Commercial vehicle electric control thermostat control method

Abstract

The invention discloses a control method for an electric control thermostat of a commercial vehicle, relates to the technical field of thermostats, and solves the technical problem that an existing electric control thermostat does not have a universal control method temporarily. The method comprises the steps that the thermostat opening degree required by an engine, retarder parameters, the retarder state, the working state of a cooling liquid temperature sensor, the working state of the engine and engine operation parameters are obtained, and the thermostat opening degree required by the retarder is obtained according to the thermostat opening degree required by the engine, the retarder parameters and the retarder state; the required opening degree of the electric control thermostat is obtained through the required opening degree of the thermostat of the retarder, the working state of the cooling liquid temperature sensor and the working state of the engine, and the heating duty ratio of the electric control thermostat is obtained through the required opening degree of the electric control thermostat and the operation parameters of the engine. And the electric control thermostat is controlled through the required opening degree of the electric control thermostat and the heating duty ratio of the electric control thermostat. The regulation and control capability of the engine cooling system on the temperature of the cooling liquid is effectively improved, and the reliability and the economical efficiency are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of thermostats, and more particularly to a control method for an electronically controlled thermostat of a commercial vehicle. Background Art

[0002] At present, electronically controlled diesel engines have been fully popularized, and their performance in all aspects is better than that of traditional mechanical oil pump engines. Most of the existing electronically controlled diesel engines use paraffin thermostats. The working principle of paraffin thermostats is to control the opening of large and small circulation valves through the thermal expansion and contraction of paraffin. However, the use of paraffin thermostats will lead to the following disadvantages: the opening change of the paraffin thermostat is only passively affected by the engine water temperature, and there is a lag phenomenon, which leads to poor local cooling effect of the engine and mechanical wear of the engine; in high-altitude areas, due to the low atmospheric pressure, the boiling point of the engine coolant is reduced, and the thermal expansion and contraction characteristics of the paraffin thermostat are almost unchanged, which makes the engine coolant easy to boil and the engine water pump is prone to cavitation.

[0003] In recent years, in order to avoid the shortcomings of traditional paraffin thermostats, domestic commercial vehicles have been gradually developing electric heating thermostats and electronic thermostats, but there is currently no universal control method for electric heating thermostats and electronic thermostats. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a control method for an electronically controlled thermostat for a commercial vehicle in view of the deficiencies in the prior art, thereby solving the technical problem that there is no universal control method for the existing electronically controlled thermostat.

[0005] A commercial vehicle electronically controlled thermostat control method disclosed in the present invention comprises the following steps: obtaining an engine required thermostat opening, a retarder parameter, a retarder state, a coolant temperature sensor working state, an engine working state and an engine operating parameter; obtaining a retarder required thermostat opening according to the engine required thermostat opening, the retarder parameter and the retarder state; obtaining an electronically controlled thermostat required opening according to the retarder required thermostat opening, the coolant temperature sensor working state and the engine operating state; obtaining an electronically controlled thermostat heating duty cycle according to the electronically controlled thermostat required opening and the engine operating parameter; and controlling the electronically controlled thermostat according to the electronically controlled thermostat required opening and the electronically controlled thermostat heating duty cycle.

[0006] As a further improvement, the method for obtaining the engine demand thermostat opening is to obtain the engine demand thermostat basic opening, environmental parameters and heating status, correct the engine demand thermostat basic opening according to the environmental parameters to obtain the thermostat demand opening, obtain the heating demand thermostat opening according to the heating status and the thermostat demand opening, and obtain the engine demand thermostat opening according to the heating demand thermostat opening and the engine starting process.

[0007] Furthermore, the method for obtaining the basic opening of the engine demand thermostat is to set a cycle, obtain the state of the basic map selection switch of the engine operating parameters, the engine water temperature and the actual engine torque within the cycle, and when the basic map selection switch is in the off state, calibrate the basic opening of the engine demand thermostat according to the engine water temperature and the actual engine torque;

[0008] When the basic pulse spectrum selection switch is in the on state, the engine water temperature change rate is obtained, and the first opening value and the second opening value are calibrated by the engine water temperature and the actual engine torque. When the engine water temperature change rate is less than the preset temperature change rate threshold, the engine demand thermostat basic opening is the first opening value; when the engine water temperature change rate is greater than the temperature change rate threshold, the engine demand thermostat basic opening is the second opening value; when the engine water temperature change rate is equal to the temperature change rate threshold, the engine demand thermostat basic opening is the engine demand thermostat basic opening of the previous cycle.

[0009] Furthermore, the method of correcting the basic opening of the engine required thermostat by the environmental parameters to obtain the required thermostat opening is to obtain the current position slope, the ambient pressure and the ambient temperature in the environmental parameters, and calibrate the current position slope and the preset slope-opening curve to obtain the first thermostat opening correction value;

[0010] The second thermostat opening correction value is obtained by calibrating the engine water temperature and the engine water temperature change rate;

[0011] Obtaining the current vehicle speed, and obtaining a third thermostat opening correction value by calibrating the current vehicle speed and the engine water temperature;

[0012] The fourth thermostat opening correction value is obtained by calibrating the ambient pressure and ambient temperature;

[0013] The engine required thermostat basic opening, the first thermostat opening correction value, the second thermostat opening correction value, the third thermostat opening correction value and the fourth thermostat opening correction value are added together to obtain the required thermostat opening.

[0014] Furthermore, the method for obtaining the heater demand thermostat opening through the heater state and the thermostat demand opening is that when the heater state is on, the heater demand thermostat opening is calibrated by the engine water temperature and a preset water temperature-opening curve; when the heater state is off, the heater demand thermostat opening is the thermostat demand opening.

[0015] Furthermore, the method for obtaining the engine demand thermostat opening according to the heating demand thermostat opening and the engine starting process is:

[0016] The engine running time after starting is obtained during the engine starting process. When the engine running time after starting is less than or equal to a preset running time calibration value and the engine water temperature is greater than or equal to a preset water temperature calibration value, the engine demand thermostat opening is equal to a preset engine demand thermostat opening standard value; otherwise, the engine demand thermostat opening is equal to the heater demand thermostat opening.

[0017] Furthermore, the method for obtaining the required retarder thermostat opening according to the engine required thermostat opening, the retarder parameter and the retarder state includes:

[0018] The retarder activation state in the retarder state is obtained. When the retarder activation state is a preset first activation state value, the retarder required thermostat opening is equal to the engine required thermostat opening; when the retarder activation state is a preset second activation state value, the retarder temperature, the retarder gear position and the retarder actual torque percentage in the retarder parameters are obtained. The first retarder opening value is obtained by calibrating the retarder temperature and the retarder gear position. The retarder actual torque percentage and the preset torque percentage are used to calibrate the retarder gear position. The second retarder opening value is calibrated by the torque percentage-opening curve, and the first retarder opening value and the second retarder opening value are added to obtain the retarder required thermostat opening; when the retarder activation state is a preset third activation state value, the retarder required thermostat opening is obtained by calibrating the retarder temperature and the retarder actual torque percentage; when the retarder activation state is a preset fourth activation state value, the retarder required thermostat opening is obtained by calibrating the retarder actual torque percentage and the retarder gear.

[0019] Furthermore, the method for obtaining the required retarder thermostat opening according to the engine required thermostat opening, the retarder parameter and the retarder state also includes:

[0020] When the retarder actual torque percentage is less than a preset torque percentage threshold, the retarder required thermostat opening is equal to the engine required thermostat opening; otherwise, the retarder required thermostat opening is obtained by calibrating the retarder temperature and the retarder actual torque percentage.

[0021] Furthermore, the method for obtaining the required opening of the electronically controlled thermostat by using the required opening of the retarder thermostat, the working state of the coolant temperature sensor and the working state of the engine is:

[0022] When the engine is in shutdown mode, the required opening of the electronically controlled thermostat is a preset default required opening for shutdown of the engine;

[0023] When the engine is in a non-stop state and the coolant temperature sensor is in a fault state, the required opening of the electronically controlled thermostat is a preset coolant temperature sensor fault default opening;

[0024] When the engine operating state is a non-shutdown state and the coolant temperature sensor is in a normal working state, the electronically controlled thermostat required opening is the retarder required thermostat opening.

[0025] Furthermore, the method for obtaining the heating duty cycle of the electronically controlled thermostat is to obtain the battery voltage of the whole vehicle and the engine water temperature in the engine operating parameters, calibrate the required heating power of the electronically controlled thermostat by the engine water temperature and the required opening of the electronically controlled thermostat, calibrate the power correction coefficient by the battery voltage of the whole vehicle and a preset voltage-power coefficient curve, multiply the required heating power by the correction coefficient to obtain the required heating corrected power, and calibrate the heating duty cycle of the electronically controlled thermostat by the required heating corrected power and the preset power-duty cycle curve.

[0026] Beneficial Effects

[0027] The advantages of the present invention are:

[0028] The present invention obtains the required thermostat opening of the retarder according to the required thermostat opening of the engine, the retarder parameters and the retarder state, obtains the required opening of the electronically controlled thermostat according to the required thermostat opening of the retarder, the working state of the coolant temperature sensor and the working state of the engine, obtains the heating duty cycle of the electronically controlled thermostat according to the required opening of the electronically controlled thermostat and the engine operating parameters, controls the electronically controlled thermostat according to the required opening of the electronically controlled thermostat and the heating duty cycle of the electronically controlled thermostat, realizes the control of the electronically controlled thermostat including the electric heating thermostat and the electronic thermostat, effectively improves the control capability of the engine cooling system on the coolant temperature, and improves the reliability and economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A flow chart for obtaining the required opening of the electronically controlled thermostat in the control method of the present invention;

[0030] Figure 2 A flow chart for obtaining a basic opening of an engine required thermostat in a control method of the present invention;

[0031] Figure 3 A flow chart for obtaining the required thermostat opening in the control method of the present invention;

[0032] Figure 4 A flow chart for obtaining the opening degree of the warm air demand thermostat in the control method of the present invention;

[0033] Figure 5A flow chart for obtaining the engine required thermostat opening in the control method of the present invention;

[0034] Figure 6 A flow chart of obtaining the required thermostat opening of the retarder in the control method of the present invention;

[0035] Figure 7 The present invention is a flow chart for obtaining the heating duty cycle of the electric heating thermostat in the control method of the present invention. DETAILED DESCRIPTION

[0036] The present invention will be further described below in conjunction with the embodiments, but it does not constitute any limitation to the present invention. Any limited number of modifications made by anyone within the scope of the claims of the present invention are still within the scope of the claims of the present invention.

[0037] See also Figure 1-Figure 7 , a commercial vehicle electronically controlled thermostat control method of the present invention comprises, step 1: obtaining the engine required thermostat opening, retarder parameters and retarder status, coolant temperature sensor working status, engine working status and engine operating parameters.

[0038] The method for obtaining the engine demand thermostat opening is to obtain the engine demand thermostat basic opening, environmental parameters and heating status, correct the engine demand thermostat basic opening by environmental parameters to obtain the thermostat demand opening, obtain the heating demand thermostat opening by the heating status and the thermostat demand opening, and obtain the engine demand thermostat opening according to the heating demand thermostat opening and the engine starting process.

[0039] like Figure 2 As shown, the method for obtaining the basic opening of the engine demand thermostat is to select different calculation methods of the basic opening of the engine demand thermostat according to the state of the basic map selection switch. A cycle is set, and the state of the basic map selection switch of the engine operating parameters, the engine water temperature and the actual engine torque in the cycle are obtained. When the basic map selection switch is in the off state, the basic opening of the engine demand thermostat is calibrated according to the first torque map (MAP1) after filtering based on the engine water temperature and the actual engine torque.

[0040] When the basic map selection switch is in the on state, the engine water temperature change rate is obtained, and the first opening value and the second opening value are obtained by calibrating the engine water temperature and the actual engine torque, wherein the first opening value is calibrated in the second torque map (MAP2), and the second opening value is calibrated in the third torque map (MAP3). When the engine water temperature change rate is less than the preset temperature change rate threshold, the engine demand thermostat basic opening is the first opening value; when the engine water temperature change rate is greater than the temperature change rate threshold, the engine demand thermostat basic opening is the second opening value; when the engine water temperature change rate is equal to the temperature change rate threshold, the engine demand thermostat basic opening is the engine demand thermostat basic opening of the previous cycle, that is, the hysteresis effect, maintaining the value of the previous cycle to keep the system stable.

[0041] like Figure 3 As shown, the method for correcting the basic opening of the engine required thermostat by environmental parameters to obtain the required thermostat opening is to obtain the current position slope, environmental pressure and ambient temperature in the environmental parameters, and calibrate the current position slope and the preset slope-opening curve to obtain the first thermostat opening correction value;

[0042] The second thermostat opening correction value is obtained by calibrating the engine water temperature and the engine water temperature change rate;

[0043] Get the current vehicle speed, and get the third thermostat opening correction value through the current vehicle speed and engine water temperature calibration;

[0044] The fourth thermostat opening correction value is obtained by calibrating the ambient pressure and ambient temperature;

[0045] The engine required thermostat basic opening, the first thermostat opening correction value, the second thermostat opening correction value, the third thermostat opening correction value and the fourth thermostat opening correction value are added together to obtain the required thermostat opening.

[0046] like Figure 4 As shown, the method for obtaining the heater demand thermostat opening through the heater state and the thermostat demand opening is that when the heater state is on, the heater demand thermostat opening is calibrated by the engine water temperature and the preset water temperature-opening curve; when the heater state is off, the heater demand thermostat opening is the thermostat demand opening.

[0047] The heater is turned on and off according to the heater status signal, engine water temperature and ambient temperature. When the heater status signal value is one and the engine water temperature is greater than the preset first water temperature standard value and the ambient temperature is greater than the preset standard temperature, the heater status is judged to be on; otherwise, the heater status is judged to be off.

[0048] like Figure 5As shown, the method for obtaining the engine demand thermostat opening according to the heater demand thermostat opening and the engine start process is:

[0049] The engine running time after starting is obtained during the engine starting process. When the engine running time after starting is less than or equal to the preset running time calibration value and the engine water temperature is greater than or equal to the preset water temperature calibration value, the engine demand thermostat opening is equal to the preset engine demand thermostat opening standard value; otherwise, the engine demand thermostat opening is equal to the heater demand thermostat opening.

[0050] Step 2: Obtain the required retarder thermostat opening according to the engine required thermostat opening, retarder parameters and retarder status. Select different calculation methods for the required retarder thermostat opening through the function selection calibration switch. The required retarder thermostat basic opening is corrected by the engine speed and vehicle gear calibration, and then passes through the Ramp (change by slope) module to obtain the required retarder thermostat opening. The rising rate of change and the falling rate of change of the Ramp module are calibrated by the engine speed and the engine water temperature respectively.

[0051] like Figure 6 As shown in the figure, the calculation method of the first retarder required thermostat opening is:

[0052] The retarder activation state in the retarder state is obtained. When the retarder activation state is a preset first activation state value, the retarder required thermostat opening is equal to the engine required thermostat opening; when the retarder activation state is a preset second activation state value, the retarder temperature, the retarder gear and the retarder actual torque percentage in the retarder parameters are obtained, and the first retarder opening value is obtained by calibrating the retarder temperature and the retarder gear, and the second retarder opening value is calibrated by the retarder actual torque percentage and the preset torque percentage-opening curve, and the first retarder opening value and the second retarder opening value are added to obtain the retarder required thermostat opening; when the retarder activation state is a preset third activation state value, the retarder required thermostat opening is obtained by calibrating the retarder temperature and the retarder actual torque percentage; when the retarder activation state is a preset fourth activation state value, the retarder required thermostat opening is obtained by calibrating the retarder actual torque percentage and the retarder gear.

[0053] In this embodiment, the first activation state value is 0, which indicates that the retarder brake is not activated; the second activation state value is 1; the third activation state value is 2; and the fourth activation state value is 3.

[0054] like Figure 7 As shown in the figure, the second method for calculating the required thermostat opening of the retarder is:

[0055] When the actual retarder torque percentage is less than the preset torque percentage threshold, the retarder required thermostat opening is equal to the engine required thermostat opening; otherwise, the retarder required thermostat opening is obtained by calibrating the retarder temperature and the actual retarder torque percentage.

[0056] The required opening of the electronically controlled thermostat is obtained through the required thermostat opening of the retarder, the working state of the coolant temperature sensor and the working state of the engine.

[0057] The retarder temperature is the retarder water temperature or the retarder oil temperature, and the retarder temperature is selected by a retarder temperature switch.

[0058] Step 3: The method for obtaining the required opening of the electronically controlled thermostat by the required opening of the retarder thermostat, the working state of the coolant temperature sensor and the working state of the engine is:

[0059] When the engine is in shutdown mode, the required opening of the electronically controlled thermostat is the preset default required opening for shutdown of the engine;

[0060] When the engine is in a non-stop state and the coolant temperature sensor is in a faulty state, the required opening of the electronically controlled thermostat is the preset coolant temperature sensor fault default opening;

[0061] When the engine operating state is a non-stop state and the coolant temperature sensor is in a normal working state, the electronically controlled thermostat required opening is the retarder required thermostat opening.

[0062] Step 4: Get the heating duty ratio of the electronically controlled thermostat through the required opening of the electronically controlled thermostat and the engine operating parameters, and control the electronically controlled thermostat through the required opening of the electronically controlled thermostat and the heating duty ratio of the electronically controlled thermostat. This realizes the control of electronically controlled thermostats including electric heating thermostats and electronic thermostats, effectively improving the engine cooling system's ability to regulate the coolant temperature, and improving reliability and economy.

[0063] The method for obtaining the heating duty cycle of the electronically controlled thermostat is to obtain the battery voltage of the whole vehicle and the engine water temperature in the engine operating parameters, calibrate the required heating power of the electronically controlled thermostat by the engine water temperature and the required opening of the electronically controlled thermostat, calibrate the power correction coefficient by the battery voltage of the whole vehicle and a preset voltage-power coefficient curve, multiply the required heating power by the correction coefficient to obtain the required heating correction power, and calibrate the heating duty cycle of the electronically controlled thermostat by the required heating correction power and the preset power-duty cycle curve.

[0064] Select electronic thermostat or electric heating thermostat by the thermostat type selection switch.

[0065] The above is only a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the structure of the present invention, which will not affect the effect of the implementation of the present invention and the practicality of the patent.

Claims

1. A method for controlling an electronically controlled thermostat for a commercial vehicle, characterized in that: The engine required thermostat opening, retarder parameters, retarder status, coolant temperature sensor working status, engine working status and engine operating parameters are obtained; the retarder required thermostat opening is obtained according to the engine required thermostat opening, retarder parameters and retarder status; the electronically controlled thermostat required opening is obtained through the retarder required thermostat opening, coolant temperature sensor working status and engine operating status; the electronically controlled thermostat heating duty cycle is obtained through the electronically controlled thermostat required opening and engine operating parameters; and the electronically controlled thermostat is controlled through the electronically controlled thermostat required opening and the electronically controlled thermostat heating duty cycle.

2. A commercial vehicle electronic thermostat control method according to claim 1, characterized in that: The method for obtaining the engine demand thermostat opening is to obtain the engine demand thermostat basic opening, environmental parameters and heating status, correct the engine demand thermostat basic opening according to the environmental parameters to obtain the thermostat demand opening, obtain the heating demand thermostat opening according to the heating status and the thermostat demand opening, and obtain the engine demand thermostat opening according to the heating demand thermostat opening and the engine starting process.

3. A commercial vehicle electronic thermostat control method according to claim 2, characterized in that: The method for obtaining the basic opening of the engine demand thermostat is to set a cycle, obtain the state of the basic map selection switch of the engine operating parameters, the engine water temperature and the engine actual torque within the cycle, and when the basic map selection switch is in the closed state, calibrate the basic opening of the engine demand thermostat according to the engine water temperature and the engine actual torque; When the basic pulse spectrum selection switch is in the on state, the engine water temperature change rate is obtained, and the first opening value and the second opening value are calibrated by the engine water temperature and the actual engine torque. When the engine water temperature change rate is less than the preset temperature change rate threshold, the engine demand thermostat basic opening is the first opening value; when the engine water temperature change rate is greater than the temperature change rate threshold, the engine demand thermostat basic opening is the second opening value; when the engine water temperature change rate is equal to the temperature change rate threshold, the engine demand thermostat basic opening is the engine demand thermostat basic opening of the previous cycle.

4. A commercial vehicle electronic thermostat control method according to claim 3, characterized in that: The method of correcting the engine required thermostat basic opening by the environmental parameters to obtain the required thermostat opening is to obtain the current position slope, environmental pressure and ambient temperature in the environmental parameters, and calibrate the current position slope and the preset slope-opening curve to obtain the first thermostat opening correction value; The second thermostat opening correction value is obtained by calibrating the engine water temperature and the engine water temperature change rate; Obtaining the current vehicle speed, and obtaining a third thermostat opening correction value by calibrating the current vehicle speed and the engine water temperature; The fourth thermostat opening correction value is obtained by calibrating the ambient pressure and ambient temperature; The engine required thermostat basic opening, the first thermostat opening correction value, the second thermostat opening correction value, the third thermostat opening correction value and the fourth thermostat opening correction value are added together to obtain the required thermostat opening.

5. A commercial vehicle electronic thermostat control method according to claim 4, characterized in that: The method for obtaining the heater demand thermostat opening through the heater state and the thermostat demand opening is that when the heater state is on, the heater demand thermostat opening is calibrated through the engine water temperature and a preset water temperature-opening curve; when the heater state is off, the heater demand thermostat opening is the thermostat demand opening.

6. A commercial vehicle electronic thermostat control method according to claim 5, characterized in that: The method for obtaining the engine demand thermostat opening according to the heating demand thermostat opening and the engine starting process is: Acquiring the engine start-up running time during the engine start-up process, when the engine start-up running time is less than or equal to a preset running time calibration value and the engine water temperature is greater than or equal to a preset water temperature calibration value, the engine demand thermostat opening is equal to a preset engine demand thermostat opening standard value; On the contrary, the engine demand thermostat opening is equal to the heater demand thermostat opening.

7. A commercial vehicle electronic thermostat control method according to claim 1, characterized in that: The method for obtaining the required thermostat opening of the retarder according to the required thermostat opening of the engine, the retarder parameters, and the retarder state includes: Acquiring a retarder activation state in the retarder state, when the retarder activation state is a preset first activation state value, the retarder demand thermostat opening is equal to the engine demand thermostat opening; When the retarder activation state is a preset second activation state value, the retarder temperature, the retarder gear and the actual retarder torque percentage in the parameters of the retarder are obtained, a first retarder opening value is obtained by calibrating the retarder temperature and the retarder gear, a second retarder opening value is calibrated by the actual retarder torque percentage and a preset torque percentage-opening curve, and the first retarder opening value and the second retarder opening value are added to obtain a retarder demand thermostat opening; When the retarder activation state is a preset third activation state value, the retarder required thermostat opening is obtained by calibrating the retarder temperature and the actual torque percentage of the retarder; when the retarder activation state is a preset fourth activation state value, the retarder required thermostat opening is obtained by calibrating the actual torque percentage of the retarder and the retarder gear position.

8. A commercial vehicle electronic thermostat control method according to claim 7, characterized in that: The method for obtaining the required thermostat opening of the retarder according to the required thermostat opening of the engine, the retarder parameters, and the retarder state also includes: When the actual torque percentage of the retarder is less than a preset torque percentage threshold, the retarder required thermostat opening is equal to the engine required thermostat opening; On the contrary, the required thermostat opening of the retarder is obtained by calibrating the retarder temperature and the actual torque percentage of the retarder.

9. A commercial vehicle electronic thermostat control method according to claim 1, characterized in that: The method for obtaining the required opening of the electronically controlled thermostat by using the required opening of the retarder thermostat, the working state of the coolant temperature sensor and the working state of the engine is: When the engine is in shutdown mode, the required opening of the electronically controlled thermostat is a preset default required opening for shutdown of the engine; When the engine is in a non-stop state and the coolant temperature sensor is in a fault state, the required opening of the electronically controlled thermostat is a preset coolant temperature sensor fault default opening; When the engine operating state is a non-shutdown state and the coolant temperature sensor is in a normal working state, the electronically controlled thermostat required opening is the retarder required thermostat opening.

10. A commercial vehicle electronic thermostat control method according to claim 1, characterized in that: The method for obtaining the heating duty cycle of the electronically controlled thermostat is to obtain the battery voltage of the whole vehicle and the engine water temperature in the engine operating parameters, calibrate the required heating power of the electronically controlled thermostat by the engine water temperature and the required opening of the electronically controlled thermostat, calibrate the power correction coefficient by the battery voltage of the whole vehicle and a preset voltage-power coefficient curve, multiply the required heating power by the correction coefficient to obtain the required heating correction power, and calibrate the heating duty cycle of the electronically controlled thermostat by the required heating correction power and the preset power-duty cycle curve.

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