CN113062978B

CN113062978B - Control system and control method for AT transmission limp-home function

Info

Publication number: CN113062978B
Application number: CN202110287666.XA
Authority: CN
Inventors: 杨帆; 严鉴铂; 刘义; 李环; 徐旭; 毕乾坤
Original assignee: Shaanxi Fast Gear Co Ltd
Current assignee: Shaanxi Fast Gear Co Ltd
Priority date: 2021-03-17
Filing date: 2021-03-17
Publication date: 2023-04-21
Anticipated expiration: 2041-03-17
Also published as: CN113062978A

Abstract

The invention discloses a control system and a control method for a limp-home function of an AT (automatic transmission), wherein the system comprises a limp-home controller which is respectively connected with a switch box, a relay box and an AT (automatic transmission) electromagnetic valve, so that the limp-home controller and the AT electromagnetic valve can be directly connected when the relay box is closed in a limp-home running mode, the limp-home controller controls the AT electromagnetic valve, and when the AT transmission fails in an electric control mode, the transmission enters the limp-home mode through a switch and safely returns to a destination. The scheme of the invention is simple and flexible, increases the redundancy control, does not influence the normal gear control of the transmission and does not influence the normal driving of the vehicle. The limp control of the system is controlled by the limp home controller of the transmission, gear control of the transmission is achieved, fault judgment is achieved, safety and reliability are achieved, and interactivity is high. The control method in the scheme has strong applicability, and has less requirements on the whole vehicle when in matching, and can be used for controlling different types of limp home.

Description

Control system and control method for AT transmission limp-home function

[ field of technology ]

The invention belongs to the technical field of transmission control, and particularly relates to a control system and a control method for an AT transmission limp-home function.

[ background Art ]

In the running process of the vehicle, because the road condition is complex and changeable, the load is large, the possibility of accidental vehicle faults exists, and if the accident happens in the normal running process, the personal and property safety should be considered first, and the problem to be solved is how to transport the vehicle to the repair site. For large-scale special vehicles, the road rescue vehicle is difficult to rescue, or the rescue vehicle can reach the vehicle only after a long time, if the fault vehicle has self-rescue capability, the vehicle is a very recommended solution from the safety angle or the cost angle.

The "limp home" mode enables the electronic control system of the vehicle to still perform its basic functions in the event of a failure, enabling the vehicle to travel at a minimum performance level to a nearby repair location.

AT present, a limp home scheme of an AT transmission in the domestic market mainly aims AT mechanical faults or hydraulic faults, but when a vehicle is damaged in a driving process of the AT transmission controller, the vehicle is difficult to normally drive, and no corresponding solution exists in the existing limp home mode.

[ invention ]

The invention aims to overcome the defects of the prior art, and provides a control system and a control method for an AT transmission limp function, so as to solve the problem that the whole vehicle is difficult to normally run when an AT transmission controller is damaged in the running process of the vehicle in the prior art.

In order to achieve the purpose, the invention is realized by adopting the following technical scheme:

a control system for the limp function of an AT transmission comprises a limp home controller, wherein the limp home controller is respectively connected with a switch box, a relay box, an engine controller and an AT transmission electromagnetic valve; the relay box is connected with an AT transmission electromagnetic valve, the AT transmission electromagnetic valve is connected with a transmission clutch, and the transmission clutch is connected with a transmission output shaft;

the limp home controller is connected with an AT transmission controller.

The invention further improves that:

preferably, the limp home controller is connected with an instrument.

Preferably, the instrument, the switch box, the limp home controller and the relay box are all arranged in the whole vehicle cab.

Preferably, the switch box is provided with a limp function activating switch, a neutral gear switch, a forward gear switch and a reverse gear switch.

Preferably, the AT transmission controller is connected with an AT transmission solenoid valve.

Preferably, the AT transmission controller is connected with a shift handle.

A control method of a control system based on any one of the above AT transmission limp-home functions, comprising the steps of:

step 1, the limp home controller detects whether an AT transmission controller works normally or not; if not, executing the step 2, otherwise, continuously detecting whether the AT transmission controller works normally by the limp home controller;

step 2, when a function activating switch of the switch box is turned on, the limp home controller sends information to the relay box, the relay box is attracted, and the AT transmission electromagnetic valve is powered by the limp home controller;

and 3, when a gear switch in the switch box is selected, the AT transmission electromagnetic valve enables different transmission clutches to work cooperatively according to gear information, and the vehicle runs according to the gear information.

Preferably, in step 1, the limp home controller sends a signal to the AT transmission controller AT regular time according to a set time; if the AT transmission controller returns a correct signal, the limp home controller judges that the AT transmission controller works normally; and if the AT transmission controller does not return a signal or returns an error signal, the limp home controller judges that the AT transmission controller does not work normally.

Preferably, in step 3, the AT transmission solenoid valve closes different transmission clutches through the cooperation of the respective oil passages, so that the whole vehicle operates in different gear positions.

Preferably, in step 3, the operation information of the transmission clutch is displayed by an instrument.

Compared with the prior art, the invention has the following beneficial effects:

the invention discloses a control system for a limp-home function of an AT (automatic Transmission), which comprises a limp-home controller, wherein the limp-home controller is respectively connected with a switch box, a relay box and an AT electromagnetic valve, so that the limp-home controller and the AT electromagnetic valve can be directly connected when the relay box is closed in a limp-home running mode, the limp-home controller controls the AT electromagnetic valve, and when the AT transmission fails in an electric control mode, the transmission enters the limp-home mode through a switch and safely returns to a destination. The scheme of the invention is simple and flexible, increases the redundancy control, does not influence the normal gear control of the transmission and does not influence the normal driving of the vehicle. The limp control of the system is controlled by the limp home controller of the transmission, gear control of the transmission is achieved, fault judgment is achieved, safety and reliability are achieved, and interactivity is high. The control method in the scheme has strong applicability, and has less requirements on the whole vehicle when in matching, and can be used for controlling different types of limp home.

Further, the limp home controller is connected with the instrument, and the instrument, the switch box, the relay box and other devices are arranged in the whole vehicle cab, so that the operation of a driver is facilitated.

Further, the switch box is provided with an activation switch and a three-gear state, so that a driver can select according to requirements.

Further, the AT transmission controller is connected with the AT transmission electromagnetic valve, so that the AT transmission can control the AT transmission electromagnetic valve in the normal running process of the automobile.

The invention also discloses a limp home control method of the AT transmission, wherein when the limp home controller detects that the AT transmission controller has a problem, the limp home controller is directly connected with the electromagnetic valve of the AT transmission through the attraction of the relay box, so as to control the electromagnetic valve of the AT transmission, and replace the damaged control function of the AT transmission. The method mainly depends on an electric control mode to realize the limp function, mechanical or hydraulic components are not required to be added, the implementation mode is simple and convenient, the cost is low, the limp gear can be defined by a user, and the method is a low-cost and configurable AT transmission limp home electric control method.

[ description of the drawings ]

Fig. 1: the structure of the invention is schematically shown;

fig. 2: the control logic flow chart is provided;

in the figure: 1 is an AT transmission, 2 is an AT transmission controller, 3 is an AT transmission electromagnetic valve, 4 is a limp home controller, 5 is a switch box, 6 is a relay box, 7 is a whole vehicle cab, 8 is an engine, 9 is an engine controller, 10 is a transmission output shaft, 11 is an instrument, 12 is a gear shifting handle, and 13 is a transmission clutch.

In the figure: the solid line represents the mechanical connection, one dotted line represents the signal connection, and the other dotted line represents the oil circuit control.

[ detailed description ] of the invention

The invention is described in further detail below with reference to the attached drawing figures:

in the description of the present invention, it should be noted that, directions or positional relationships indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., are based on directions or positional relationships shown in the drawings, are merely for convenience of description and simplification of description, and do not indicate or imply that the apparatus or element to be referred to must have a specific direction, be constructed and operated in the specific direction, and thus should not be construed as limiting the present invention; the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; furthermore, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixed or removable, for example; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

The invention discloses an AT limp home control system and a control method. The invention is suitable for realizing the limp home after the AT has an electric control fault, the vehicle must comprise an engine 8, an AT automatic transmission 1, an AT transmission controller 2, a limp home controller 4, a switch box 5, a relay box 6 and the like, the AT transmission controller 2 is a main control TCU, the limp home controller 4 is a secondary control TCU, and the structural schematic diagram is shown in figure 1.

Referring to fig. 1, the present invention discloses a control system for an AT transmission limp-home function, comprising an AT transmission 1, a whole vehicle cab 7 and an engine 8, the AT transmission 1 and the engine 8 being mechanically connected for controlling the operation of the engine 8. The AT transmission 1 is in signal connection with the engine 8, and the AT transmission 1 is in signal connection with the whole vehicle cab 7.

The AT transmission 1 comprises an AT transmission controller 2, an AT transmission electromagnetic valve 3 and an AT transmission clutch; a limp home controller 4, a switch box 5, a relay box 6, an instrument 11 and a gear shifting handle 12 are arranged in the whole vehicle cab 7; an engine controller 9 is provided in the engine 8. The power output of the AT transmission 1 is the transmission power that is transferred to other components of the chassis of the vehicle via the transmission output shaft 10.

The device has two connection modes, and corresponds to two driving states:

when the automobile normally runs, the AT transmission controller 2 is in signal connection with the engine controller 9, the AT transmission controller 2 is in signal connection with the AT transmission electromagnetic valve 3, the AT transmission controller 2 is in signal connection with the instrument 11, the AT transmission controller 2 is in signal connection with the gear shifting handle 12, and the AT transmission controller 2 is in signal connection with the limp home controller 4. The AT transmission 1 is internally provided with a transmission clutch 13, the AT transmission electromagnetic valve 3 is mechanically connected with the transmission clutch 13, the AT transmission controller 2 can control the transmission clutch 13 by controlling the AT transmission electromagnetic valve 3, a specific clutch can be closed, different transmission gears are combined, and different gears can enrich the use road conditions of the vehicle and meet various driving requirements of a driver. The automatic gear shifting can lighten the labor intensity of a driver, the AT transmission 1 replaces the driver to make judgment of lifting gears to a great extent, meanwhile, the driver is helped to switch different gears, the labor intensity is reduced, meanwhile, the automatic gear shifting device also has a help effect on the fuel consumption economy of the whole vehicle, because the fuel consumption factors are fully considered in the early matching of the AT transmission 1 and the engine 8, a great amount of work is done on the optimization of the gear shifting point of the AT transmission 1, and the AT transmission 1 has unique advantages in some special transportation vehicles.

When in the limp home state, the engine controller 9 is in signal connection with the limp home controller 4, the limp home controller 4 is in signal connection with the meter 11, the limp home controller 4 is in signal connection with the relay box 6, and the limp home controller 4 is in signal connection with the switch box 4; a relay box 6 and an AT transmission solenoid valve 3. When the limp home controller 4 is started, corresponding information is sent to the engine controller 9 through the CAN bus to indicate that the transmission is in a limp mode at the moment, meanwhile, a rotating speed and torque limiting instruction is sent to the engine controller 9, and the rotating speed and torque of the engine 8 are limited by the engine controller 9, so that the function of enabling the vehicle to return to a safe place at a lower speed is realized.

Further, in the limp home mechanism of the present invention, the limp home controller 4 is connected to the AT transmission controller 2 through signals, and the limp home controller 4 is connected to the switch box 5 and the relay box 6 through signals, and when the AT transmission controller 2 fails, the limp home controller 4 is connected to the AT transmission solenoid valve 3 and the engine controller 9 through signals. According to the limp home control method, after the limp home controller 4 receives the signal of abnormal operation of the AT transmission controller 2, the control of the AT transmission electromagnetic valve 3 is taken over, and the limp function is realized.

Further, in the limp home mechanism of the present invention, the AT transmission solenoid valve 3 is mechanically connected to the transmission, and when the AT transmission controller 2 is operating normally, the AT transmission solenoid valve 3 is controlled by the AT transmission controller 2, and when the AT transmission controller 2 fails, the AT transmission solenoid valve 3 is controlled by the limp home controller 4.

Still further, in the limp home mechanism of the present invention, the control current of the AT transmission solenoid valve 3 is from the AT transmission controller 2 or the limp home controller 4, after the AT transmission solenoid valve 3 is energized, the AT transmission 1 oil closes the transmission clutch 13 through different oil paths, and the combination of specific clutches can form power transmission, so as to drive the vehicle forward or backward. The AT transmission controller 2 is in signal connection with the transmission electromagnetic valve, the AT transmission controller 2 is in signal connection with the limp home controller 4, the AT transmission electromagnetic valve 3 can be controlled by the AT transmission controller 2 or the limp home controller 4 through switching selection, when the AT transmission controller 2 breaks down, the AT transmission controller is switched to work by the limp home controller 4, and the electromagnetic valve receives control current from the limp home controller 4 to realize the limp home function.

Furthermore, in the limp home mechanism of the present invention, there are 4 switches in the switch box 5, one of which is a limp function activating switch, and the other 3 controls the AT transmission 1 to be in a neutral state, a forward state and a reverse state respectively. That is, when the AT transmission controller 2 system fails, the limp home controller 4 may control the transmission solenoid valve so that the transmission is in three limp-home conditions.

The limp home mechanism in the invention uses the limp home controller 4 to provide backup, and when the AT transmission controller 2 fails, the vehicle can still run AT a low speed and return to a specific position for maintenance.

A control system and a control method for AT transmission limp home, see in particular the control logic diagram described in fig. 2, the control method comprising the steps of,

step 1, in the running process of the automobile, the limp home controller 4 transmits signals to the AT transmission controller 2 according to the set time; when the vehicle runs normally, the AT transmission electromagnetic valve 3 is controlled by the AT transmission controller 2, the AT transmission controller 2 is connected with the engine controller 9 and the instrument 11 through signals, the engine controller 9 normally controls the engine 8 to run normally, a driver operates the gear shifting handle 12 in the whole vehicle cab 7, when the vehicle moves from N gear to D gear, the vehicle can move forward after stepping on the accelerator, the AT transmission 1 calculates proper gear according to the opening degree of the accelerator and the rotating speed of the transmission output shaft 10, and the AT transmission controller 2 realizes the gear switching; the essence of realizing the gear switching is that the selection and switching of different transmission routes of the AT transmission 1 are realized by changing the control current of the electromagnetic valve 3 of the AT transmission and adjusting the combination of the transmission clutch 13; under the action of control current, the AT transmission electromagnetic valve 3 changes the size and direction of a hydraulic oil way to push the transmission clutches 13 to be combined or separated, and two different transmission clutches 13 are combined to combine a certain gear of the AT transmission 1. When operating normally, the AT transmission controller 2 and the limp home controller 4 operate simultaneously, AT which time the limp home controller 4 does not participate in the transmission control; the limp home controller 4 monitors the working state of the AT transmission controller 2 in real time through CAN communication; the AT transmission 1 is mechanically coupled to an engine 8, and power and torque of the engine 8 are transferred through the AT transmission 1 to other driveline components.

Step 2, the limp home controller 4 receives a normal signal returned by the AT transmission controller 2, and repeats the step 1 to continuously monitor the AT transmission controller 2; when the limp home control 4 does not receive the returned normal operation signal, executing the step 3; in the running process of the special transportation vehicle, if the AT transmission controller 2 is abnormal, the AT transmission electromagnetic valve 3 is not controlled, because the transmission clutch 13 is a normally open electromagnetic valve, the torque of the engine 8 cannot be transmitted through the AT transmission 1, the AT transmission 1 cannot realize the power transmission function, the vehicle cannot normally run, and the influence on the safety of the vehicle is very large; when the transmission fails in an electric control manner, the limp home controller 4 monitors that the working state of the AT transmission controller 2 is abnormal, and the limp function switch is in a closed state, so that the limp home function is started; the claudication controller 4 drives the relay box 6 to be attracted, and the AT transmission electromagnetic valve 3 is controlled by the claudication controller 4; depending on the switching state, the transmission 1 can enter a limp neutral gear, a limp forward gear, and a limp reverse gear; after the aim is reached, the activation button in the switch box 5 is closed, and the limp home controller 4 is powered off at the moment to stop working. When the AT transmission controller 2 fails, the AT transmission 1 is in an abnormal state, and AT the moment, the limp home controller 4 supplies power to the AT transmission electromagnetic valve 3, and the transmission clutch is combined to form a power transmission path, so that the limp function under a specific gear is realized.

Furthermore, a limp home controller 4, a switch box 5 and a relay box 6 are introduced into the system, all 3 components are placed inside a whole vehicle cab 7, the switch box 5 is clearly indicated, and the limp home controller is not strictly forbidden in special cases; the limp home controller 4 can replace the AT transmission controller 2 to realize the management and control of the AT transmission 1; the switch box 5 is used as a switch for starting the limp home function and can also control the AT transmission 1 to be in a specific limp gear; the relay box 6 switches the control current source of the AT transmission solenoid valve 3, i.e., the control signal is from the AT transmission controller 2 or the limp home controller 4, so that the control command can be transmitted to the AT transmission solenoid valve 3 to realize the function of pushing the transmission clutch 13.

More specifically, when the driver is in a limp home state, firstly, the limp function activation switch in the switch box 5 is pressed, and AT the moment, the limp home controller 4 takes over the AT transmission controller 2, so that the control of the AT transmission 1 is realized; the specific limp home controller 4 controls the relay box 6 to be attracted to complete the control command switching of the AT transmission solenoid valve 3, and thereafter, the AT transmission solenoid valve 3 is controlled by the limp home controller 4 irrespective of the AT transmission controller 2; the driver selects corresponding AT speed changer 1 gear according to driving requirements, 3 different AT speed changer 1 gears are designed, and the gear is respectively: neutral gear (N), forward gear (D1) and reverse gear (R), and the corresponding 3 switches are respectively: neutral gear (N gear) starting switch, forward gear (D1 gear) starting switch and reverse gear (R gear) starting switch, and a driver reasonably uses the 3 switches, so that the limp-home function of the vehicle after getting rid of poverty and driving back to a maintenance point can be realized. In N gear, the fifth clutch works; in the D1 gear, the first clutch and the fifth clutch work simultaneously, and in the R gear, the third clutch and the fifth clutch work simultaneously.

When in the D1 gear or the R gear, the limp home controller 4 sends a torque and a rotation speed limiting command to the engine controller 9 through the CAN bus, and the rotation speed and the torque of the engine 8 in different gears are limited by the engine controller 9.

Under the limp home state, parts such as an engine controller 9, an instrument 11 and the like are in signal connection with the limp home controller 4, the engine controller 9 transmits an accelerator opening degree signal to the limp home controller 4, the instrument 11 collects signals of the limp home controller 4, and information such as a gear position, an oil temperature and the like of the AT transmission 1 is displayed on the instrument 11, so that a driver can conveniently check the signals.

It is further possible to extend that when the AT transmission 1 is in a limp-home state, the limp-home controller 4 sends a limp-home state signal to the meter 11, and when displaying that the vehicle is in a limp-home state, the driver is reminded to drive carefully; when the AT transmission 1 is in a limp-home state, the limp-home controller 4 sends a limp-home state signal to the engine controller 9, limits the torque of the engine 8 AT the moment, protects the safety of the transmission system, and reaches the destination safely for overhauling the vehicle. The limp home controller 4 controls the AT transmission solenoid valve 3 such that the corresponding clutch is closed.

From the perspective of each device, the control method of the present invention involves the following main aspects:

at transmission controller 2: when the vehicle runs normally, the transmission electromagnetic valve 3 is controlled by the AT transmission controller 2, the AT transmission controller 2 is connected with an ECU (electronic control unit) of the engine and a whole vehicle instrument through signals, interaction with the engine in a gear shifting process is realized, functions such as gear information and transmission oil temperature are displayed on the instrument, when the AT transmission controller 2 fails and cannot work normally, the transmission electromagnetic valve 3 is also uncontrolled, AT the moment, a driver cannot realize a gear engaging function and an automatic gear lifting function, and the vehicle is trapped in a certain place;

2. limp home controller 4: when the vehicle normally runs, the limp home controller 4 is in a silent state and is connected with the AT transmission controller 2 through signals, and when the AT transmission controller 2 is detected to be abnormal, the limp home controller 4 enters a standby state, and after a driver turns on a limp mode switch, the limp home controller 4 is started to enter a working state;

3. relay box 6: the relay box 6 is in signal connection with the claudication controller 4, the control right of the AT transmission electromagnetic valve 3 is switched, the relay box is placed AT a proper position of a cab, and the claudication controller 4 controls the AT transmission electromagnetic valve 3 through controlling the relay box 6 so as to drive a corresponding clutch to be closed, so that power transmission of the transmission is realized;

4. switch box 5: there are 4 switches in the switch box 5, one of which is a limp function switch, and the other 3 are respectively controlling the speed changer to be in a certain limp gear, and are respectively forward 1 gear, neutral gear and reverse gear (here the function is flexible, can adjust limp gear according to user's requirement).

The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, alternatives, and improvements that fall within the spirit and scope of the invention.

Claims

1.A control method of a control system of an AT transmission limp function is characterized in that the control system based on the AT transmission limp function,

the automatic control device comprises a limp home controller (4), wherein the limp home controller (4) is respectively connected with a switch box (5), a relay box (6), an engine controller (9) and an AT transmission electromagnetic valve (3); the relay box (6) is connected with an AT transmission electromagnetic valve (3), the AT transmission electromagnetic valve (3) is connected with a transmission clutch (13), and the transmission clutch (13) is connected with a transmission output shaft (10);

the limp home controller (4) is connected with an AT transmission controller (2);

the limp home controller (4) is connected with an instrument (11);

the instrument (11), the switch box (5), the limp home controller (4) and the relay box (6) are arranged in the whole vehicle cab (7);

the engine controller (9) is arranged in the engine (8); when the vehicle is in a limp home state, the limp home controller (4) sends a rotating speed and torque limiting instruction to the engine controller (9), and the engine controller (9) limits the rotating speed and torque of the engine (8) to realize the function of returning the vehicle to a safe place at a lower speed;

the switch box (5) is provided with a limp function activating switch, a neutral gear switch, a forward gear switch and a reverse gear switch;

the AT transmission controller (2) is connected with an AT transmission electromagnetic valve (3);

the AT transmission controller (2) is connected with a gear shifting handle (12);

the control method comprises the following steps:

step 1, the limp home controller (4) detects whether the AT transmission controller (2) works normally or not; if not, executing the step 2, otherwise, continuously detecting whether the AT transmission controller (2) works normally by the limp home controller (4); the limp home controller (4) sends signals to the AT transmission controller (2) according to the set time timing; if the AT transmission controller (2) returns a correct signal, the limp home controller (4) judges that the AT transmission controller (2) works normally; if the AT transmission controller (2) does not return a signal or returns an error signal, the limp home controller (4) judges that the AT transmission controller (2) does not work normally;

step 2, when a limp-home function activating switch of the switch box (5) is turned on, the limp-home controller (4) sends information to the relay box (6), the relay box (6) is attracted, and the AT transmission electromagnetic valve (3) is powered by the limp-home controller (4);

step 3, when a gear switch in the switch box (5) is selected, the AT transmission electromagnetic valve (3) enables different transmission clutches (13) to work cooperatively according to gear information, and a vehicle runs according to the gear information; the AT transmission electromagnetic valve (3) is matched with the adjusting oil way to enable different transmission clutches (13) to be closed, so that the whole vehicle runs in different gears;

the operating information of the transmission clutch (13) is displayed by means of a meter (11).