Vehicle fuel saving method for automatically adjusting driving mode

Abstract

The present invention provides a vehicle fuel saving method for automatically adjusting driving modes. When the driver selects the standard (Normal) driving mode, the vehicle is driven at a constant speed or decelerated by switching the shift MAP. When the driver's power demand is not strong, the engine is operated at a low speed, thereby realizing the function of fuel saving. The present invention is based on the automatic switching driving mode. When the vehicle driving mode is the standard mode, the shift MAP of the transmission controller is switched to reduce the engine speed through the algorithm of intelligent switching driving mode, thereby saving fuel for the user without affecting the vehicle power. The protection points of the present invention are the algorithm of intelligent switching driving mode and the algorithm of saving fuel.

Description

Technical Field

[0001] The invention belongs to the technical field of vehicle fuel saving, and in particular relates to a vehicle fuel saving method for automatically adjusting a driving mode. Background Art

[0002] ECU: Engine Control Unit

[0003] TCU: Transmission Control Unit

[0004] MAP: Mapping diagram, in this article, refers to the relationship between the accelerator pedal and torque mapping diagram

[0005] The vehicle fuel saving method based on automatic switching of driving modes is intended to achieve fuel saving by shifting MAP when the vehicle is moving at a constant speed or decelerating when the driver selects the standard (Normal) driving mode.

[0006] When the driver is driving the vehicle normally, there will definitely be a condition where the vehicle needs to brake, that is, slow down. There is also a high probability that the vehicle needs to maintain a constant speed. In these two conditions, the driver's power request for the vehicle is very small or not that strong. At this time, the gear shift MAP of the transmission is switched to reduce the engine speed, so that the engine is in a low fuel consumption state, thereby achieving the purpose of saving fuel. When the vehicle accelerates, the driver has a strong demand for vehicle power. The gear shift MAP of the transmission control unit TCU is switched back to the gear shift MAP during standard driving, so that the engine can maintain a high speed at a certain speed. This does not affect the power output of the vehicle, thereby switching the driving mode without feeling, and also achieving the purpose of saving fuel.

[0007] There is no intelligent driving mode switching strategy in the vehicles currently on the market. They only distinguish the driving modes of the vehicles, such as Normal, ECO, Sport, Snow, etc. The power and fuel consumption of vehicles in different driving modes are not the same. When users choose the Normal mode (generally the default is also the standard driving mode), they do not need strong power output all the time. How to save fuel for users in the default mode without affecting the power of the vehicle and achieve the effect of imperceptible fuel saving? There is no such plan or strategy in the vehicles currently on the market. Summary of the invention

[0008] The technical problem to be solved by the present invention is to provide a vehicle fuel saving method for automatically adjusting a driving mode, so as to realize a fuel saving function.

[0009] The technical solution adopted by the present invention to solve the above technical problems is: a vehicle fuel saving method for automatically adjusting the driving mode, comprising the following steps:

[0010] S1: Determine whether the driving mode is in the standard Normal mode, if not, exit; if yes, proceed to the next step;

[0011] S2: Determine whether the intelligent fuel saving mode is on, if not, exit; if yes, proceed to the next step;

[0012] S3: The engine electronic control unit ECU determines whether the accelerator pedal request torque is less than or equal to the current vehicle speed resistance torque + the first switching hysteresis Δ1. If so, the shift map MAP is switched to the fuel-saving ECO mode shift map MAP; if not, the next step is executed;

[0013] S4: The engine electronic control unit ECU determines whether the accelerator pedal request torque is greater than the current vehicle speed resistance torque + the second switching hysteresis Δ2. If so, the shift map MAP is switched to the standard Normal mode shift map MAP; otherwise, the fuel-saving ECO mode shift map MAP is maintained.

[0014] According to the above scheme, the prerequisites for turning on the intelligent fuel saving mode are:

[0015] At each vehicle speed, there is a resistance torque T corresponding to the current vehicle speed. fric ; The vehicle has different shift maps MAP for different driving modes including Sport mode, Normal mode and ECO mode; the intelligent fuel-saving mode is only turned on in Normal mode.

[0016] Furthermore, when the vehicle is in the standard Normal mode, the gear shift map MAP of the transmission control unit TCU is:

[0017] 1-2 2-3 3-4 4-5 5-6 Accelerator pedal opening 2-1 3-2 4-3 5-4 6-5 12.5 21 33 47.5 67 0 4.5 19 28 42 61 12.5 21 33 47.5 67 5 9 18 28 42 61 12.5 21 33 47.5 67 10 9 18 28 42 61 12.5 21 33 47.5 67 15 9 18 28 42 61 13.5 22 34 49.5 70 20 9 18 28 42 61 16.5 25 38 55.5 80 30 11 19 31 44 63 19.5 30 46 67.5 100 40 13 22 35 51 72 24.5 37 57 83 125 50 15 26 41 60 90 31 46 69 105 156 60 16 32 51 77 110 32 51 82 123 197 70 16 40 62 94 138 33 52 90 135 197 80 16 40 76 112 166 33 52 91 136 197 90 16 40 80 124 180 33 52 91 136 197 98 16 40 80 124 180 33 52 91 136 197 100 16 40 80 124 180

[0018] Furthermore, when the vehicle is in the fuel-saving ECO mode, the gear shift map MAP of the transmission control unit TCU is:

[0019]

[0020]

[0021] Furthermore, when the vehicle is in the Sport mode, the gear shift map MAP of the transmission control unit TCU is:

[0022] 1-2 2-3 3-4 4-5 5-6 Accelerator pedal opening 2-1 3-2 4-3 5-4 6-5 16 24 40 60 85 0 12 21 35 56 78 16 24 40 60 85 5 12 21 35 56 78 16 24 40 60 85 10 12 21 35 56 78 16 24 40 60 85 15 12 21 36 57 78 18 26 42 64 92 20 13 22 38 58 81 22 32 50 76 113 30 14 26 43 65 97 25 37 59 90 130 40 16 31 51 75 111 29 42 68 103 145 50 17 36 58 87 126 33 47 77 115 164 60 18 40 67 100 143 35 51 84 126 180 70 19 44 75 114 160 36 54 89 133 195 80 20 46 82 124 178 36 54 92 136 197 90 20 48 85 128 180 36 54 92 136 197 98 20 48 85 128 180 36 54 92 136 197 100 20 48 85 128 180

[0023] According to the above scheme, in step S2, the specific steps are:

[0024] If the intelligent fuel saving mode is turned on, the accelerator pedal MAP of the engine electronic control unit ECU remains unchanged and remains in the standard Normal mode; at the same time, the engine electronic control unit ECU sends information back to the transmission control unit TCU to keep the standard Normal mode unchanged.

[0025] According to the above scheme, in step S3, the specific steps are:

[0026] S31: The engine electronic control unit ECU compares the accelerator pedal request torque with the coasting resistance torque, and sends the fuel-saving ECO mode to the transmission control unit TCU, so that the transmission control unit TCU changes the shift map MAP;

[0027] S32: The gear shift map MAP changes. The gearbox control unit TCU has a gear switching scenario. According to the vehicle speed and the opening of the accelerator pedal at this time, the gearbox control unit TCU switches from a low gear to a high gear, and the engine speed is reduced. The engine is now in the universal characteristic of the fuel-saving ECO mode to achieve the purpose of fuel saving.

[0028] A computer storage medium stores a computer program that can be executed by a computer processor. The computer program executes a vehicle fuel saving method for automatically adjusting a driving mode.

[0029] The beneficial effects of the present invention are:

[0030] 1. The present invention provides a vehicle fuel saving method for automatically adjusting driving modes. When the driver selects the normal driving mode, the vehicle is driven at a constant speed or decelerated by switching the shift MAP. When the driver does not have a strong demand for power, the engine is operated at a low speed, thereby achieving a fuel saving function.

[0031] 2. The present invention is based on automatic switching of driving modes. When the vehicle driving mode is the standard mode, the algorithm for intelligently switching driving modes is used to switch the shift MAP of the transmission controller to reduce the engine speed, thereby saving fuel for users without affecting the power of the vehicle.

[0032] 3. The protection points of the present invention are the algorithm for intelligently switching driving modes and the algorithm for saving fuel. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a flow chart of an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0035] See also Figure 1 The premise of the intelligent fuel saving algorithm of the embodiment of the present invention is:

[0036] 1) At each vehicle speed, there is a resistance torque T corresponding to the current vehicle speed. fric .

[0037] 2) When the vehicle is in different driving modes such as Sport, Normal, and ECO, the transmission control unit (TCU) has different shift maps MAP.

[0038] 3) The intelligent fuel-saving algorithm is only effective in the standard (Normal) mode. Because the driver has already developed a driving tendency when choosing the sports mode and the fuel-saving mode: choosing the sports mode means that the driver has a strong demand for the vehicle's power and is not concerned about fuel consumption at this time. Choosing the fuel-saving mode means that the driver is more concerned about the vehicle's fuel economy at this time and has less demand for power. Therefore, when the driver chooses these two modes, the driving mode will not be switched intelligently.

[0039] When the user is driving at a constant speed at a certain speed, if the intelligent fuel saving mode is turned on at this time, the engine electronic control unit ECU determines that the driver's request torque is equal to or less than the resistance torque + Δ1 at this speed, and then switches the shift mode to the shift map MAP in the fuel saving ECO mode. At this time, due to the change of the shift map MAP, the gear position of the transmission control unit TCU has a switching scenario, that is, according to the vehicle speed and the opening of the accelerator pedal at this time, the transmission control unit TCU may switch the gear position from a low gear to a high gear, and the engine speed is reduced. The engine is in the universal characteristics of the fuel saving ECO mode at this time, thereby achieving the purpose of fuel saving. Tables 1, 2 and 3 respectively give the shift map MAP of the transmission control unit (TCU) of a certain model in standard (Normal), fuel saving (ECO) and sports (Sport). When the user steps on the accelerator deeply to obtain more power, the standard ECU of the engine electronic control unit determines whether the driver's request torque is greater than the resistance torque + Δ2 at this speed. If it is greater, it switches back to the standard Normal mode. In order to avoid vehicle jerking caused by frequent switching of the gear shift map MAP, switching hysteresis Δ1 and Δ2 are specified here, and Δ1 and Δ2 are calibrable values.

[0040] Table 1

[0041] 1-2 2-3 3-4 4-5 5-6 Accelerator pedal (unit: opening) 2-1 3-2 4-3 5-4 6-5 12.5 21 33 47.5 67 0 4.5 19 28 42 61 12.5 21 33 47.5 67 5 9 18 28 42 61 12.5 21 33 47.5 67 10 9 18 28 42 61 12.5 21 33 47.5 67 15 9 18 28 42 61 13.5 22 34 49.5 70 20 9 18 28 42 61 16.5 25 38 55.5 80 30 11 19 31 44 63 19.5 30 46 67.5 100 40 13 22 35 51 72 24.5 37 57 83 125 50 15 26 41 60 90 31 46 69 105 156 60 16 32 51 77 110 32 51 82 123 197 70 16 40 62 94 138 33 52 90 135 197 80 16 40 76 112 166 33 52 91 136 197 90 16 40 80 124 180 33 52 91 136 197 98 16 40 80 124 180 33 52 91 136 197 100 16 40 80 124 180

[0042] Table 2

[0043]

[0044]

[0045] Table 3

[0046] 1-2 2-3 3-4 4-5 5-6 Accelerator pedal (unit: opening) 2-1 3-2 4-3 5-4 6-5 16 24 40 60 85 0 12 21 35 56 78 16 24 40 60 85 5 12 21 35 56 78 16 24 40 60 85 10 12 21 35 56 78 16 24 40 60 85 15 12 21 36 57 78 18 26 42 64 92 20 13 22 38 58 81 22 32 50 76 113 30 14 26 43 65 97 25 37 59 90 130 40 16 31 51 75 111 29 42 68 103 145 50 17 36 58 87 126 33 47 77 115 164 60 18 40 67 100 143 35 51 84 126 180 70 19 44 75 114 160 36 54 89 133 195 80 20 46 82 124 178 36 54 92 136 197 90 20 48 85 128 180 36 54 92 136 197 98 20 48 85 128 180 36 54 92 136 197 100 20 48 85 128 180

[0047] The user turns on the intelligent fuel saving mode. The engine electronic control unit ECU sends the Normal or ECO driving mode to the transmission control unit TCU based on the comparison between the accelerator pedal request torque and the coasting resistance torque, so that the transmission control unit TCU changes the shift map MAP. In order to change and only change the shift map MAP, the following agreement is made:

[0048] 1) After the intelligent fuel saving mode is turned on, the accelerator pedal MAP of the engine electronic control unit ECU remains unchanged and remains at the accelerator pedal MAP in the normal mode. This is to avoid great difficulties in fuel consumption analysis when both the accelerator pedal MAP and the shift MAP are switched.

[0049] 2) In some models, the driving mode button of the vehicle is connected to the engine electronic control unit ECU. After the engine electronic control unit ECU makes a judgment, it sends it to the transmission control unit TCU through the CAN bus. The driving mode sent by the transmission control unit TCU after final processing is the final driving mode of the whole vehicle. After turning on the intelligent fuel saving mode, in order to avoid the engine electronic control unit ECU intelligently switching to the economy (ECO) mode, the driving mode of the whole vehicle changes to ECO and causes the intelligent fuel saving to exit, the engine electronic control unit ECU should send back the controller that sends the intelligent fuel saving mode when the intelligent fuel saving mode is turned on, and keep the Normal mode unchanged.

[0050] The fuel saving rate calculation of the intelligent fuel saving algorithm is to time the switch to the ECO shift MAP when the intelligent fuel saving mode is turned on. According to the universal characteristics of the C15TDR engine, the comprehensive fuel consumption in the ECO mode is 98% of that in the Normal mode, that is, the fuel saving rate is 2%. The fuel saved after the intelligent fuel saving mode is turned on = (t_eco / t_cycle)*IC_AvgFuelConsumed*trip_a*2%.

[0051] Among them, t_eco refers to the time when the vehicle intelligently switches to ECO mode, t_cycle is the total time of this trip, IC_AvgFuelConsumed is the average fuel consumption displayed on the instrument, and trip_a is the subtotal mileage of this trip.

[0052] The above embodiments are only used to illustrate the design ideas and features of the present invention, and their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. The protection scope of the present invention is not limited to the above embodiments. Therefore, any equivalent changes or modifications made based on the principles and design ideas disclosed by the present invention are within the protection scope of the present invention.

Claims

1. A vehicle fuel saving method for automatically adjusting driving modes, characterized in that: The following steps are involved: S1: Determine whether the driving mode is in the standard Normal mode, if not, exit; if yes, proceed to the next step; S2: Determine whether the intelligent fuel saving mode is on, if not, exit; if yes, proceed to the next step; S3: The engine electronic control unit ECU determines whether the accelerator pedal request torque is less than or equal to the current vehicle speed resistance torque + the first switching hysteresis Δ1. If so, the shift map MAP is switched to the fuel-saving ECO mode shift map MAP; if not, the next step is executed; S4: The engine electronic control unit ECU determines whether the accelerator pedal request torque is greater than the current vehicle speed resistance torque + the second switching hysteresis Δ2. If so, the shift map MAP is switched to the standard Normal mode shift map MAP; otherwise, the fuel-saving ECO mode shift map MAP is maintained.

2. The vehicle fuel saving method for automatically adjusting driving modes according to claim 1, characterized in that: The prerequisites for turning on the intelligent fuel saving mode are: At each vehicle speed, there is a resistance torque T corresponding to the current vehicle speed. fric ; The vehicle has different shift maps MAP for different driving modes including Sport mode, Normal mode and ECO mode; the intelligent fuel-saving mode is only turned on in Normal mode.

3. The vehicle fuel saving method for automatically adjusting driving modes according to claim 2, characterized in that: When the vehicle is in the standard Normal mode, the gear shift map MAP of the transmission control unit TCU is: 。 4. The vehicle fuel saving method for automatically adjusting driving modes according to claim 2, characterized in that: When the vehicle is in fuel-saving ECO mode, the gear shift map MAP of the transmission control unit TCU is: 。 5. The vehicle fuel saving method for automatically adjusting driving modes according to claim 2, characterized in that: When the vehicle is in Sport mode, the gear shift map MAP of the transmission control unit TCU is: 。 6. The vehicle fuel saving method for automatically adjusting driving modes according to claim 1, characterized in that: In the step S2, the specific steps are: If the intelligent fuel saving mode is turned on, the accelerator pedal MAP of the engine electronic control unit ECU remains unchanged and remains in the standard Normal mode; at the same time, the engine electronic control unit ECU sends information back to the transmission control unit TCU to keep the standard Normal mode unchanged.

7. The vehicle fuel saving method for automatically adjusting driving modes according to claim 1, characterized in that: In the step S3, the specific steps are: S31: The engine electronic control unit ECU compares the accelerator pedal request torque with the coasting resistance torque, and sends the fuel-saving ECO mode to the transmission control unit TCU, so that the transmission control unit TCU changes the shift map MAP; S32: The gear shift map MAP changes. The gearbox control unit TCU has a gear switching scenario. According to the vehicle speed and the opening of the accelerator pedal at this time, the gearbox control unit TCU switches from a low gear to a high gear, and the engine speed is reduced. The engine is now in the universal characteristic of the fuel-saving ECO mode to achieve the purpose of fuel saving.

8. A computer storage medium, characterized in that: A computer program executable by a computer processor is stored therein, and the computer program executes a vehicle fuel saving method for automatically adjusting a driving mode as described in any one of claims 1 to 7.

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