CN104670020B - A kind of automobile fixed speed cruise control method - Google Patents

Abstract

The invention relates to the field of cruise control of automobiles, in particular to a control method of cruise control of automobiles. Input the cruise button signal to the meter IC, and at the same time, the engine management system EMS of the vehicle sends the cruise state of the vehicle to the meter IC through the CAN bus, and the meter IC sends the engine management system EMS to the engine management system EMS through the CAN bus according to the cruise button signal and the cruise state received. The cruise request signal and the target vehicle speed signal are output, and the engine management system EMS implements the switching of the cruise state according to the received cruise request signal, target vehicle speed signal and vehicle state signal. The instrument IC participates in the control logic of the engine management system EMS to complete the cruise function, which reduces the burden on the engine management system EMS. The engine management system EMS realizes the switching of the cruise state according to the cruise request signal sent by the instrument IC, the target vehicle speed signal and the vehicle status signal sent by other modules of the vehicle, making the cruise control mode more reasonable and perfect.

Description

A method for controlling cruise control of a vehicle

technical field

The invention relates to the field of cruise control of automobiles, in particular to a control method of cruise control of automobiles.

Background technique

When the car is running, the driver controls the speed of the vehicle through the opening of the accelerator pedal. When the car is running on a relatively flat road, the speed does not need to change greatly, so the opening of the accelerator pedal also needs to be adjusted. Stabilized at the corresponding opening, the driver will feel tired if he steps on the accelerator pedal for a long time. The constant speed cruise function can help the driver set the driving speed of the car, reduce the driver's fatigue, and at the same time maintain the smoothness and stability of the engine torque output during driving, which is also very beneficial to reduce fuel consumption.

As consumers have higher and higher cost-effective requirements for car configurations, ordinary household passenger cars have also begun to be equipped with cruise control functions. At the same time, consumers are paying more and more attention to the rationality and comfort of the human-machine interface in addition to increasing their requirements for car functions. The control of the traditional cruise function takes place inside the engine management system EMS. The instrument IC does not participate in the control logic, but only serves as a display function. The human-machine interface is relatively simple. In addition, the switching function between various cruise states is not perfect. Therefore, it is very necessary to provide a reasonable vehicle constant speed cruise control method to facilitate the construction of a relatively complete man-machine interface.

Contents of the invention

The object of the present invention is to provide a method for controlling cruise control of an automobile. The instrument IC participates in the control and display of the cruise function, and the human-machine interface is more reasonable, and the switching of the cruise state according to the implementation status of the vehicle makes the cruise function more perfect and reasonable.

The technical solution of the present invention is: a method for controlling cruise control of an automobile, in which the cruise button signal is input to the meter IC, and at the same time, the engine management system EMS of the vehicle sends the cruise control state of the vehicle to the meter IC through the CAN bus, and the meter IC Output the cruise request signal and target vehicle speed signal to the engine management system EMS through the CAN bus according to the received cruise button signal and the cruise control state, and the described engine management system EMS performs cruise according to the received cruise request signal, target vehicle speed signal and vehicle status signal Control state switching.

Further, the meter IC controls the output of the cruise request signal and the target vehicle speed signal according to the received cruise button signal and the cruise control state in the following manner:

The cruise buttons include a Cruise key for turning on/off the cruise function, a Cancel key for exiting the cruise, a Set/- key for activating the cruise after the cruise function is turned on or slowing down during the cruise, and a key for the previous cruise. Resume/+ key for returning to the target speed and entering cruise or acceleration;

The cruise control state includes cruise failure state, cruise condition unsatisfied state, cruise preparation state, normal cruise state, overtaking cruise state and exit cruise state;

Press the Cruise button, regardless of the cruise control status of the vehicle, the cruise function is turned on or off at this time, and the cruise request signal and target vehicle speed signal output by the instrument IC to the engine management system EMS are invalid signals;

Press the Cancel key, the meter IC will output an invalid cruise request signal to the engine management system EMS, and the output target vehicle speed signal is an invalid target vehicle speed signal when it has not entered the cruise before, and it is the last cruise when it has entered the cruise before. Target speed signal;

When the vehicle is in the state of cruising failure or the cruising condition is not satisfied, press any key, and the instrument IC will output invalid cruise request signals and invalid target vehicle speed signals to the engine management system EMS;

When the vehicle is in the cruising preparation state, press the Set/- key, the cruise function is activated, and the instrument IC outputs a valid cruise request signal and a target speed signal equal to the current driving speed to the engine management system EMS; press the Resume/+ key, If the cruise has been entered before, the meter IC outputs a valid cruise request signal and the target vehicle speed signal of the last cruise to the engine management system EMS, and if the cruise has not been entered before, the meter IC outputs an invalid cruise request signal to the engine management system EMS and an invalid target speed signal;

When the vehicle is in the normal cruising state, press the Set/- key, the instrument IC will output a valid cruise request signal and target speed reduction signal to the engine management system EMS; press the Resume/+ key, the instrument IC will output to the engine management system EMS Valid cruise request signal and target vehicle speed increase signal;

When the vehicle is in overtaking cruise state, press the Set/- key, the meter IC will output a valid cruise request signal and a target speed signal equal to the current driving speed to the engine management system EMS; press the Resume/+ key, the meter IC will output to the EMS The engine management system EMS outputs a valid cruise request signal and a constant target vehicle speed signal.

Further, when the vehicle is in the normal cruising state, the rate of change and step size of the target vehicle speed signal decrease and increase change according to the time length of pressing the Set/- key and Resume/+ key.

Further, the meter IC displays and outputs the cruising state and the target vehicle speed, and at the same time warns the driver when the cruising state is in cruising failure, the cruising condition is not satisfied, or cruising and overtaking.

Further, after the vehicle is started, the initial cruise state of the vehicle is the cruise fault state. When the cruise-related signal diagnoses no faults, no safe operation of the brake or clutch, and the meter IC sends an invalid cruise request, the cruise state is changed from the cruise state to the cruise fault state. The fault state is switched to the cruise condition not satisfied state.

Further, when the vehicle is in a state where the cruising condition is not satisfied:

If the running state of the vehicle meets the cruise function activation calibration range, the vehicle will switch from the cruise condition unsatisfied state to the cruise ready state;

If the cruise-related signal diagnosis is faulty or there is a safe operation of stepping on the brake or clutch, the vehicle will switch from the cruise condition unsatisfied state to the cruise fault state.

Further, when the vehicle is in the cruise preparation state:

If the instrument IC sends a valid cruise request, the vehicle will switch from the cruise preparation state to the normal cruise state;

If the vehicle's operating state does not meet the cruise function activation calibration range, the vehicle will switch from the cruise preparation state to the cruise condition does not meet the state;

If the cruise-related signal diagnosis is faulty or there is a safe operation of stepping on the brake or clutch, the vehicle will switch from the cruise condition unsatisfied state to the cruise fault state.

Further, when the vehicle is in a normal cruising state:

If the driver steps on the accelerator pedal, when the difference between the driver's demand torque corresponding to the actual accelerator pedal and the cruise demand torque corresponding to the current cruise virtual accelerator reaches the calibration value, the vehicle will switch from the normal cruise state to the overtaking cruise state;

If the meter IC sends an invalid cruise request, the vehicle switches from the normal cruise state to the exit cruise state;

If the cruise-related signal diagnosis is faulty or there is a safe operation of stepping on the brake or clutch, the vehicle will switch from the normal cruise state to the cruise fault state.

Further, when the vehicle is in the overtaking cruise state:

If the driver releases the accelerator pedal, the speed of the vehicle will return to around the target speed under the action of resistance, and the vehicle will switch from the normal cruising state to the normal cruising state;

If the meter IC sends an invalid cruise request, the vehicle switches from the overtaking cruise state to the exit cruise state;

If the cruise-related signal diagnosis is faulty or there is a safe operation of stepping on the brake or clutch, the vehicle will switch from the overtaking cruise state to the cruise fault state.

Further, when the vehicle is in the exit cruise state:

If the demand torque corresponding to the virtual accelerator pedal is less than the demand torque corresponding to the actual accelerator pedal, the vehicle will switch from the exit cruise state to the cruise preparation state;

If the meter IC sends a valid cruising request, the vehicle will switch from the exit cruising state to the normal cruising state;

If the cruise-related signal diagnosis is faulty or there is a safe operation of stepping on the brake or clutch, the vehicle will switch from the exit cruise state to the cruise fault state.

The beneficial effects of the present invention are: the cruise control button is connected to the meter IC through a hard wire, the signal of the cruise control state is sent to the meter IC through the CAN bus, and the meter IC sends a cruise request signal to the engine management system EMS through the CAN bus And the target vehicle speed signal, participate in the control logic of the engine management system EMS to complete the cruise function, which reduces the control burden of the engine management system EMS. The engine management system EMS realizes the switching of the cruise state according to the cruise request signal sent by the instrument IC, the target vehicle speed signal and the vehicle status signal sent by other cruise-related modules of the vehicle, making the cruise control mode more reasonable and perfect. The instrument IC displays the target vehicle speed and cruising status, and the man-machine interface is more reasonable. When the cruising status is cruising failure and overtaking cruise, it will warn the driver to ensure the safety of driving.

Description of drawings

Fig. 1 is the functional block diagram of instrument IC connection structure of the present invention;

Fig. 2 is the control schematic diagram of the engine management system EMS of the present invention;

Fig. 3 is a logic judgment principle diagram of the cruise control state switching of the present invention;

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. The specific embodiments described here are only used to explain the present invention, not to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not constitute a conflict with each other.

The cruise control module of the present invention is integrated in the engine management system EMS, and the cruise function is mainly realized by the key input of the driver, the instrument IC and the engine management system EMS. As shown in Fig. 1, the meter IC of the present invention is connected with the cruise control button through a hard wire, and connected with the engine management system EMS through the CAN bus. The instrument IC participates in the control logic of the engine management system EMS to complete the cruise function. It can not only output the cruise request signal and the target vehicle speed signal according to the input cruise button signal and the cruise control status signal sent by the engine management system EMS. It can also display the cruise state and target vehicle speed, and warn the driver when the cruise state is in cruise failure and overtaking cruise, reminding the driver to drive safely.

In the present invention, the cruise control buttons include Cruise (cruising on/off key) for controlling the input of the cruise opening/closing signal, Cancel (cruising exit key) for controlling the input of the cruise exit signal, and Set/-(setting for controlling the input of the setting/deceleration signal). key/deceleration key), Resume/+ (resume key/acceleration key) to control the resume/acceleration signal input. And the cruising state of the present invention includes cruising fault, cruising condition not satisfied, cruising preparation, normal cruising, overtaking cruising and exit cruising. The meter IC can output corresponding cruise request signals and target vehicle speed signals according to different input cruise button signals and cruise state signals. This embodiment lists a set of output modes, as shown in the following table:

No matter what cruise state the vehicle is in, pressing the Cruise button can control the cruise function to be turned on or off. That is, when the cruise function is not turned on, the cruise function is turned on, but the cruise function is not activated, so the instrument IC outputs an invalid cruise request signal and an invalid target vehicle speed signal (ie 255) to the engine management system EMS; If it is turned on, the cruise function will be turned off directly (if it is in the normal cruise or overtaking cruise state at this time, it will directly exit the cruise and turn off the cruise function).

Regardless of the cruising status of the vehicle, press the Cancel key to exit cruising, so the instrument IC outputs an invalid cruising request signal to the engine management system EMS. If it has not entered cruise before, it will output an invalid target vehicle speed signal, if it has entered cruise before, it will output the target vehicle speed signal of the last cruise, enter the cruise preparation state, and wait for the cruise function to be activated.

When the vehicle is in the state of cruising failure or the cruising condition is not satisfied, no matter which button is pressed, it is invalid. At this time, the instrument IC outputs an invalid cruise request signal and an invalid target vehicle speed signal to the engine management system EMS;

When the vehicle is in the cruise preparation state, press the Set/- key to activate the cruise function that has been turned on and enter the normal cruise state. At this time, the instrument IC outputs a valid cruise request signal to the engine management system EMS and is equal to the current driving state. The target vehicle speed signal of the vehicle speed. And press the Resume/+ key, if the cruise has not been entered before, the key is invalid, at this time, the instrument IC outputs an invalid cruise request signal and an invalid target vehicle speed signal to the engine management system EMS; if the cruise has been entered before, the The case is valid, at this time the meter IC outputs a valid cruise request signal and the target vehicle speed signal of the last cruise to the engine management system EMS.

When the vehicle is in the normal cruising state, press the Set/- key, the instrument IC will output a valid cruise request signal and target speed reduction signal to the engine management system EMS; press the Resume/+ key, the instrument IC will output to the engine management system EMS Active cruise request signal and target speed increase signal. The rate of decrease and increase of the target vehicle speed and the step size are determined according to the length of time the Set/- or Resume/+ key is pressed.

When the vehicle is in the overtaking cruise state, when the driver releases the accelerator pedal and wants to return to normal cruise, the Resume/+ key is invalid, that is, the instrument IC does not respond to the command when the Resume/+ key is pressed, and the IC sends a message to the engine management system at this time. The EMS outputs a valid cruise request signal and a target vehicle speed unchanged signal, that is, the vehicle speed will return to the normal cruising speed before the overtaking cruise and continue driving. At this time, when the Set/- key is pressed, the meter IC outputs a valid cruise request signal and a target vehicle speed signal equal to the current driving speed to the engine management system EMS. That is, the vehicle will enter the normal cruising state with the current vehicle speed when the Set/- button is released as the target speed.

As shown in Figure 2, the vehicle status signals received by the engine management system EMS and sent by other cruise-related modules of the vehicle are: the actual vehicle speed signal sent by the ESC (body stability control system), and the gear speed signal sent by the TCU (automatic transmission control unit). Position signal, EPB (Electronic Parking Brake System) cruise exit signal for safety considerations, and some internal signals of EMS such as brake pedal, accelerator pedal, clutch pedal, engine operating conditions, current driver demand torque and cruise Related signal valid flags, etc. After receiving these relevant signals and the cruise request and target vehicle speed signal sent by the meter IC, the engine management system EMS compares the actual vehicle speed with the target vehicle speed requested by the cruise button, and calculates the driver's demand torque through the PID control method, thereby adjusting Control the size of the virtual accelerator pedal, the throttle of the engine is actuated according to the virtual accelerator pedal in the engine management system EMS, control and adjust the effective torque output of the engine, so that the vehicle can run according to the cruising target speed, and thus release the driver's feet Actual gas pedal. At the same time, in the process of completing the cruise function, various cruise states are output to the IC through the CAN bus.

The engine management system EMS will also make logical judgments based on the received signals to control the switching of the cruise state, as shown in Figure 3:

After the engine is started, the cruise control state will stay in the cruise fault state (EMS_CruiseCtrlSts=0), when the cruise-related signals (vehicle speed, clutch, brake pedal, accelerator pedal, cruise button, etc.) are diagnosed as faultless (Rvv_OBD==1), there is no Step on the brake or clutch and other safety operations (Securite_Ope!=1), when the cruise button request sent by the instrument is invalid (Rvv_Switch!=1), the cruise control state is switched to the cruise condition dissatisfied state (EMS_CruiseCtrlSts=1) (the cruise condition The unsatisfactory state refers to the vehicle running state such as the vehicle speed gear does not meet the cruise function activation calibration range); in the cruise condition does not meet the state, when the vehicle running state such as the vehicle speed gear, etc., meets the cruise function activation calibration range (Rvv_Veh_Conditon==1) , will enter the cruise preparation state (EMS_CruiseCtrlSts=2) (the cruise preparation state refers to the vehicle operating state such as the vehicle speed gear meets the cruise function activation calibration range), and waits for the cruise button to request an effective command (that is, press the Set/- button) Activate to enter the cruise; similarly, in the cruise preparation state or in the cruise process, the vehicle running state does not meet the cruise function setting range (Rvv_Veh_Conditon!=1), it will return to the cruise condition does not meet the state; the cruise button request is valid (Rvv_Switch ==1) (i.e. press the Set/- key), enter the normal cruise state (EMS_CruiseCtrlSts=3) (the vehicle cruises at the target speed); in the normal cruise process, if the driver steps on the accelerator pedal, when the actual accelerator When the driver's demand torque corresponding to the pedal is greater than the cruise demand torque corresponding to the current cruise virtual accelerator to a certain extent, that is, Torque_Req>=Torque_Rvv+Torque_delta1, the engine will respond to the driver's demand torque corresponding to the actual accelerator pedal, the vehicle accelerates, and the cruise enters the overtaking cruise state (EMS_CruiseCtrlSts=4); after the driver releases the accelerator pedal (Torque_Drive<=Torque_Rvv+Torque_delta2), the speed of the vehicle will slowly drop to about the target cruise (Actual_spd<=Target_spd+delta_spd) under the effect of resistance, and will re-enter the normal cruise state ( At this time, if the Set/- button is pressed, the vehicle will enter the normal cruising state with the current speed of the vehicle when the Set/- button is released as the target speed); in the cruising state of normal cruising or overtaking cruising, the driver presses the button Exit cruise, that is, the cruise button request is invalid (Rvv_Switch!=1), then enter exit cruise (EMS_CruiseCtrlSts=5); when the required torque corresponding to the virtual accelerator pedal falls and transitions below the required torque corresponding to the actual accelerator pedal, the vehicle re-enters Cruise readiness (E MS_CruiseCtrlSts=2), the vehicle will respond to the actual accelerator pedal again. Wherein, no matter which cruise state the vehicle is in, when any cruise-related signal diagnosis fails (Rvv_OBD!=1) or the security operation is activated (Securite_Ope==1), the cruise state will switch to the cruise failure state.

The above is only a specific embodiment of the present invention. It should be pointed out that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention shall be covered by the protection scope of the present invention. within.

Claims (9)

1. A method for controlling the constant speed cruise of an automobile, characterized in that: the cruise button is pressed to send the cruise button signal to the instrument IC through a hard line, and the engine management system EMS of the vehicle sends the cruise control state of the vehicle to the IC through the CAN bus The meter IC, the meter IC outputs a cruise request signal and a target vehicle speed signal to the engine management system EMS through the CAN bus according to the received cruise button signal and the cruise control state, and the cruise control state includes a cruise fault state and a cruise condition dissatisfied state , cruising preparation state, normal cruising state, overtaking cruising state and exit cruising state, the engine management system EMS implements the switching of the cruise control state according to the received cruising request signal, target vehicle speed signal and vehicle state signal, wherein, after the vehicle starts , the initial cruise state of the vehicle is the cruise fault state, when there is no fault in the diagnosis of the cruise-related signal, there is no safe operation of the brake or clutch, and the instrument IC sends an invalid cruise request, the cruise control state is switched from the cruise fault state to the cruise condition is not Satisfied state. 2. A kind of automobile constant speed cruising control method as claimed in claim 1, is characterized in that: the control mode that described meter IC controls cruise request signal and target vehicle speed signal output according to the cruise button signal and cruise state that receive is as follows: The cruise buttons include a Cruise key for turning on/off the cruise function, a Cancel key for exiting the cruise, a Set/- key for activating the cruise after the cruise function is turned on or slowing down during the cruise, and a key for the previous cruise. Resume/+ key for returning to the target speed and entering cruise or acceleration; Press the Cruise button, regardless of the cruise control status of the vehicle, the cruise function is turned on or off at this time, and the cruise request signal and target vehicle speed signal output by the instrument IC to the engine management system EMS are invalid signals; Press the Cancel key, the meter IC will output an invalid cruise request signal to the engine management system EMS, and the output target vehicle speed signal is an invalid target vehicle speed signal when it has not entered the cruise before, and it is the last cruise when it has entered the cruise before. Target speed signal; When the vehicle is in the state of cruising failure or the cruising condition is not satisfied, press any key, and the instrument IC will output invalid cruise request signals and invalid target vehicle speed signals to the engine management system EMS; When the vehicle is in the cruising preparation state, press the Set/- key, the cruise function is activated, and the instrument IC outputs a valid cruise request signal and a target speed signal equal to the current driving speed to the engine management system EMS; press the Resume/+ key, If the cruise has been entered before, the meter IC outputs a valid cruise request signal and the target vehicle speed signal of the last cruise to the engine management system EMS, and if the cruise has not been entered before, the meter IC outputs an invalid cruise request signal to the engine management system EMS and an invalid target speed signal; When the vehicle is in the normal cruising state, press the Set/- key, the instrument IC will output a valid cruise request signal and target speed reduction signal to the engine management system EMS; press the Resume/+ key, the instrument IC will output to the engine management system EMS Valid cruise request signal and target vehicle speed increase signal; When the vehicle is in overtaking cruise state, press the Set/- key, the meter IC will output a valid cruise request signal and a target speed signal equal to the current driving speed to the engine management system EMS; press the Resume/+ key, the meter IC will output to the EMS The engine management system EMS outputs a valid cruise request signal and a constant target vehicle speed signal. 3. A kind of automobile cruise control method as claimed in claim 2, characterized in that: when the vehicle is in the normal cruising state, the rate of change and the step size of the target vehicle speed signal decrease and increase according to the Set/-key, Resume The duration of the /+ key varies. 4. A kind of automobile constant speed cruise control method as claimed in claim 2, is characterized in that: described meter IC carries out display output to cruise control state and target vehicle speed, is in cruise failure state, cruise condition simultaneously in cruise control state When it is not satisfied or in the state of cruising and overtaking, the driver will be warned. 5. A kind of automobile constant speed cruise control method as claimed in claim 2, is characterized in that, when vehicle is in the state that cruise condition does not satisfy: If the running state of the vehicle meets the cruise function activation calibration range, the vehicle will switch from the cruise condition unsatisfied state to the cruise ready state; If the cruise-related signal diagnosis is faulty or there is a safe operation of stepping on the brake or clutch, the vehicle will switch from the cruise condition unsatisfied state to the cruise fault state. 6. A kind of automobile fixed-speed cruise control method as claimed in claim 2, is characterized in that, when vehicle is in cruising preparation state: If the instrument IC sends a valid cruise request, the vehicle will switch from the cruise preparation state to the normal cruise state; If the vehicle's operating state does not meet the cruise function activation calibration range, the vehicle will switch from the cruise preparation state to the cruise condition does not meet the state; If the cruise-related signal diagnosis is faulty or there is a safe operation of stepping on the brake or clutch, the vehicle will switch from the cruise condition unsatisfied state to the cruise fault state. 7. A kind of automobile constant speed cruise control method as claimed in claim 2, is characterized in that, when vehicle is in normal cruise state: If the driver depresses the accelerator pedal, the vehicle will switch from the normal cruise state to the overtaking cruise state when the driver's demand torque corresponding to the actual accelerator pedal is greater than the cruise demand torque difference calibration value corresponding to the current cruise virtual accelerator; If the meter IC sends an invalid cruise request, the vehicle switches from the normal cruise state to the exit cruise state; If the cruise-related signal diagnosis is faulty or there is a safe operation of stepping on the brake or clutch, the vehicle will switch from the normal cruise state to the cruise fault state. 8. A kind of automobile constant speed cruise control method as claimed in claim 2, is characterized in that, when vehicle is in overtaking cruise state: If the driver releases the accelerator pedal, the vehicle switches from the overtaking cruise state to the normal cruise state; If the meter IC sends an invalid cruise request, the vehicle switches from the overtaking cruise state to the exit cruise state; If the cruise-related signal diagnosis is faulty or there is a safe operation of stepping on the brake or clutch, the vehicle will switch from the overtaking cruise state to the cruise fault state. 9. A kind of automobile constant speed cruise control method as claimed in claim 2, is characterized in that, when vehicle is in exit cruise state: If the demand torque corresponding to the virtual accelerator pedal is less than the demand torque corresponding to the actual accelerator pedal, the vehicle will switch from the exit cruise state to the cruise preparation state; If the meter IC sends a valid cruising request, the vehicle will switch from the exit cruising state to the normal cruising state; If the cruise-related signal diagnosis is faulty or there is a safe operation of stepping on the brake or clutch, the vehicle will switch from the exit cruise state to the cruise fault state.