A new control method for retarder control system

Abstract

The present invention belongs to the technical field of retarder cruise control, and in particular, relates to a novel retarder control system and control method. The control system includes a retarder, a retarder control unit, an ESC control unit and an ECU control unit, the retarder control unit is connected to the retarder, the ESC control unit is connected to the retarder control unit, and is used to collect the pressure value of the brake master cylinder for processing and transmitting it to the retarder control unit, the ECU control unit is connected to the retarder control unit, and is used to collect the brake signal and the throttle signal and transmit them to the retarder control unit, and the retarder control unit is used to adjust the retarder to the target working gear according to the brake signal, the throttle signal and the pressure value; the present invention is used to solve the problem that the driver frequently operates the handle and the vehicle is easily damaged.

Description

Technical Field

[0001] The invention belongs to the technical field of retarder cruise control, and in particular relates to a novel control method of a retarder control system. Background Art

[0002] Currently, vehicles operating in mountainous areas in Yunnan, Guizhou, Sichuan and other regions are subject to long downhill conditions. After long-term braking, the brakes of hydraulic brake vehicles will thermally decay, and the reduction of vehicle braking torque will seriously affect safety performance. Most vehicles will be equipped with eddy current retarders to compensate for and improve the problem of insufficient braking torque after brake thermal decay.

[0003] At present, the operation of the eddy current retarder is controlled by a combination of foot control and hand control. Since the manual control method requires the driver to frequently operate the handle to control the working gear, driving safety is affected, and this method cannot meet the vehicle's uniform downhill driving. At the same time, since the eddy current retarder will instantly generate a relatively large reverse drag torque when working, it is impossible to avoid the rear axle gear from being instantly impacted by the retarder's reverse drag torque before contact. Under this working condition, if the retarder is used for a long time, the surface of the rear axle gear teeth is prone to wear and the rear axle noise is loud or even the rear axle is damaged. Summary of the invention

[0004] The technical problem to be solved by the embodiments of the present application is to overcome the deficiencies of the prior art and provide a new retarder control system and control method that does not require the driver to frequently operate the handle and solves the problem of easy damage to the vehicle.

[0005] The technical solution for solving the above technical problems in the embodiment of the present application is as follows: A novel retarder control system, comprising: a retarder;

[0006] a retarder control unit, connected to the retarder;

[0007] An ESC control unit, connected to the retarder control unit, for collecting the pressure value of the brake master cylinder, processing it and transmitting it to the retarder control unit;

[0008] An ECU control unit, connected to the retarder control unit, for collecting brake signals and throttle signals and transmitting them to the retarder control unit;

[0009] The retarder control unit is used to adjust the retarder to a target working gear according to the brake signal, the throttle signal and the pressure value.

[0010] Compared with the prior art, the above technical solution has the following beneficial effects:

[0011] During vehicle driving, the retarder can be calibrated by the program to control its automatic opening or closing, and automatically identify the working gear without manual operation of the handle; the working gear of the retarder is determined by the master cylinder pressure value signal collected by the ESC control unit, and there is no need to install a pedal displacement sensor, a handle gear switch, or a separate pipeline pressure switch, etc., which reduces costs and failure rates; the gear division control is more flexible, and the multi-gear division can make the retarder output torque division more refined, the rear axle teeth are gradually in contact, the teeth are evenly stressed, and the instantaneous intervention of the retarder to generate a relatively large anti-drag torque is reduced, reducing wear and damage to the rear axle.

[0012] Furthermore, it also includes a cruise button connected to the retarder control unit, which is used to send a command to enter a cruise state to the retarder control unit.

[0013] Furthermore, it also includes: a wheel speed sensor connected to the ESC control unit, used to collect a current vehicle speed signal and transmit it to the ESC control unit;

[0014] A yaw angle sensor connected to the ESC control unit and used to collect a current acceleration signal and transmit it to the ESC control unit;

[0015] The ESC control unit is used to process and transmit to the retarder according to the vehicle speed signal and the acceleration signal;

[0016] The ECU control unit is used to process and transmit the brake signal and the throttle signal to the retarder control unit.

[0017] The vehicle speed signal and acceleration signal collected by the ESC control unit are used to determine the current vehicle speed. When the vehicle speed is less than 5Km / h, an exit-working-state instruction is sent; when the ABS or ESC function activation signal transmitted by the ESC control unit is identified, an exit-working-state instruction is issued; when the throttle opening percentage signal transmitted by the ECU control unit is identified to be greater than 0%, an exit-working-state instruction is issued.

[0018] Furthermore, it also includes a pressure sensor connected to the ESC control unit and used to collect the pressure value of the brake master cylinder;

[0019] When the pressure value is greater than 0 and less than a first threshold, the retarder control unit controls the retarder not to output torque.

[0020] When the pressure value of the brake master cylinder is greater than 0, the rear axle gears have gradually begun to contact. On the basis of the contact of the gears, the contact of the gears becomes closer and the force is evenly distributed as the pressure value increases. Before the pressure value reaches the first threshold, the retarder is controlled to be in a standby state without outputting braking torque, effectively solving the instantaneous impact of the retarder's anti-drag torque on the rear axle gears.

[0021] Furthermore, it also includes a CAN communication module, connecting the retarder control unit and the ESC control unit and the ECU control unit.

[0022] The present invention also provides a method for controlling a retarder, which comprises the following steps:

[0023] Get the switch signal of the cruise button;

[0024] Receive and store the current vehicle speed signal from the ESC control unit, and receive the acceleration signal from the yaw angle sensor in real time;

[0025] The input voltage of the retarder is adjusted according to the vehicle acceleration signal to keep the vehicle moving downhill at a constant speed.

[0026] Further, adjusting the input voltage of the retarder according to the vehicle acceleration signal includes:

[0027] According to the size of the vehicle acceleration signal, the braking torque that the retarder needs to adjust is calculated;

[0028] According to the braking torque that the retarder needs to adjust, the input voltage of the retarder is calculated and controlled.

[0029] Furthermore, according to the braking torque that the retarder needs to adjust, calculating and controlling the input voltage of the retarder includes:

[0030] Set the base voltage. The base voltage value is U 额 / n;

[0031] According to the braking torque that the retarder needs to adjust, input the base voltage of the target number;

[0032] Where n is the number of copies, U 额 is the rated voltage value.

[0033] Furthermore, the input voltage is calculated using the following formula:

[0034] ;

[0035] In the formula,

[0036] Output braking torque for the retarder;

[0037] is the torque constant;

[0038] is the magnetic flux;

[0039] is the input voltage;

[0040] is the coil resistance.

[0041] Furthermore, the retarder braking torque is calculated by the vehicle acceleration using the following formula:

[0042] ;

[0043] In the formula,

[0044] Output braking torque for the retarder;

[0045] is the main reducer transmission ratio;

[0046] Is the transmission efficiency of the main reducer;

[0047] is the total mass of the vehicle;

[0048] is the wheel rolling radius;

[0049] a is the vehicle acceleration.

[0050] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0051] 1. The pressure value of the brake master cylinder is detected by the ESC control unit, and then divided into multiple gears according to the size of the pressure value. When the pressure value is detected to be in this gear, the retarder control unit controls the retarder to output the corresponding torque, so as to directly control the torque output of the retarder by collecting the pressure value of the brake master cylinder, eliminating the manual control method of the handle gear switch and avoiding frequent operation of the handle gear switch.

[0052] 2. When it is detected that the brake master cylinder pressure is below the first threshold, the retarder is controlled not to output braking torque, that is, the retarder does not work at this time. However, the rear axle gears have gradually begun to contact. On the basis of the contact of the gears, as the pressure value increases, the contact of the gears becomes closer and the force is evenly distributed, which effectively solves the instantaneous impact of the retarder's anti-drag torque on the rear axle gears.

[0053] 3. The vehicle is controlled to enter the cruise state on the downhill by the cruise button. The braking torque that needs to be adjusted by the retarder is calculated according to the collected acceleration. Then the retarder input voltage is calculated according to the braking torque that needs to be adjusted to control the automatic matching control method of the braking torque of the retarder. That is, the corresponding braking torque is automatically matched according to the acceleration, the vehicle is kept at a constant speed downhill, and the safety hazards caused by long-term braking are avoided.

[0054] 4. Artificially divide the rated voltage into target portions, which can be divided according to the actual control accuracy. The input voltage corresponds to the cardinality voltage value of the corresponding portion according to the magnitude of the acceleration to match the output corresponding braking torque and control the vehicle to go downhill at a constant speed. By subdividing the rated voltage, the gears can be artificially divided more finely to make the control more precise. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0056] Figure 1 This is a schematic diagram of the structure of the first embodiment.

[0057] Figure 2 This is a schematic diagram of the process of Example 2. DETAILED DESCRIPTION

[0058] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0059] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0060] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "inside", "outside", etc., indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0061] In addition, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. In the description of the present invention, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0062] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0063] Example 1

[0064] like Figure 1 As shown, a novel retarder control system provided by an embodiment of the present invention includes: a retarder, a retarder control unit, an ESC control unit, and an ECU control unit;

[0065] The retarder control unit is connected to the retarder, and the retarder control unit is also connected to a main power switch and a battery in sequence, and the retarder control unit is also connected to a display for displaying current gear information in real time;

[0066] The ESC control unit is connected to the retarder control unit and is used to collect the pressure value of the brake master cylinder and transmit it to the retarder control unit;

[0067] The ECU control unit is connected to the retarder control unit and is used to collect brake signals and throttle signals and transmit them to the retarder control unit;

[0068] Wherein, it also includes a CAN communication module, which is connected to the retarder control unit, the ESC control unit and the ECU control unit;

[0069] The retarder control unit is used to adjust the retarder to a target working gear according to the brake signal and the pressure value. Specifically, when the ECU control unit detects that the brake signal is turned on, the retarder control unit automatically determines to enter the working mode. The retarder control unit determines that the retarder is opened to the target gear according to the pressure value of the brake master cylinder collected by the ESC control unit.

[0070] Specifically, it also includes a pressure sensor connected to the ESC control unit, and used to collect the pressure value of the brake master cylinder. When the pressure value is greater than 0 and less than a first threshold, the retarder control unit controls the retarder not to output torque;

[0071] When the pressure value is greater than the first threshold, the retarder control unit controls the retarder to start working and open to the target gear position.

[0072] The first threshold value may be set to 1 bar, that is, when the master cylinder pressure value is greater than or equal to 1 bar, the retarder starts to work.

[0073] Specifically, when 1bar≤master cylinder pressure value<3bar, the retarder starts working in the first gear (the retarder input voltage is 1 / 4U 额 , retarder output torque is about 100N.m);

[0074] When the main cylinder pressure is 3 bar ≤ 5 bar, the retarder starts working in the second gear (the input voltage of the retarder is 1 / 2U 额 , retarder output torque is about 200N.m);

[0075] When the master cylinder pressure is 5 bar ≤ 7 bar, the retarder starts working in the third gear (the retarder input voltage is 3 / 4U 额 , retarder output torque is about 300N.m);

[0076] When 7bar≤the master cylinder pressure value, the retarder starts to work in the fourth gear (the retarder input voltage is U 额 , retarder output torque is about 400N.m);

[0077] The specific gears can be divided into different intervals and gears according to actual conditions.

[0078] When the pressure value of the brake master cylinder is greater than 0, the rear axle gears have gradually begun to contact. On the basis of the contact of the gears, the contact of the gears becomes closer and the force is evenly distributed as the pressure value increases. Before the pressure value reaches the first threshold, the retarder is controlled to be in a standby state without outputting braking torque, effectively solving the instantaneous impact of the retarder's anti-drag torque on the rear axle gears.

[0079] During vehicle driving, the retarder can be calibrated by the program to control its automatic opening or closing, and automatically identify the working gear without manual operation of the handle; the working gear of the retarder is determined by the master cylinder pressure value signal collected by the ESC control unit, and there is no need to install a pedal displacement sensor, a handle gear switch, or a separate pipeline pressure switch, etc., which reduces costs and failure rates; the gear division control is more flexible, and the division of multiple gears can make the retarder output torque division more refined, the rear axle teeth are gradually in contact, the teeth are evenly stressed, and the instantaneous intervention of the retarder to generate a relatively large anti-drag torque is reduced, reducing wear and damage to the rear axle.

[0080] In this embodiment, a cruise button is also included, which is connected to the retarder control unit and is used to send a command to enter a cruise state to the retarder control unit. After receiving the command, the retarder control unit adjusts the input voltage to the retarder, thereby allowing the vehicle to maintain a constant speed downhill.

[0081] Specifically, it also includes: a wheel speed sensor and a yaw angle sensor, the wheel speed sensor is connected to the ESC control unit, and is used to collect the current vehicle speed signal and transmit it to the ESC control unit;

[0082] The yaw angle sensor is connected to the ESC control unit and is used to collect the current acceleration signal;

[0083] The ESC control unit transmits the vehicle speed signal and the acceleration signal to the retarder control unit, and the ESC control unit transmits the ABS or ESC function activation signal to the retarder control unit. When the vehicle speed is less than 5Km / h, an exit working state instruction is sent; when the ABS or ESC function activation signal transmitted by the ESC control unit is identified, an exit working state instruction is issued.

[0084] The ECU control unit is used to process and transmit the brake signal and the throttle signal to the retarder control unit. When it is recognized that the throttle signal transmitted by the ECU control unit is on, it is determined that the vehicle is to accelerate at this time and an exit working state instruction is issued.

[0085] That is, the triggering conditions for the retarder to exit the working mode are: the vehicle speed is less than 5Km / h; the ESC control unit sends an ABS or ESC function activation signal; the throttle opening percentage signal is greater than 0%; if any of the above three conditions is met, the retarder will be immediately controlled to exit the working mode, realizing automatic control of the retarder, saving time and effort in operation.

[0086] Example 2

[0087] like Figure 2 As shown, based on Example 1, this embodiment provides a control method for a retarder, which includes the following steps:

[0088] S1, obtain the switch signal of the cruise button;

[0089] S2, receiving and storing the current vehicle speed signal sent by the ESC control unit, and receiving the acceleration signal sent by the yaw angle sensor in real time;

[0090] Specifically, when the cruise button is pressed and the conditions for entering the cruise mode are met, the retarder control unit collects and records the vehicle speed signal from the ESC control unit at this time as the target vehicle speed. At the same time, it collects the acceleration signal from the yaw angle sensor as a judgment parameter for controlling the retarder braking torque output.

[0091] S3. Adjust the input voltage of the retarder according to the vehicle acceleration signal to keep the vehicle moving downhill at a constant speed.

[0092] Specifically, by reading the vehicle acceleration in real time, the input voltage of the retarder is controlled, and then the output braking torque of the retarder is controlled, so that the vehicle maintains Fdrive+Fweight=Fresistance+Fbraking, which satisfies the vehicle's continuous uniform downhill driving.

[0093] When the cruise button is pressed, the retarder control unit obtains the switch signal. If the vehicle is on an uphill slope and the driver steps on the accelerator normally, the retarder will stop working.

[0094] On flat ground, if you do not step on the accelerator or brake, the actual vehicle speed will be lower than the cruising speed when the cruise button is pressed. At this time, the retarder control unit will determine that the retarder does not need to work, and the input voltage is 0;

[0095] If you step on the brake, the retarder control unit obtains the master cylinder pressure and controls the retarder to continue working until the car stops, and then controls the retarder to stop working.

[0096] Specifically, adjusting the input voltage of the retarder according to the vehicle acceleration signal includes:

[0097] According to the size of the vehicle acceleration signal, the braking torque that the retarder needs to adjust is calculated;

[0098] According to the braking torque that the retarder needs to adjust, the input voltage of the retarder is calculated and controlled.

[0099] In order to maintain Fdrive + Fweight = Fresistance + Fbraking, that is, by controlling the input voltage of the retarder to control the braking torque of the retarder, the vehicle force balance is maintained to meet the vehicle's continuous uniform downhill driving requirements.

[0100] According to the braking torque that the retarder needs to adjust, adjusting the input voltage of the retarder includes:

[0101] Set the base voltage, the base voltage value is U 额 / n, where n is the number of copies, U 额 is the rated voltage value.

[0102] Specifically, the rated voltage is divided into n parts, each of which forms a smaller base voltage. The specific number of divided parts can be set manually according to control accuracy, etc.;

[0103] According to the braking torque that the retarder needs to adjust, input the base voltage of the target number;

[0104] After calculating the input voltage, the retarder control unit increases or decreases the input voltage of the retarder coil according to the multiple relationship of the set base voltage, thereby controlling the increase or decrease of the retarder braking torque, enabling the vehicle to travel downhill at the set cruising speed, accurately calculating the required braking torque through the change in deceleration, and forming the base voltage by finely dividing the rated voltage, so that each increase or decrease in the input voltage can maintain sufficient smoothness. Unlike the previous braking torque output being relatively limited and the vehicle speed fluctuation during downhill cruising being large, this control method makes downhill cruising easier to control and more precise.

[0105] In this embodiment, the input voltage is calculated using the following formula:

[0106] ;

[0107] In the formula,

[0108] Output braking torque for the retarder;

[0109] is the torque constant;

[0110] is the magnetic flux;

[0111] is the input voltage;

[0112] is the coil resistance.

[0113] The relationship between the braking torque and the input voltage is calculated through the above formula, and then the output braking torque of the retarder is controlled by controlling the input voltage to meet the requirements of uniform downhill cruising.

[0114] Furthermore, the retarder braking torque is calculated by the vehicle acceleration using the following formula:

[0115] ;

[0116] In the formula,

[0117] Output braking torque for the retarder;

[0118] is the main reducer transmission ratio;

[0119] Is the transmission efficiency of the main reducer;

[0120] is the total mass of the vehicle;

[0121] is the wheel rolling radius;

[0122] a is the vehicle acceleration.

[0123] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0124] 1. The pressure value of the brake master cylinder is detected by the ESC control unit, and then divided into multiple gears according to the size of the pressure value. When the pressure value is detected to be in this gear, the retarder control unit controls the retarder to output the corresponding torque, so as to directly control the torque output of the retarder by collecting the pressure value of the brake master cylinder, eliminating the manual control method of the handle gear switch and avoiding frequent operation of the handle gear switch.

[0125] 2. When it is detected that the brake master cylinder pressure is below the first threshold, the retarder is controlled not to output braking torque, that is, the retarder does not work at this time. However, the rear axle gears have gradually begun to contact. On the basis of the contact of the gears, as the pressure value increases, the contact of the gears becomes closer and the force is evenly distributed, which effectively solves the instantaneous impact of the retarder's anti-drag torque on the rear axle gears.

[0126] 3. The vehicle can be controlled to enter the cruise state on the downhill by the cruise button. The braking torque required by the retarder is calculated according to the collected acceleration, and then the braking torque of the retarder is automatically matched according to the corresponding matching input voltage. That is, the corresponding braking torque is automatically matched according to the acceleration, so that the vehicle can be kept at a constant speed downhill, avoiding the safety hazards of long-term braking.

[0127] 4. Artificially divide the rated voltage into target portions, which can be divided according to the actual control accuracy. The input voltage corresponds to the cardinality voltage value of the corresponding portion according to the magnitude of the acceleration to match the output corresponding braking torque and control the vehicle to go downhill at a constant speed. By subdividing the rated voltage, the gears can be artificially divided more finely to make the control more precise.

[0128] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A novel control method for a retarder control system, characterized in that: The control system comprises: a retarder; a retarder control unit, connected to the retarder; An ESC control unit, connected to the retarder control unit, for collecting the pressure value of the brake master cylinder, processing it and transmitting it to the retarder control unit; An ECU control unit, connected to the retarder control unit, for collecting brake signals and throttle signals and transmitting them to the retarder control unit; The retarder control unit is used to adjust the retarder to a target working gear according to the brake signal, the throttle signal and the pressure value; The control method comprises the following steps: Get the switch signal of the cruise button; Receive and store the current vehicle speed signal from the ESC control unit, and receive the acceleration signal from the yaw angle sensor in real time; According to the magnitude of the vehicle acceleration signal, the braking torque that the retarder needs to adjust is calculated, and according to the magnitude of the braking torque that the retarder needs to adjust, the input voltage of the retarder is calculated and controlled to keep the vehicle moving downhill at a constant speed; Among them, the retarder braking torque is calculated by the vehicle acceleration, using the following formula: ； Calculate the input voltage using the following formula: ； In the formula, Output braking torque for the retarder; is the torque constant; is the magnetic flux; is the input voltage; is the coil resistance; is the main reducer transmission ratio; Is the transmission efficiency of the main reducer; is the total mass of the vehicle; is the wheel rolling radius; a is the vehicle acceleration.

2. The control method according to claim 1, characterized in that: It also includes a cruise button connected to the retarder control unit and used to send a command to enter a cruise state to the retarder control unit.

3. The control method according to claim 1, characterized in that: Also includes: A wheel speed sensor connected to the ESC control unit and used to collect a current vehicle speed signal and transmit it to the ESC control unit; A yaw angle sensor connected to the ESC control unit and used to collect a current acceleration signal and transmit it to the ESC control unit; The ESC control unit is used to process and transmit to the retarder control unit according to the vehicle speed signal and the acceleration signal; The ECU control unit is used to process and transmit the brake signal and the throttle signal to the retarder control unit.

4. The control method according to claim 1, characterized in that: It also includes a pressure sensor connected to the ESC control unit and used to collect the pressure value of the brake master cylinder; When the pressure value is greater than 0 and less than a first threshold, the retarder control unit controls the retarder not to output torque.

5. The control method according to claim 1, characterized in that: It also includes a CAN communication module, which connects the retarder control and the ESC control unit and the ECU control unit.

6. The control method according to claim 1, characterized in that: According to the braking torque of the retarder, the input voltage of the retarder is adjusted as follows: Set the base voltage, the base voltage value is Urated / n; According to the braking torque that the retarder needs to adjust, input the base voltage of the target number; Among them, n is the number of parts and U rating is the rated voltage value.

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