Engine overspeed protection control system and method

Abstract

The present application relates to engine overspeed protection control system, including engine body, first engine brake, vehicle speed signal, second engine brake, engine speed sensor, flywheel, third engine brake, electronic control unit, brake pedal signal. The present application also relates to engine overspeed protection control method, including steps: detecting key signal; the key signal is power-off state, executing stop overspeed protection process; the key signal is power-on state, detecting whether there is driver intervention; if there is driver intervention, executing intervention overspeed protection process; if there is no driver intervention, executing no intervention overspeed protection process. The present application reduces the wear of main brake pad, saves brake pad; in the case of small throttle, prevents the engine speed from being too high, and damages engine parts; in the process of stopping, prevents abnormal oil entering in the engine cylinder, causes the engine speed to be too high abnormally, and appears the situation that the engine cannot stop.

Description

Technical Field

[0001] This invention relates to the field of engine control technology, and more specifically to an engine overspeed protection control system and method. Background Technology

[0002] For engine overspeed protection, existing technologies only consider the situation where engine speed exceeds the overspeed protection threshold and engine braking is initiated when the driver presses the brake pedal.

[0003] A typical prior art example is Chinese invention patent application CN202110602389.7, entitled "An Engine Overspeed Protection Control Method, Device, Storage Medium and System", which discloses the following technical solution:

[0004] Based on whether the actual engine speed exceeds a preset engine speed threshold, when the engine speed exceeds the protection threshold, it determines whether the brake pedal should be pressed. If the brake pedal is pressed, engine auxiliary braking is activated to reduce the engine speed. This invention only determines whether to activate engine auxiliary braking based on engine speed and brake pedal position, without considering whether the engine is off when the key is off or when the engine speed is too high while driving. If the vehicle is driving, vehicle speed must be considered; if the engine is off when the key is off, the key switch signal must be considered. Furthermore, it does not consider whether auxiliary braking is needed when the engine speed is too high and the brake pedal is not pressed.

[0005] In addition, another typical prior art is the Chinese invention patent application with application number CN202210408861.8, entitled "Engine Overspeed Protection Control Method", which discloses the following technical solution:

[0006] Based on whether the engine speed exceeds a certain threshold, if it does, the driver presses the brake pedal, and simultaneously checks the exhaust temperature threshold to determine whether to close the intake throttle valve and activate the in-cylinder brake. This invention only considers the intervention scenario where the engine speed exceeds a certain threshold and the driver presses the brake pedal; it lacks overspeed protection under keyless ignition shutdown conditions and protection in situations where the driver does not press the brake pedal.

[0007] The defects of existing technology are due to the following reasons:

[0008] Based on the analysis of existing technical solutions, only the situation where engine braking intervenes when the engine speed exceeds the overspeed protection threshold and the driver presses the brake pedal is considered. When the engine overspeed protection threshold is exceeded, it is determined whether the brake pedal should be pressed. If the brake pedal is pressed, engine auxiliary braking is automatically activated to reduce the engine speed. However, the conditions under which the engine may overspeed are not fully considered.

[0009] Therefore, the shortcomings of existing technologies can be summarized in the following two points:

[0010] 1. When the engine speed exceeds a certain threshold, and there is no driver intervention to press the brake pedal, and the accelerator pedal opening is less than a certain threshold, if the engine speed is too high and there is no engine braking intervention, the engine parts may be damaged due to the excessive engine speed.

[0011] 2. When the key is turned off, abnormal oil intake into the engine cylinder occurs, and the engine speed is detected to exceed the set threshold. If engine braking is not considered at this time, the engine will not be able to stop, which will lead to damage to engine parts. Summary of the Invention

[0012] To address the aforementioned problems, this invention provides an engine overspeed protection control system and method. Its purpose is to reduce the wear of the main brake pads and save brake pads; prevent the engine speed from being too high and damaging engine parts under low throttle conditions; and prevent abnormal oil intake into the engine cylinders during shutdown, which could lead to abnormally high engine speeds and prevent the engine from failing to shut down.

[0013] To solve the above problems, the technical solution provided by the present invention is as follows:

[0014] An engine overspeed protection control system includes an engine body, a first engine brake, a vehicle speed signal, a second engine brake, an engine speed sensor, a flywheel, a third engine brake, an electronic control unit, and a brake pedal signal; wherein:

[0015] The first engine brake is an in-cylinder brake, used to brake cylinders 1 to 3 of the engine body; the first engine brake is electrically coupled to the electronic control unit; the first engine brake executes engine braking on cylinders 1 to 3 of the engine body according to the control of the electronic control unit.

[0016] The second engine braking is an in-cylinder braking system used to brake cylinders 4 to 6 of the engine body; the second engine braking is electrically coupled to the electronic control unit; the second engine braking executes engine braking on cylinders 4 to 6 of the engine body according to the control of the electronic control unit.

[0017] The third engine braking is exhaust braking;

[0018] The engine speed sensor is used to collect engine speed signals; the engine speed sensor is electrically coupled to the electronic control unit and sends the engine speed signals to the electronic control unit;

[0019] The electronic control unit also receives the vehicle speed signal and the brake pedal signal.

[0020] An engine overspeed protection control method utilizing an engine overspeed protection control system specifically includes the following steps:

[0021] S100. Detect key signal; the key signal includes power-on state and power-off state;

[0022] S200. Perform the following operation based on the key signal:

[0023] If the key signal is in the power-off state, then the shutdown overspeed protection procedure is executed;

[0024] If the key signal is in the power-on state, then execute S300;

[0025] S300. Detect whether there is driver intervention at present;

[0026] S400. Based on the test results, perform the following operations:

[0027] If there is driver intervention, the passive overspeed protection procedure will be executed;

[0028] If there is no driver intervention at present, the active overspeed protection procedure will be executed.

[0029] Preferably, the passive overspeed protection process specifically includes the following steps:

[0030] Sa100. The electronic control unit acquires the engine speed signal, accelerator pedal signal, brake pedal signal, and key signal in real time;

[0031] Sa200. Based on the engine speed signal, the accelerator pedal signal, the brake pedal signal, and the key signal, the following operations are performed:

[0032] If the combination of the engine speed signal and the brake pedal signal satisfies the triggering condition of the first passive overspeed protection sub-process, then the first passive overspeed protection sub-process is started and executed.

[0033] If the combination of the engine speed signal and the accelerator pedal signal satisfies the triggering condition of the second passive overspeed protection sub-process, then the second passive overspeed protection sub-process is started and executed.

[0034] If the key signal is in the power-down state, the third passive overspeed protection sub-process is initiated and executed.

[0035] Preferably, the first passive overspeed protection sub-process specifically includes the following steps:

[0036] Saa100. The electronic control unit acquires the engine speed signal and the brake pedal signal in real time;

[0037] Based on the vehicle speed signal and ABS status, the following operations are performed:

[0038] If the vehicle speed signal is greater than 0 and the ABS status is inactive, then execute Saa200;

[0039] Saa200. Compare the engine speed signal with a manually preset first speed threshold; then, based on the comparison result, perform the following operations:

[0040] If the engine speed signal is higher than the first speed threshold, then execute Saa300;

[0041] If the engine speed signal is not higher than the first speed threshold, return and execute Saa100 again;

[0042] Saa300 detects the brake pedal signal; then, based on the detection result, performs the following operations:

[0043] If the brake pedal signal indicates that the driver has pressed the brake pedal, then execute Saa400;

[0044] If the brake pedal signal indicates that the driver has not pressed the brake pedal, then return and execute Saa100 again; Saa400. Count the duration of the states Saa200 to Saa300; then, based on the statistical results, perform the following operations:

[0045] If the state of Saa200 to Saa300 is maintained for a time exceeding the first time threshold preset by the user, the electronic control unit will issue an engine braking activation command to activate the engine braking; then Saa500 will be executed.

[0046] If the state duration of Saa200 to Saa300 does not exceed the first time threshold, then return and execute Saa400 again;

[0047] Saa500. The electronic control unit acquires the engine speed signal and the brake pedal signal in real time;

[0048] Saa600. Compare the engine speed signal with a manually preset second speed threshold; then, based on the comparison result, perform the following operations:

[0049] If the engine speed signal is higher than the second speed threshold, then execute Saa700;

[0050] If the engine speed signal is not higher than the second speed threshold, the engine braking will automatically disengage.

[0051] Saa700. Compare the brake pedal signal with a manually preset brake pedal opening threshold; then, based on the comparison result, perform the following operations:

[0052] If the brake pedal signal is higher than the brake pedal opening threshold, then the first engine braking, the second engine braking, and the third engine braking are executed.

[0053] If the brake pedal signal is not higher than the brake pedal opening threshold, then the auxiliary braking is turned off.

[0054] Preferably, the second passive overspeed protection sub-process specifically includes the following steps: Sab100. The electronic control unit acquires the engine speed signal and the accelerator pedal signal in real time;

[0055] Based on the ABS status, perform the following operations:

[0056] If the ABS state is inactive, then execute Sab200;

[0057] Sab200. Compare the engine speed signal with a manually preset third speed threshold; then, based on the comparison result, perform the following operations:

[0058] If the engine speed signal is higher than the third speed threshold, then execute Sab300;

[0059] If the engine speed signal is not higher than the third speed threshold, return and execute Sab100 again;

[0060] Sab300 compares the accelerator pedal signal with a manually preset first accelerator opening threshold; then, based on the comparison result, performs the following operations:

[0061] If the accelerator pedal signal is not higher than the first accelerator opening threshold, then execute Sab400;

[0062] If the accelerator pedal signal is higher than the first accelerator opening threshold, return and execute Sab100 again;

[0063] Sab400. Statistically determine the duration of states maintained by Sab200 to Sab300; then, based on the statistical results, perform the following operations:

[0064] If the state of Sab200 to Sab300 is maintained for a time exceeding the second time threshold preset by the user, the electronic control unit will issue an activation command for engine braking, activating the first engine brake, the second engine brake, and the third engine brake; then Sab500 will be executed.

[0065] If the state duration of Sab200 to Sab300 does not exceed the second time threshold, then return and execute Sab400 again;

[0066] Sab500. The electronic control unit acquires the engine speed signal and the accelerator pedal signal in real time.

[0067] Sab600. Compares the engine speed signal with a manually preset fourth speed threshold; then, based on the comparison result, performs the following operations:

[0068] If the engine speed signal is higher than the fourth speed threshold, then execute Sab700;

[0069] If the engine speed signal is not higher than the fourth speed threshold, then engine braking is automatically disengaged;

[0070] Sab700 compares the accelerator pedal signal with a manually preset second accelerator opening threshold; then, based on the comparison result, performs the following operations:

[0071] If the accelerator pedal signal is higher than the second accelerator opening threshold, engine braking is automatically disengaged; if the accelerator pedal signal is not higher than the second accelerator opening threshold, the first engine braking, the second engine braking, and the third engine braking are deactivated.

[0072] Preferably, the third passive overspeed protection sub-process specifically includes the following steps: (Entry condition: vehicle speed less than 5km / h)

[0073] Sac100. The vehicle speed signal performs the following operations:

[0074] If the vehicle speed signal is less than 5 km / h, then execute Sac200.

[0075] Sac200. During the power-off state of the key signal, the electronic control unit acquires the engine speed signal in real time; Sac300. The engine speed signal is compared with a manually preset fifth speed threshold; then, based on the comparison result, the following operations are performed:

[0076] If the engine speed signal is higher than the fifth speed threshold, then Sac400 is executed;

[0077] If the engine speed signal is not higher than the fifth speed threshold, then return and execute Sac200 again;

[0078] Sac400. Calculate the state maintenance time of Sac300. Based on the statistical results, perform the following operations:

[0079] If the Sac300 state is maintained for a longer period than the third time threshold preset by the user, the electronic control unit will issue an engine braking activation command to activate the engine braking; then Sac500 will be executed.

[0080] If the state duration of Sac300 does not exceed the third time threshold, then return and execute Sac400 again;

[0081] Sac500. The electronic control unit acquires the engine speed signal in real time;

[0082] Sac600 compares the engine speed signal with a manually preset sixth speed threshold; then, based on the comparison result, performs the following operations:

[0083] If the engine speed signal is higher than the sixth speed threshold, then the first engine braking, the second engine braking, and the third engine braking are executed; if the engine speed signal is not higher than the sixth speed threshold, then the engine braking is turned off, and the fault of failure to stop the engine normally is recorded.

[0084] Preferably, the active overspeed protection process specifically includes the following steps:

[0085] Sb100. The electronic control unit acquires the engine speed signal, the vehicle speed signal, the accelerator pedal signal, the brake pedal signal, the engine status, and the ABS status in real time;

[0086] Sb200. Based on the engine speed signal, vehicle speed signal, accelerator pedal signal, brake pedal signal, engine status, and ABS status, determine the current application condition; then, based on the determination result, perform the following operations:

[0087] If the current application condition is a combination of engine overspeed protection and main braking, then the active main braking combination sub-process is started and executed.

[0088] If the current application condition is to detect engine speed, then start and execute the active engine speed detection subprocess.

[0089] Preferably, the active main braking combined sub-process specifically includes the following steps:

[0090] Sba100. Based on the vehicle speed signal, the ABS status, and the engine status, the following operations are performed:

[0091] If the vehicle speed signal is greater than 0, the ABS status is not activated, and the engine status is deceleration fuel cut-off, then the engine speed signal is detected in real time.

[0092] If the vehicle speed signal is not greater than 0, or the ABS is active, or the engine is not in a deceleration fuel cut-off state, then the first engine braking, the second engine braking, and the third engine braking will not be executed.

[0093] Sba200. Compare the engine speed signal with the first speed threshold; then, based on the comparison result, perform the following operations:

[0094] If the engine speed signal is higher than the first speed threshold, and the brake pedal signal is greater than 0, and the duration exceeds the first time threshold, then the first engine braking, the second engine braking, and the third engine braking are executed; then Sba300 is executed.

[0095] If the engine speed signal is not higher than the first speed threshold, or the brake pedal signal is not greater than 0, or the duration does not exceed the first time threshold, then the first engine braking, the second engine braking, and the third engine braking are not performed.

[0096] Sba300. The electronic control unit acquires the engine speed signal in real time;

[0097] Sba400. Compares the engine speed signal with the second speed threshold; then, based on the comparison result, performs the following operations:

[0098] If the engine speed signal is less than the second speed threshold, then the first engine brake, the second engine brake, and the third engine brake are turned off.

[0099] If the engine speed signal is not less than the second speed threshold, then return and execute Sba300 again.

[0100] Preferably, the active engine speed detection subprocess specifically includes the following steps:

[0101] Sbb100. Based on the ABS status, perform the following operations:

[0102] If the ABS status is active, the auxiliary braking will not be activated;

[0103] If the ABS status is inactive, then execute Sbb200;

[0104] Sbb200. The electronic control unit acquires the engine speed signal and the accelerator pedal signal in real time;

[0105] Sbb300 performs the following operations based on the engine speed signal and the accelerator pedal signal:

[0106] If the engine speed signal is greater than the third speed threshold, and the accelerator pedal signal is less than the manually preset third accelerator opening threshold, and the duration exceeds the second time threshold, then the first engine braking, the second engine braking, and the third engine braking are executed; then Sbb400 is executed.

[0107] If the engine speed signal is not greater than the third speed threshold, or the accelerator pedal signal is not less than the third accelerator opening threshold, or the duration does not exceed the second time threshold, then the first engine braking, the second engine braking, and the third engine braking are not performed.

[0108] Sbb400. The electronic control unit acquires the engine speed signal in real time;

[0109] Sbb500 compares the engine speed signal with the third speed threshold; then, based on the comparison result, performs the following operations:

[0110] If the engine speed signal is less than the third speed threshold, then the first engine brake, the second engine brake, and the third engine brake are turned off.

[0111] If the engine speed signal is not less than the third speed threshold, then return and execute Sbb400 again.

[0112] Preferably, the shutdown overspeed protection process specifically includes the following steps:

[0113] Sc100. The electronic control unit acquires the key signal and the vehicle speed signal in real time; then, based on the key signal and the vehicle speed signal, it performs the following operations:

[0114] If the key signal is in the power-off state and the vehicle speed signal is less than a manually preset first vehicle speed threshold, then Sc200 is executed.

[0115] If the key signal is in the power-on state and the vehicle speed signal is not less than the first vehicle speed threshold, then return and execute Sc100 again;

[0116] Sc200. The electronic control unit acquires the engine speed signal in real time;

[0117] Sc300 performs the following operations based on the engine speed signal:

[0118] If the engine speed signal is greater than the fifth speed threshold, then the first engine braking, the second engine braking, and the third engine braking are executed.

[0119] If the engine speed signal is greater than the sixth speed threshold, and if the engine speed signal is less than the fifth speed threshold, then execute the first engine braking, the second engine braking, and the third engine braking; then execute Sc400.

[0120] Sc400. The electronic control unit acquires the engine speed signal in real time;

[0121] Sc500 performs the following operations based on the engine speed signal:

[0122] If the engine speed signal is greater than the sixth speed threshold, then return to and execute Sc400 again;

[0123] If the engine speed signal is less than the sixth speed threshold, then the first engine brake, the second engine brake, and the third engine brake are turned off; then the engine failure to stop normally is recorded.

[0124] Compared with the prior art, the present invention has the following advantages:

[0125] 1. Because the electronic control unit of this invention receives engine speed sensor signals and brake pedal signals in real time, when it detects that the engine speed is higher than a certain threshold and the driver presses the brake pedal, and this state exceeds the set time threshold, the electronic control unit issues an activation command for engine braking to reduce the engine speed; when the speed is lower than the set threshold, it automatically disengages engine braking, thereby reducing the wear of the main brake pads and saving brake pads.

[0126] 2. Because the electronic control unit of this invention receives the engine speed sensor signal in real time, when it detects that the engine speed is higher than a certain threshold and the throttle is lower than a certain threshold, and this state exceeds the set time threshold, the electronic control unit issues an engine braking activation command to activate engine braking to reduce the engine speed; when the speed is lower than the set threshold or the throttle is higher than a certain threshold, the engine braking is automatically disengaged; thus, under low throttle conditions, the engine speed is prevented from being too high and damaging engine parts, thus playing the role of overspeed protection.

[0127] 3. When the key is turned off, if the engine speed is detected to exceed the set speed threshold and the engine speed remains above the speed threshold for a certain period of time, the electronic control unit issues an engine braking activation command to reduce the engine speed to below the set speed threshold. At the same time, it records the failure to stop the engine normally after power-off. This prevents abnormal oil intake into the engine cylinder during the shutdown process, which could lead to abnormally high engine speed and engine failure to stop, thus providing overspeed protection. Attached Figure Description

[0128] Figure 1 This is a schematic diagram of the engine overspeed protection system according to a specific embodiment of the present invention;

[0129] Figure 2 This is a schematic diagram of the shutdown overspeed protection process in a specific embodiment of the present invention under shutdown conditions;

[0130] Figure 3 This is a schematic diagram of the engine overspeed protection control process in a specific embodiment of the present invention.

[0131] The components are: 1. Engine body, 2. First engine brake, 3. Vehicle speed signal, 4. Second engine brake, 5. Engine speed sensor, 6. Flywheel, and 7. Third engine brake. Detailed Implementation

[0132] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. After reading the present invention, any modifications of the present invention in various equivalent forms by those skilled in the art will fall within the scope defined by the appended claims.

[0133] like Figure 1 As shown, an engine overspeed protection control system includes an engine body 1, a first engine brake 2, a vehicle speed signal 3, a second engine brake 4, an engine speed sensor 5, a flywheel 6, a third engine brake 7, an electronic control unit, and a brake pedal signal; wherein:

[0134] The first engine brake 2 is an in-cylinder brake used to brake cylinders 1 to 3 of the engine body 1; the first engine brake 2 is electrically coupled to the electronic control unit; the first engine brake 2 performs engine braking on cylinders 1 to 3 of the engine body 1 according to the control of the electronic control unit.

[0135] The second engine brake 4 is an in-cylinder brake used to brake the engines of cylinders 4 to 6 of the engine body 1. The second engine brake 4 is electrically coupled to the electronic control unit. The second engine brake 4 performs engine braking on cylinders 4 to 6 of the engine body 1 according to the control of the electronic control unit.

[0136] The third engine brake 7 is the exhaust brake.

[0137] The engine speed sensor 5 is used to collect engine speed signals; the engine speed sensor 5 is electrically coupled to the electronic control unit and sends the engine speed signals to the electronic control unit.

[0138] The electronic control unit also receives vehicle speed signal 3 and brake pedal signal.

[0139] An engine overspeed protection control method utilizing an engine overspeed protection control system specifically includes the following steps:

[0140] S100. Detect key signal; key signal includes power-on state and power-off state.

[0141] S200. Perform the following operations based on the key signal:

[0142] If the key signal is in the power-off state, the shutdown overspeed protection procedure will be executed.

[0143] like Figure 2 As shown in this specific embodiment, the shutdown overspeed protection process specifically includes the following steps:

[0144] Sc100. The electronic control unit acquires the key signal and vehicle speed signal 3 in real time; then, based on the key signal and vehicle speed signal 3, it performs the following operations:

[0145] If the key signal is in the power-off state and the vehicle speed signal 3 is less than the first preset vehicle speed threshold, then Sc200 is executed.

[0146] If the key signal is powered on and the vehicle speed signal 3 is not less than the first vehicle speed threshold, then return and execute Sc100 again.

[0147] The Sc200 electronic control unit acquires engine speed signals in real time.

[0148] Sc300 performs the following operations based on the engine speed signal:

[0149] If the engine speed signal is greater than the fifth speed threshold, then execute the first engine braking 2, the second engine braking 4, and the third engine braking 7.

[0150] If the engine speed signal is greater than the sixth speed threshold, and if the engine speed signal is less than the fifth speed threshold, then execute the first engine braking 2, the second engine braking 4, and the third engine braking 7; then execute Sc400.

[0151] The Sc400 electronic control unit acquires engine speed signals in real time.

[0152] Sc500 performs the following operations based on the engine speed signal:

[0153] If the engine speed signal is greater than the sixth speed threshold, return to and execute Sc400 again.

[0154] If the engine speed signal is less than the sixth speed threshold, then the first engine brake 2, the second engine brake 4, and the third engine brake 7 are turned off; then the engine failure to stop normally is recorded.

[0155] It should be noted that the shutdown overspeed protection process is mainly for overspeed protection of the engine during the engine shutdown process. At the same time, it serves as a condition for judging the power-off of the whole vehicle to prevent abnormal oil intake into the engine cylinders during the power-off process, which could cause the engine to run at excessively high speeds and result in the inability to shut down the engine.

[0156] If the key signal is in the power-on state, then execute S300.

[0157] S300. Detect whether there is driver intervention at present.

[0158] S400. Based on the test results, perform the following operations:

[0159] If there is driver intervention, the passive overspeed protection procedure will be executed.

[0160] In this specific embodiment, the passive overspeed protection process includes the following steps:

[0161] The Sa100 electronic control unit acquires engine speed signals, accelerator pedal signals, brake pedal signals, and key signals in real time.

[0162] Sa200 performs the following operations based on engine speed signal, accelerator pedal signal, brake pedal signal, and key signal:

[0163] If the combination of the engine speed signal and the brake pedal signal satisfies the triggering conditions of the first passive overspeed protection sub-process, then the first passive overspeed protection sub-process is started and executed.

[0164] If the combination of the engine speed signal and the accelerator pedal signal satisfies the triggering conditions of the second passive overspeed protection sub-process, then the second passive overspeed protection sub-process is started and executed.

[0165] If the key signal is in the power-off state, the third passive overspeed protection sub-process is initiated and executed.

[0166] In this specific embodiment, the first passive overspeed protection sub-process specifically includes the following steps:

[0167] The Saa100 electronic control unit acquires engine speed and brake pedal signals in real time.

[0168] Based on the vehicle speed signal and ABS status, perform the following operations:

[0169] If the vehicle speed signal is greater than 0 and the ABS status is inactive, then execute Saa200;

[0170] Saa200 compares the engine speed signal with a manually preset first speed threshold; then, based on the comparison result, performs the following operations:

[0171] If the engine speed signal is higher than the first speed threshold, then execute Saa300.

[0172] If the engine speed signal is not higher than the first speed threshold, return and execute Saa100 again.

[0173] Saa300 detects the brake pedal signal; based on the detection results, the following operations are performed:

[0174] If the brake pedal signal indicates that the driver has pressed the brake pedal, then execute Saa400.

[0175] If the brake pedal signal indicates that the driver has not pressed the brake pedal, return and execute Saa100 again.

[0176] Saa400. Statistically determine the duration of states from Saa200 to Saa300; then, based on the statistical results, perform the following operations:

[0177] If the duration of state Saa200 to Saa300 exceeds the first preset time threshold, the electronic control unit will issue an activation command for engine braking to start the engine braking; then Saa500 will be executed.

[0178] If the state duration of Saa200 to Saa300 does not exceed the first time threshold, then return and execute Saa400 again.

[0179] It should be noted that the purpose of activating engine braking is to reduce engine speed, thereby reducing wear on the main brake pads and conserving brake pads.

[0180] The Saa500 electronic control unit acquires engine speed signals in real time.

[0181] Saa600 compares the engine speed signal with a manually preset second speed threshold; then, based on the comparison result, performs the following operations:

[0182] If the engine speed signal is higher than the second speed threshold, then execute Saa700;

[0183] If the engine speed signal is not higher than the second speed threshold, the engine braking will automatically disengage.

[0184] Saa700 compares the brake pedal signal with a manually preset brake pedal opening threshold; then, based on the comparison result, performs the following operations:

[0185] If the brake pedal signal is higher than the brake pedal opening threshold, then execute the first engine braking 2, the second engine braking 4, and the third engine braking 7.

[0186] If the brake pedal signal is not higher than the brake pedal opening threshold, then the auxiliary brake is turned off.

[0187] In this specific embodiment, the second passive overspeed protection sub-process specifically includes the following steps:

[0188] The Sab100 electronic control unit acquires engine speed and accelerator pedal signals in real time.

[0189] Based on the ABS status, perform the following operations:

[0190] If the ABS status is inactive, then execute Sab200.

[0191] Sab200 compares the engine speed signal with a manually preset third speed threshold; then, based on the comparison result, performs the following operations:

[0192] If the engine speed signal is higher than the third speed threshold, then execute Sab300.

[0193] If the engine speed signal is not higher than the third speed threshold, return and execute Sab100 again.

[0194] Sab300 compares the accelerator pedal signal with a manually preset first accelerator opening threshold; then, based on the comparison result, performs the following operations:

[0195] If the accelerator pedal signal is not higher than the first accelerator opening threshold, then execute Sab400.

[0196] If the accelerator pedal signal is higher than the first accelerator opening threshold, return and execute Sab100 again.

[0197] Sab400. Statistically determine the duration of states maintained by Sab200 to Sab300; then, based on the statistical results, perform the following operations:

[0198] If the state of Sab200 to Sab300 is maintained for a longer period than the second time threshold preset by the user, the electronic control unit will issue an activation command for engine braking, activating the first engine brake 2, the second engine brake 4, and the third engine brake 7; then Sab500 will be executed.

[0199] If the state duration of Sab200 to Sab300 does not exceed the second time threshold, then return and execute Sab400 again.

[0200] The Sab500 electronic control unit acquires engine speed and accelerator pedal signals in real time.

[0201] Sab600 compares the engine speed signal with a manually preset fourth speed threshold; then, based on the comparison result, performs the following operations:

[0202] If the engine speed signal is higher than the fourth speed threshold, then execute Sab700.

[0203] If the engine speed signal is not higher than the fourth speed threshold, the engine braking will automatically disengage.

[0204] Sab700 compares the accelerator pedal signal with a manually preset second accelerator opening threshold; then, based on the comparison result, performs the following operations:

[0205] If the accelerator pedal signal is higher than the second accelerator opening threshold, engine braking will automatically disengage.

[0206] If the accelerator pedal signal is not higher than the second accelerator opening threshold, then the first engine brake 2, the second engine brake 4, and the third engine brake 7 are deactivated.

[0207] In this specific embodiment, the third passive overspeed protection sub-process specifically includes the following steps:

[0208] The Sac100 vehicle speed signal performs the following operations:

[0209] If the vehicle speed signal is less than 5 km / h, then execute Sac200.

[0210] Sac200. When the key signal is in the power-off state, the electronic control unit acquires the engine speed signal in real time.

[0211] Sac300 compares the engine speed signal with a manually preset fifth speed threshold; then, based on the comparison result, performs the following operations:

[0212] If the engine speed signal is higher than the fifth speed threshold, then Sac400 is executed.

[0213] If the engine speed signal is not higher than the fifth speed threshold, return and execute Sac200 again.

[0214] Sac400. Calculate the state maintenance time of Sac300. Based on the statistical results, perform the following operations:

[0215] If the Sac300 status is maintained for a period of time exceeding the third time threshold preset by the user, the electronic control unit will issue an engine braking activation command to activate the engine braking; then the Sac500 will be executed.

[0216] If the state of Sac300 is maintained for no longer than the third time threshold, then return and execute Sac400 again.

[0217] The Sac500 electronic control unit acquires engine speed signals in real time.

[0218] Sac600 compares the engine speed signal with a manually preset sixth speed threshold; then, based on the comparison result, performs the following operations:

[0219] If the engine speed signal is higher than the sixth speed threshold, then execute the first engine braking 2, the second engine braking 4, and the third engine braking 7.

[0220] If the engine speed signal is not higher than the sixth speed threshold, then the first engine brake 2, the second engine brake 4, and the third engine brake 7 are turned off, and the fault of being unable to stop normally after power is recorded.

[0221] If there is no driver intervention at present, the active overspeed protection procedure will be executed.

[0222] It should be noted that, as Figure 3 As shown, the present invention mainly implements an engine overspeed protection control method and system. This specific embodiment takes a six-cylinder diesel engine as an example; since the prior art only considers the engine speed threshold and whether the brake pedal is open, the present invention, in addition to considering the engine speed threshold and whether the driver intervenes with the pedal, also considers the vehicle speed signal 3, the accelerator pedal opening signal and the status of ABS.

[0223] In this specific embodiment, the active overspeed protection process includes the following steps:

[0224] Sb100. The electronic control unit acquires engine speed signal, vehicle speed signal, accelerator pedal signal, brake pedal signal, engine status, and ABS status in real time.

[0225] Sb200 determines the current application conditions based on engine speed signal, vehicle speed signal, accelerator pedal signal, brake pedal signal, engine status, and ABS status; then, based on the determination results, it performs the following operations:

[0226] If the current application condition is a combination of engine overspeed protection and main braking, then the active main braking combination sub-process is initiated and executed.

[0227] If the current application condition is to detect engine speed, then start and execute the active engine speed detection subprocess.

[0228] In this specific embodiment, the active main braking combined sub-process specifically includes the following steps:

[0229] Sba100. Based on vehicle speed signal 3, ABS status, and engine status, perform the following operations:

[0230] If the vehicle speed signal 3 is greater than 0, the ABS status is not activated, and the engine status is deceleration fuel cut-off, then the engine speed signal is detected in real time.

[0231] If the vehicle speed signal 3 is not greater than 0, or the ABS is active, or the engine is not in a deceleration fuel cut-off state, then the first engine braking 2, the second engine braking 4, and the third engine braking 7 will not be executed.

[0232] Sba200 compares the engine speed signal with a first speed threshold; then, based on the comparison result, performs the following operations:

[0233] If the engine speed signal is higher than the first speed threshold, and the brake pedal signal is greater than 0, and the duration exceeds the first time threshold, then execute the first engine braking 2, the second engine braking 4, and the third engine braking 7; then execute Sba300.

[0234] If the engine speed signal is not higher than the first speed threshold, or the brake pedal signal is not greater than 0, or the duration does not exceed the first time threshold, then the first engine braking 2, the second engine braking 4, and the third engine braking 7 will not be executed.

[0235] The Sba300 electronic control unit acquires engine speed signals in real time.

[0236] Sba400 compares the engine speed signal with the second speed threshold; then, based on the comparison result, performs the following operations:

[0237] If the engine speed signal is less than the second speed threshold, then the first engine brake 2, the second engine brake 4, and the third engine brake 7 are turned off.

[0238] If the engine speed signal is not less than the second speed threshold, return and execute Sba300 again.

[0239] It should be noted that, based on the detection of the above signals, even without considering vehicle speed and brake pedal intervention, auxiliary braking is still necessary to prevent excessive engine speed and damage to engine components.

[0240] In this specific embodiment, the active engine speed detection subprocess includes the following steps:

[0241] Sbb100. Based on the ABS status, perform the following operations:

[0242] If the ABS is active, the auxiliary braking will not be activated.

[0243] If the ABS status is inactive, then execute Sbb200.

[0244] The Sbb200 electronic control unit acquires engine speed and accelerator pedal signals in real time.

[0245] Sbb300 performs the following operations based on the engine speed signal and accelerator pedal signal:

[0246] If the engine speed signal is greater than the third speed threshold, and the accelerator pedal signal is less than the manually preset third accelerator opening threshold, and the duration exceeds the second time threshold, then execute the first engine braking 2, the second engine braking 4, and the third engine braking 7; then execute Sbb400.

[0247] If the engine speed signal is not greater than the third speed threshold, or the accelerator pedal signal is not less than the third accelerator opening threshold, or the duration does not exceed the second time threshold, then the first engine braking 2, the second engine braking 4, and the third engine braking 7 will not be executed.

[0248] The Sbb400 electronic control unit acquires engine speed signals in real time.

[0249] Sbb500 compares the engine speed signal with the third speed threshold; then, based on the comparison result, performs the following operations:

[0250] If the engine speed signal is less than the third speed threshold, then the first engine brake 2, the second engine brake 4, and the third engine brake 7 are turned off.

[0251] If the engine speed signal is not less than the third speed threshold, return and execute Sbb400 again.

[0252] It should be noted that the above mainly applies to two working conditions:

[0253] The active main braking combined with the sub-process helps reduce brake pad wear and prevents excessive engine speed, thus protecting the engine.

[0254] The active engine speed detection subprocess mainly detects engine speed to prevent abnormally high engine speeds under low throttle conditions. By activating engine braking, the engine speed is reduced to a safe range, thus protecting engine components (driving process / brake pedal intervention).

[0255] In the above detailed description, various features are combined together in a single embodiment to simplify this disclosure. This approach to disclosure should not be construed as reflecting an intention that embodiments of the claimed subject matter require more features than are explicitly stated in each claim. Rather, as reflected in the appended claims, the invention is presented with fewer features than all of the features of the single disclosed embodiment. Therefore, the appended claims are hereby explicitly incorporated into the detailed description, wherein each claim stands alone as a preferred embodiment of the invention.

[0256] The disclosed embodiments have been described above to enable any person skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments without departing from the spirit and scope of this disclosure. Therefore, this disclosure is not limited to the embodiments given herein, but is consistent with the broadest scope of the principles and novel features disclosed in this application.

[0257] The foregoing description includes examples of one or more embodiments. It is certainly impossible to describe all possible combinations of components or methods in order to describe the above embodiments, but those skilled in the art will recognize that further combinations and arrangements of the various embodiments are possible. Therefore, the embodiments described herein are intended to cover all such changes, modifications, and variations that fall within the scope of the appended claims. Furthermore, the term "comprising" as used in the specification or claims is interpreted in a manner similar to the term "including," as interpreted when used as a conjunction in the claims. Additionally, the use of any term "or" in the specification of the claims is intended to mean "non-exclusive or."

[0258] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An engine overspeed protection control method, characterized in that: An engine overspeed protection control system is utilized; the engine overspeed protection control system includes an engine body (1), a first engine brake (2), a vehicle speed signal (3), a second engine brake (4), an engine speed sensor (5), a flywheel (6), a third engine brake (7), an electronic control unit, and a brake pedal signal; wherein: The first engine brake (2) is an in-cylinder brake used to brake the first to third cylinders of the engine body (1); the first engine brake (2) is electrically coupled to the electronic control unit; the first engine brake (2) performs engine braking on the first to third cylinders of the engine body (1) according to the control of the electronic control unit. The second engine brake (4) is an in-cylinder brake used to brake the 4th to 6th cylinders of the engine body (1); the second engine brake (4) is electrically coupled to the electronic control unit; the second engine brake (4) performs engine braking on the 4th to 6th cylinders of the engine body (1) according to the control of the electronic control unit. The third engine brake (7) is an exhaust brake; The engine speed sensor (5) is used to collect engine speed signals; the engine speed sensor (5) is electrically coupled to the electronic control unit and sends the engine speed signals to the electronic control unit; The electronic control unit also receives the vehicle speed signal (3) and the brake pedal signal; The engine overspeed protection control method specifically includes the following steps: S100. Detect key signal; the key signal includes power-on state and power-off state; S200. Perform the following operation based on the key signal: If the key signal is in the power-off state, then the shutdown overspeed protection procedure is executed; If the key signal is in the power-on state, then execute S300; S300. Detect whether there is driver intervention at present; S400. Based on the test results, perform the following operations: If there is driver intervention, the passive overspeed protection procedure will be executed; If there is no driver intervention at present, the active overspeed protection procedure will be executed; The passive overspeed protection process specifically includes the following steps: Sa100. The electronic control unit acquires the engine speed signal, accelerator pedal signal, brake pedal signal, and key signal in real time; Sa200. Based on the engine speed signal, the accelerator pedal signal, the brake pedal signal, and the key signal, the following operations are performed: If the combination of the engine speed signal and the brake pedal signal satisfies the triggering condition of the first passive overspeed protection sub-process, then the first passive overspeed protection sub-process is started and executed. If the combination of the engine speed signal and the accelerator pedal signal satisfies the triggering condition of the second passive overspeed protection sub-process, then the second passive overspeed protection sub-process is started and executed. If the key signal is in the power-down state, then the third passive overspeed protection sub-process is initiated and executed; The active overspeed protection process specifically includes the following steps: Sb100. The electronic control unit acquires the engine speed signal, the vehicle speed signal (3), the accelerator pedal signal, the brake pedal signal, the engine status, and the ABS status in real time; Sb200. Based on the engine speed signal, the vehicle speed signal (3), the accelerator pedal signal, the brake pedal signal, the engine status, and the ABS status, determine the current application condition; then, based on the determination result, perform the following operations: If the current application condition is a combination of engine overspeed protection and main braking, then the active main braking combination sub-process is started and executed. If the current application condition is to detect engine speed, then start and execute the active engine speed detection subprocess; The shutdown overspeed protection process specifically includes the following steps: Sc100. The electronic control unit acquires the key signal and the vehicle speed signal (3) in real time; and then performs the following operations based on the key signal and the vehicle speed signal (3): If the key signal is in the power-off state and the vehicle speed signal (3) is less than the first vehicle speed threshold preset by the user, then Sc200 is executed. If the key signal is in the power-on state and the vehicle speed signal (3) is not less than the first vehicle speed threshold, then return and execute Sc100 again; Sc200. The electronic control unit acquires the engine speed signal in real time; Sc300. Based on the engine speed signal, perform the following operations: If the engine speed signal is greater than the fifth speed threshold, then the first engine braking (2), the second engine braking (4), and the third engine braking (7) are executed. If the engine speed signal is greater than the sixth speed threshold, and if the engine speed signal is less than the fifth speed threshold, then execute the first engine braking (2), the second engine braking (4), and the third engine braking (7); then execute Sc400; Sc400. The electronic control unit acquires the engine speed signal in real time; Sc500. Based on the engine speed signal, perform the following operations: If the engine speed signal is greater than the sixth speed threshold, then return to and execute Sc400 again; If the engine speed signal is less than the sixth speed threshold, then the first engine brake (2), the second engine brake (4), and the third engine brake (7) are turned off; then the engine failure to stop normally is recorded.

2. The engine overspeed protection control method according to claim 1, characterized in that: The first passive overspeed protection sub-process specifically includes the following steps: Saa100. The electronic control unit acquires the engine speed signal and the brake pedal signal in real time; Based on the vehicle speed signal and ABS status, the following operations are performed: If the vehicle speed signal is greater than 0 and the ABS status is inactive, then execute Saa200; Saa200. Compare the engine speed signal with a manually preset first speed threshold; then, based on the comparison result, perform the following operations: If the engine speed signal is higher than the first speed threshold, then execute Saa300; If the engine speed signal is not higher than the first speed threshold, return and execute Saa100 again; Saa300. Detects the brake pedal signal; then, based on the detection result, performs the following operations: If the brake pedal signal indicates that the driver has pressed the brake pedal, then execute Saa400; If the brake pedal signal indicates that the driver has not pressed the brake pedal, then return and execute Saa100 again; Saa400. Statistically determine the duration of states from Saa200 to Saa300; then, based on the statistical results, perform the following operations: If the state of Saa200 to Saa300 is maintained for a time exceeding the first time threshold preset by the user, the electronic control unit will issue an engine braking activation command to activate the engine braking; then Saa500 will be executed. If the state duration of Saa200 to Saa300 does not exceed the first time threshold, then return and execute Saa400 again; Saa500. The electronic control unit acquires the engine speed signal in real time; Saa600. Compare the engine speed signal with a manually preset second speed threshold; then, based on the comparison result, perform the following operations: If the engine speed signal is higher than the second speed threshold, then execute Saa700; If the engine speed signal is not higher than the second speed threshold, the engine braking will automatically disengage. Saa700. Compare the brake pedal signal with a manually preset brake pedal opening threshold; then, based on the comparison result, perform the following operations: If the brake pedal signal is higher than the brake pedal opening threshold, then the first engine braking, the second engine braking, and the third engine braking are executed. If the brake pedal signal is not higher than the brake pedal opening threshold, then the auxiliary brake is turned off.

3. The engine overspeed protection control method according to claim 2, characterized in that: The second passive overspeed protection sub-process specifically includes the following steps: Sab100. The electronic control unit acquires the engine speed signal and the accelerator pedal signal in real time; Based on the ABS status, perform the following operations: If the ABS state is inactive, then execute Sab200; Sab200. Compare the engine speed signal with a manually preset third speed threshold; then, based on the comparison result, perform the following operations: If the engine speed signal is higher than the third speed threshold, then execute Sab300; If the engine speed signal is not higher than the third speed threshold, return and execute Sab100 again; Sab300. Compare the accelerator pedal signal with a manually preset first accelerator opening threshold; then, based on the comparison result, perform the following operations: If the accelerator pedal signal is not higher than the first accelerator opening threshold, then execute Sab400; If the accelerator pedal signal is higher than the first accelerator opening threshold, return and execute Sab100 again; Sab400. Statistically determine the duration of states maintained by Sab200 to Sab300; then, based on the statistical results, perform the following operations: If the state of Sab200 to Sab300 is maintained for a longer period than the second time threshold preset by the user, the electronic control unit will issue an activation command for engine braking, which will activate the first engine brake, the second engine brake, and the third engine brake; then Sab500 will be executed. If the state duration of Sab200 to Sab300 does not exceed the second time threshold, then return and execute Sab400 again; Sab500. The electronic control unit acquires the engine speed signal and the accelerator pedal signal in real time; Sab600. Compare the engine speed signal with a manually preset fourth speed threshold; then, based on the comparison result, perform the following operations: If the engine speed signal is higher than the fourth speed threshold, then execute Sab700; If the engine speed signal is not higher than the fourth speed threshold, then engine braking is automatically disengaged; Sab700. Compare the accelerator pedal signal with a manually preset second accelerator opening threshold; then, based on the comparison result, perform the following operations: If the accelerator pedal signal is higher than the second accelerator opening threshold, engine braking will automatically disengage. If the accelerator pedal signal is not higher than the second accelerator opening threshold, then the first engine brake, the second engine brake, and the third engine brake are deactivated.

4. The engine overspeed protection control method according to claim 3, characterized in that: The third passive overspeed protection sub-process specifically includes the following steps: Sac100. The vehicle speed signal performs the following operations: If the vehicle speed signal is less than 5 km / h, then execute Sac200; Sac200. When the key signal is in the power-off state, the electronic control unit acquires the engine speed signal in real time; Sac300. Compare the engine speed signal with a manually preset fifth speed threshold; then, based on the comparison result, perform the following operations: If the engine speed signal is higher than the fifth speed threshold, then Sac400 is executed; If the engine speed signal is not higher than the fifth speed threshold, then return and execute Sac200 again; Sac400. Calculate the state maintenance time of Sac300, and based on the results, perform the following operations: If the Sac300 state is maintained for a longer period than the third time threshold preset by the user, the electronic control unit will issue an engine braking activation command to activate the engine braking; then Sac500 will be executed. If the state duration of Sac300 does not exceed the third time threshold, then return and execute Sac400 again; Sac500. The electronic control unit acquires the engine speed signal in real time; Sac600. Compare the engine speed signal with a manually preset sixth speed threshold; then, based on the comparison result, perform the following operations: If the engine speed signal is higher than the sixth speed threshold, then the first engine braking, the second engine braking, and the third engine braking are executed; if the engine speed signal is not higher than the sixth speed threshold, then the engine braking is turned off, and the fault of failure to stop the engine normally is recorded.

5. The engine overspeed protection control method according to claim 4, characterized in that: The active main braking combined sub-process specifically includes the following steps: Sba100. Based on the vehicle speed signal (3), the ABS status, and the engine status, the following operations are performed: If the vehicle speed signal (3) is greater than 0, the ABS status is not activated, and the engine status is deceleration fuel cut-off, then the engine speed signal is detected in real time. If the vehicle speed signal (3) is not greater than 0, or the ABS is active, or the engine is not in a deceleration fuel cut-off state, then the first engine braking (2), the second engine braking (4), and the third engine braking (7) will not be executed. Sba200. Compare the engine speed signal with the first speed threshold; then, based on the comparison result, perform the following operations: If the engine speed signal is higher than the first speed threshold, and the brake pedal signal is greater than 0, and the duration exceeds the first time threshold, then the first engine braking (2), the second engine braking (4), and the third engine braking (7) are executed; then Sba300 is executed. If the engine speed signal is not higher than the first speed threshold, or the brake pedal signal is not greater than 0, or the duration does not exceed the first time threshold, then the first engine braking (2), the second engine braking (4), and the third engine braking (7) are not executed. Sba300. The electronic control unit acquires the engine speed signal in real time; Sba400. Compare the engine speed signal with the second speed threshold; then, based on the comparison result, perform the following operations: If the engine speed signal is less than the second speed threshold, then the first engine brake (2), the second engine brake (4), and the third engine brake (7) are turned off. If the engine speed signal is not less than the second speed threshold, then return and execute Sba300 again.

6. The engine overspeed protection control method according to claim 5, characterized in that: The active engine speed detection subprocess specifically includes the following steps: Sbb100. Based on the ABS status, perform the following operations: If the ABS status is active, the auxiliary braking will not be activated; If the ABS status is inactive, then execute Sbb200; Sbb200. The electronic control unit acquires the engine speed signal and the accelerator pedal signal in real time; Sbb300. Based on the engine speed signal and the accelerator pedal signal, perform the following operations: If the engine speed signal is greater than the third speed threshold, and the accelerator pedal signal... If the throttle opening is less than the manually preset third throttle opening threshold and the duration exceeds the second time threshold, then the first engine braking (2), the second engine braking (4), and the third engine braking (7) are executed; then Sbb400 is executed. If the engine speed signal is not greater than the third speed threshold, or the accelerator pedal signal If the throttle opening threshold is not less than the third throttle opening threshold, or the duration does not exceed the second time threshold, then the first engine braking (2), the second engine braking (4), and the third engine braking (7) will not be executed. Sbb400. The electronic control unit acquires the engine speed signal in real time; Sbb500. Compare the engine speed signal with the third speed threshold; then, based on the comparison result, perform the following operations: If the engine speed signal is less than the third speed threshold, then the first engine brake (2), the second engine brake (4), and the third engine brake (7) are turned off. If the engine speed signal is not less than the third speed threshold, then return and execute Sbb400 again.

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