parking system is completely released or maintain the current state of the electronic parking system and return to step 3.

Further, the method for judging whether the vehicle state is the ready-to-start state is: detecting the engine speed and the accelerator pedal position, and when the detected engine speed is greater than the idle range and the accelerator pedal position is greater than 1%, it is judged that the vehicle state is the ready-to-start state, Otherwise, it is judged that the state of the vehicle is not the ready-to-start state.

Further, the calculation method of the vehicle resistance F _resistance is:

F _resistance = F _{sliding force} + F _{rolling resistance}

Among them: G is the gravity of the vehicle, X is the longitudinal acceleration; g is the acceleration of gravity; η is the rolling resistance coefficient.

Further, the calculation method of the vehicle power F _power is:

F _power = N*T*x*y/r, where N is the combined torque of output torque and rotational speed, T is the clutch efficiency, x is the transmission ratio, y is the main reduction ratio, and r is the wheel radius.

Further, the method for judging whether the electronic parking system satisfies the start release condition is: if the relationship between the vehicle resistance and the vehicle power satisfies F _power - F _resistance ≥ N _map , and N _map is a calibration data value, then judge the electronic parking system The system meets the starting release condition, otherwise it is judged that the electronic parking system does not meet the starting release condition.

Further, the conditions for judging the gradual release of the electronic parking system until it is fully released are: during the process of gradually releasing the electronic parking system, the detected front wheel speed pulses are ≥ m, the rear wheel speed pulses are ≤ n, and the front wheel speed pulses are ≤ n. The wheel speed pulses are offset in the same direction as the rear wheel speed pulses.

Further, the conditions for judging to keep the current release state of the electronic parking system and returning to step 3 are: during the process of releasing the electronic parking system, the detected front wheel speed pulse < m, and the rear wheel speed pulse ≤ n , and the offset direction of the front wheel speed pulse is the same as that of the rear wheel speed pulse.

Furthermore, in the step 5, during the release of the electronic parking system or after the electronic parking system is completely released, if the detected front wheel speed pulse and the rear wheel speed pulse are in the opposite direction, the electronic parking The car system starts up again, return to step 3.

In the present invention, the existing electronic parking system is applied to a manual transmission vehicle, without additional components such as a clutch opening sensor, and the ramp start of the manual transmission vehicle can be realized through conventional signals and control algorithms, and the control process is simple. Safe and effective. When the driver pulls up the electronic parking switch, the electronic parking system applies different parking forces according to the size of the slope, which not only effectively prolongs the service life of the electronic parking system, but also eliminates the possibility of parking due to differences in slopes. Slope accidents caused by insufficient vehicle power occurred.

Description of drawings

Fig. 1 is a functional block diagram of the electronic parking system of the present invention.

Fig. 2 is a control flow chart of the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments to facilitate a clear understanding of the present invention, but they do not limit the present invention.

As shown in Figure 1, it is a functional block diagram of the electronic parking system adopted in the present invention, including Hall linear sensor H, Hall pulse sensor I, longitudinal acceleration sensor J, single-chip microcomputer K, motor drive circuit L and other components, wherein Hall The Hall linear sensor H is used to detect the cable displacement of the electronic parking system, the Hall pulse sensor I is used to detect the motor speed, the longitudinal acceleration sensor J is used to detect the slope of the vehicle; the single chip microcomputer K is used to receive the vehicle through the CAN bus Basic signals, including receiving engine speed signal A, torque signal B, accelerator pedal position signal C, brake pedal switch signal D, vehicle speed signal E, wheel speed signal F, wheel speed pulse signal G and sending electronic parking system status signals; The motor drive circuit L is used to control the forward and reverse rotation of the motor M of the electronic parking system, and then control the parking or release of the electronic parking system.

As shown in FIG. 2, the method for controlling a hill start of a manual transmission vehicle based on the above-mentioned electronic parking system includes the following steps:

Step 1, the vehicle is parked on a sloped road (including horizontal roads, where the slope value of the horizontal road is 0), the electronic parking system is activated, and it is judged whether the state of the vehicle is ready to start.

The method for judging whether the vehicle state is ready to start is as follows: detect the engine speed and the position of the accelerator pedal. When the detected engine speed is greater than the idle range (such as 600 to 700 rpm) and the position of the accelerator pedal is greater than 1%, it is judged that the vehicle state is Ready to start state, otherwise it is judged that the vehicle state is not ready to start state.

Step 2, if the vehicle state is not ready to start, return to step 1;

Step 3, if the vehicle state is ready to start, and the detected vehicle speed is greater than or equal to 0 and less than X (X is the set value, such as 5), enter the start control state, start to calculate the vehicle resistance and vehicle power, according to the vehicle resistance and vehicle The size relationship of the power determines whether the electronic parking system meets the start release conditions. Satisfying the start release conditions means that the electronic parking system can ensure that the vehicle will not slip after the release.

The calculation method of vehicle resistance F _resistance is:

F _resistance = F _{sliding force} + F _{rolling resistance}

Where: G is the gravity of the vehicle, X is the longitudinal acceleration (m/s ² ); g is the gravity acceleration (9.8m/s ² ); η is the rolling resistance coefficient.

The calculation method of vehicle power F _power is: F _power =N*T*x*y/r, wherein, N is the combined torque of output torque and speed, T is the clutch efficiency, x is the transmission ratio, y is the main reduction ratio, r is the wheel radius.

If the above-mentioned relationship between vehicle resistance and vehicle power satisfies F _power - F _resistance ≥ N _map (N _map is a calibration data value, different values can be set according to the size of the slope), then it is judged that the electronic parking system meets the start release condition , otherwise it is judged that the electronic parking system does not meet the start release condition.

Step 4, if the electronic parking system judged above does not meet the start release condition, return to step 1;

Step 5: If the electronic parking system judged above meets the start release condition, start to release the electronic parking system gradually, and detect the front and rear wheel speed pulses of the vehicle at the same time during the release of the electronic parking system.

Step 6, in the process of gradually releasing the electronic parking system, when the detected front wheel speed pulse ≥ m and the rear wheel speed pulse ≤ n, and the offset direction of the front wheel speed pulse and the rear wheel speed pulse are the same At the same time, it shows that the vehicle has sufficient power, and the electronic parking system can be gradually released until the electronic parking system is fully released. When the electronic parking system is fully released (that is, the parking force is reduced to zero), the hill start is completed.

Step 7, in the process of gradually releasing the electronic parking system, when the detected front wheel speed pulse < m, the rear wheel speed pulse ≤ n, and the offset direction of the front wheel speed pulse and the rear wheel speed pulse are the same At the same time, it is explained that if the electronic parking system continues to be released, the vehicle may slip. At this time, it is necessary to maintain the current release state of the electronic parking system and return to step 3 to recalculate the vehicle power and vehicle resistance. Maintaining the current state of the release system of the electronic parking system means: if the above situation occurs when the electronic parking system is released partly, such as releasing one-third or one-half, the current state of the electronic parking system will maintain the release of three points. One or one half of the state, then return to step 3.

The m and n in the above step 6 and step 7 represent the calibration value of the number of pulses that the wheel rotates per second, which can be set according to actual needs, and m is greater than n.

In the above scheme, in order to further ensure the safety of the vehicle starting on a slope, if the following two situations occur, it indicates that the vehicle is slipping. At this time, the electronic parking system needs to be activated again to prevent the vehicle from slipping, and then return to step 3 to recalculate the vehicle power and After the vehicle resistance, judge whether the electronic parking system can be released: 1. In step 6, after the electronic parking system is completely released, if the detected front wheel speed pulse ≥ m, the rear wheel speed pulse ≥ n, and the front wheel The offset direction of the wheel speed pulse and the rear wheel speed pulse is opposite (it may be caused by releasing the accelerator when the vehicle speed has not reached a certain level); 2. In step 6 and step 7, the release process of the electronic parking system In this case, the offset direction of the front wheel speed pulse and the rear wheel speed pulse is opposite.

The above content is a further detailed description of the present invention in combination with specific embodiments, and it cannot be assumed that the specific implementation of the present invention is limited to these descriptions. For those of ordinary skill in the technical field to which the present invention belongs, some simple deduction or substitutions can be made without departing from the concept of the present invention, which should be deemed to belong to the protection scope of the present invention. The content not described in detail in this specification belongs to the prior art known to those skilled in the art.

Claims (7)

1. A method for controlling start of a manual gear car on a hill based on an electronic parking system, characterized in that it may further comprise the steps: Step 1, the vehicle is parked on the ramp road, the electronic parking system is activated, and it is judged whether the vehicle is in the ready-to-start state; Step 2, if the vehicle state is not ready to start, return to step 1; Step 3, if the vehicle state is ready to start, calculate the vehicle resistance and vehicle power, and judge whether the electronic parking system meets the start release condition according to the relationship between the vehicle resistance and the vehicle power; Step 4, if the electronic parking system does not meet the start release condition, return to step 1; Step 5: If the electronic parking system satisfies the starting release condition, start to gradually release the electronic parking system, and detect the front and rear wheel speed pulses of the vehicle at the same time during the release of the electronic parking system; according to the vehicle front and rear wheel speed The pulse judgment is to gradually release the electronic parking system until the electronic parking system is completely released or maintain the current release state of the electronic parking system and return to step 3; The conditions for judging the gradual release of the electronic parking system until it is completely released are: in the process of gradually releasing the electronic parking system, the detected front wheel speed pulse ≥ m, the rear wheel speed pulse ≤ n, and the front wheel speed The offset direction of the pulse and the rear wheel speed pulse is the same, m and n represent the calibration value of the number of pulses that the wheel rotates per second, and m is greater than n. 2. A hill start control method for a manual transmission car based on an electronic parking system according to claim 1, wherein the method for judging whether the vehicle state is ready to start is: detecting the engine speed and the accelerator pedal position, when the detected engine speed is greater than the idle range and the accelerator pedal position is greater than 1%, it is judged that the vehicle state is the ready-to-start state, otherwise it is judged that the vehicle state is not the ready-to-start state. 3. A method for controlling a car with manual transmission on a slope based on an electronic parking system according to claim 1, wherein the calculation method of the vehicle resistance F _resistance is: F _resistance = F _{sliding force} + F _{rolling resistance} Among them: G is the gravity of the vehicle, X is the longitudinal acceleration; g is the acceleration of gravity; η is the rolling resistance coefficient. 4. a kind of manual transmission car hill start control method based on electronic parking system according to claim 1, is characterized in that, the calculating method of described vehicle power F _power is: F _power = N*T*x*y/r, where N is the combined torque of output torque and rotational speed, T is the clutch efficiency, x is the transmission ratio, y is the main reduction ratio, and r is the wheel radius. 5. A method for controlling hill start of a manual transmission car based on an electronic parking system according to claim 1, wherein the method for judging whether the electronic parking system meets the starting release condition is: if the vehicle resistance and If the size relationship of vehicle power satisfies F _power - F _resistance ≥ N _map , and N _map is the calibration data value, it is judged that the electronic parking system meets the start release condition, otherwise it is judged that the electronic parking system does not meet the start release condition. 6. A method for controlling a hill start of a manual transmission vehicle based on an electronic parking system according to claim 1, wherein the conditions for determining to maintain the release state of the current electronic parking system and returning to step 3 are: In the process of releasing the electronic parking system, the detected front wheel speed pulse < m, the rear wheel speed pulse ≤ n, and the offset direction of the front wheel speed pulse and the rear wheel speed pulse is the same, m and n represent The calibration value of the number of pulses that the wheel rotates per second, m is greater than n. 7. A hill start control method based on an electronic parking system according to claim 1, characterized in that: in step 5, during the release of the electronic parking system or when the electronic parking system is completely After the release, if the detected front wheel speed pulse and the rear wheel speed pulse are offset in the opposite direction, the electronic parking system is activated again and returns to step 3.