Fire fighting truck chassis based on P3 parallel hybrid power and electric control system thereof

Abstract

The invention discloses a fire fighting truck chassis based on P3 parallel hybrid power and an electric control system thereof.The electric control method comprises the following steps that S10, whether an engine needs to be started or not is judged, if yes, a clutch is closed, the engine is dragged to be started through a driving motor, and then the next step is conducted; if not, enabling the vehicle to enter a pure electric driving working condition and a low-speed driving working condition; s20, judging whether the engine is successfully started or not, if yes, executing the next step, and if not, enabling the vehicle to enter a pure electric driving working condition and a low-speed driving working condition; s30, judging whether the vehicle has a water fetching demand or not, if so, performing the next step, and if not, entering a conventional driving working condition; the acceleration performance of the fire fighting truck is greatly improved, meanwhile, the driving motor can undertake a power output task under part of working conditions, the operation time and load of an engine are reduced, and therefore fuel consumption is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of fire trucks. Specifically, the present invention relates to a fire truck chassis based on P3 parallel hybrid power and its electronic control system. Background Art

[0002] The special chassis for airport fire trucks is used for airport fire fighting and rescue. At present, typical special chassis for airport fire trucks all have one or two large horsepower engines. If one engine is used, a power distributor needs to be installed, and the engine can drive the vehicle and a large power fire pump at the same time; if two engines are used, one of the engines can be used as both a vehicle drive and a fire truck pump drive.

[0003] Limited by its own output characteristics, the engine has poor starting and acceleration performance; for the one-engine drive scheme, the key assembly resource suppliers are relatively single, the cost remains high, which is not conducive to the development of the industry. The engine emissions affect the environment, and the exhaust gas generated when starting in the parking garage needs to be specially treated. The vehicle needs to take power while driving, and it is required that the vehicle can travel at different speeds when the large power pump pumps water at full power. This power take-off method is relatively difficult to achieve and relies on imported components. Summary of the Invention

[0004] The present invention provides a fire truck chassis based on P3 parallel hybrid power and its electronic control system, which solves the problems raised in the above background art.

[0005] To achieve the above object, the technical solution adopted by the present invention is: a fire truck chassis based on P3 parallel hybrid power, including an engine, a clutch, an automatic transmission, a drive motor, a power take-off, a large power pump, a power battery, and a transfer case. The engine is connected to the automatic transmission, and the engine is arranged in parallel with the clutch, the automatic transmission, and the drive motor. The drive motor is electrically connected to the power battery, and the drive motor is connected to the large power pump through the power take-off. The transfer case is used to disconnect and couple the drive motor shaft, the front drive shaft, and the rear drive shaft.

[0006] An electronic control system for a fire truck chassis based on P3 parallel hybrid power includes the following steps: Step S10, determine whether the engine has a starting requirement. If so, make the clutch engage, and start the engine by dragging it with the drive motor, and then proceed to the next step. If not, make the vehicle enter the pure electric driving condition and the low-speed driving condition; Step S20, determine whether the engine starts successfully. If so, proceed to the next step. If not, make the vehicle enter the pure electric driving condition and the low-speed driving condition; Step S30, determine whether the vehicle has a water pumping requirement. If so, proceed to the next step. If not, enter the normal driving condition; Step S40: Determine whether the vehicle is parked to pump water. If so, enter the parked water pumping mode; otherwise, enter the pure electric water pumping mode.

[0007] Preferably, the normal driving mode is divided as follows according to the battery pack SOC: (1) Battery pack SOC < lower limit value: The transfer case is coupled, the clutch is closed, the engine outputs power at high power, the drive motor is in the power generation mode, a part of the engine power is used to drive the vehicle, and the excess power is preferentially used to assist the drive motor to generate power and charge the battery pack. (2) Upper limit value > Battery pack SOC > lower limit value: The transfer case is coupled, the clutch is closed, and the engine and drive motor dispatch the output power at the optimal efficiency point for vehicle drive. (3) Battery pack SOC > upper limit value: The transfer case is coupled, the clutch is disengaged, the drive motor outputs power at high power, consuming the battery power. When the drive motor power is insufficient, the engine works to compensate for the drive motor power.

[0008] Preferably, the parked water pumping mode is divided as follows according to the battery pack SOC: (1) Battery pack SOC < lower limit value: The transfer case is in neutral, the clutch is closed, the engine works at full power to provide power to the high-power water pump, and the drive motor is in the power generation state to charge the battery pack. (2) Upper limit value > Battery pack SOC > lower limit value: The transfer case is in neutral, and the engine and drive motor provide power to the high-power water pump according to the efficiency optimal point. (3) The transfer case is in neutral, the clutch is disengaged, the drive motor provides power to the high-power water pump, and the engine provides power to make up for the insufficient drive motor power.

[0009] Preferably, the pure electric water pumping mode is divided as follows according to the battery pack SOC: (1) Battery pack SOC < lower limit value: The transfer case is coupled, the clutch is closed, the engine works at full power to provide power to the high-power water pump and drive the vehicle. After ensuring the surplus power of the high-power water pump, the drive motor is in the power generation state to charge the battery pack. (2) Upper limit value > Battery pack SOC > lower limit value: The transfer case is coupled, the clutch is closed, and the engine and drive motor provide power to the high-power water pump according to the efficiency optimal point. (3) Battery pack SOC > upper limit value: The transfer case is coupled, the clutch is closed, the drive motor works at full power to provide power to the high-power water pump and drive the vehicle, and the engine provides power to make up for the insufficient drive motor power.

[0010] The beneficial effects of adopting the above technical solutions are: I. Through the unique design of parallel hybrid drive of the engine and the drive motor, due to the characteristic of the drive motor to instantaneously output powerful torque and work in coordination with the engine, the acceleration performance of the fire truck has been greatly improved. At the same time, during daily operation, the drive motor can undertake the power output task under some working conditions, reducing the running time and load of the engine, thereby reducing fuel consumption.

[0011] II. The hybrid drive of the engine and the drive motor endows the chassis with strong fault tolerance. When the drive motor fails, the engine can independently take on the heavy responsibility of driving the vehicle, ensuring that the fire truck can still drive normally to a safe area or a repair location; conversely, if the engine fails, the drive motor can also take over in time to maintain the basic operation of the vehicle.

[0012] III. Through reasonable power distribution and control strategies, the fire truck in this solution has successfully achieved efficient power take-off under different water spraying conditions. This solution can intelligently adjust the power output of the engine and the drive motor according to the water spraying power demand and the vehicle driving speed, ensuring that sufficient and stable power can be provided for the water pump under various working conditions. Whether it is in the working condition of low-speed large-flow water spraying or high-speed small-flow water spraying, efficient power take-off can be achieved to meet the actual needs of fire fighting operations.

[0013] IV. In some places with high air quality requirements, such as enclosed spaces like parking garages, the exhaust gas emitted by the engine of traditional fire trucks will quickly accumulate, causing serious impacts on human health and the environment. However, the fire truck in this solution can switch to the pure electric drive mode under these working conditions, completely eliminating engine emissions and significantly reducing environmental pollution.

[0014] V. When the SOC of the battery pack is relatively high and the power demand of the working condition is relatively small, the vehicle preferentially adopts the pure electric drive mode, making full use of the electric energy stored in the battery, reducing unnecessary starts and operations of the engine, thereby reducing fuel consumption; when the SOC of the battery pack is relatively low or the power demand of the working condition is relatively large, the engine and the drive motor work in coordination, reasonably distributing power according to the actual demand, ensuring that while meeting the power demand of the vehicle, the energy utilization efficiency is maximized. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is the system block diagram provided by the present invention; Figure 2 is the energy transmission block diagram provided by the present invention; Figure 3 is the logic flow chart provided by the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0016] The specific implementation methods of the present invention are further explained in detail below by describing the embodiments with reference to the accompanying drawings, with the aim of helping those skilled in the art to have a more complete, accurate and in-depth understanding of the concept and technical solution of the present invention and facilitating its implementation. Example 1

[0017] Specifically, Figure 1 and Figure 2 As shown, a fire truck chassis based on P3 parallel hybrid power includes an engine, a clutch, an automatic transmission, a drive motor, a power take-off, a high-power water pump, a power battery and a transfer case. The engine is connected to the automatic transmission, and the engine is arranged in parallel with the clutch, the automatic transmission and the drive motor. The drive motor is electrically connected to the power battery, and the drive motor is connected to the high-power water pump through the power take-off. The transfer case is used to disconnect the coupling drive motor shaft, the transmission front axle, and the transmission rear axle.

[0018] It should be noted that the engine is connected to the automatic transmission, which ensures that the power of the engine can be effectively transmitted to the automatic transmission to realize the vehicle's speed shifting function; at the same time, the engine is connected in parallel with the clutch, automatic transmission and drive motor, providing the vehicle with a variety of power output modes and flexible driving strategies; the drive motor is electrically connected to the power battery, and the power battery provides power support for the drive motor, so that the drive motor can independently drive the vehicle or assist the engine in working; In addition, the drive motor is connected to the high-power water pump through a power take-off. When fire-fighting water pumping operations are required, the drive motor can transfer power to the high-power water pump through the power take-off to realize the operation of the water pump; the transfer case is used to disconnect the coupling drive motor shaft, the transmission front axle, and the transmission rear axle. Through the operation of the transfer case, the power distribution path can be flexibly controlled to meet the driving needs of the vehicle under different working conditions. For example, in the four-wheel drive escape condition, the transfer case can couple the front axle and the rear axle to enable the vehicle to achieve four-wheel drive. Example 2

[0019] like Figure 3 As shown, an electronic control system for a fire truck chassis based on a P3 parallel hybrid power system includes the following steps: Step S10, determining whether the engine needs to be started, if yes, engaging the clutch, and driving the engine by the drive motor to start, and then proceeding to the next step, if no, the vehicle enters a pure electric driving condition and a low-speed driving condition; It should be noted that the above judgment is usually based on factors such as the vehicle's start command or the current vehicle state; the drive motor can effectively drive the engine to start with its good starting torque characteristics, solving the problem of poor starting acceleration performance of the engine itself; For example, when the vehicle only needs to move at a low speed in a garage, it can directly use pure electric drive to achieve zero emissions and quiet operation.

[0020] Step S20, determining whether the engine is started successfully, if yes, proceeding to the next step, if no, the vehicle enters a pure electric driving condition and a low-speed driving condition; It should be noted that the above judgment is determined by detecting parameters such as the engine speed and oil pressure.

[0021] Step S30, determining whether the vehicle needs to pump water, if yes, proceed to the next step, if no, enter the normal driving condition; It should be noted that the above judgment is based on the instructions of the firefighting operation or the information detected by relevant sensors.

[0022] Step S40, determining whether the vehicle is stopped for water pumping, if so, entering the stopped water pumping condition, if not, entering the pure electric water pumping condition.

[0023] It should be noted that in addition to the ascending condition, the following conditions are also included: In the four-wheel drive escape condition, when the rear wheels of the vehicle are stuck, the driver triggers the four-wheel drive mode, the transfer case synchronously couples the front and rear axle drive shafts, the drive motor and the engine power are combined and distributed to the four wheels, the VCU limits the output torque to avoid overloading the transmission system, and automatically switches to the two-wheel drive mode after the vehicle escapes from the jam; In the parking power generation condition, when the vehicle is parked and the SOC is <15%, the driver starts the power generation mode, the clutch is engaged, the engine operates at an economic speed of 1800rpm (output 200kW), the drive motor switches to the power generation mode, and 180kW of electricity is stored in the power battery. It automatically shuts down when the SOC is charged to 80%.

[0024] The conventional driving conditions are divided into the following cases according to the battery pack SOC: (1) Battery pack SOC < lower limit: the transfer case is coupled, the clutch is closed, the engine is outputting high power, the drive motor is in power generation mode, part of the engine power is used to drive the vehicle, and priority is given to ensuring that the excess power is used to assist the drive motor in generating electricity to charge the battery pack; (2) Upper limit value > battery pack SOC > lower limit value: the transfer case is coupled, the clutch is closed, and the engine and drive motor are scheduled to output power at the optimal efficiency point for vehicle driving; (3) Battery pack SOC>upper limit value: the transfer case is coupled, the clutch is disconnected, the drive motor outputs high power, and consumes battery power. If the drive motor power is insufficient, the engine works to compensate for the drive motor power.

[0025] The parking water pumping condition is divided into the following cases according to the battery pack SOC: (1)When the SOC of the battery pack is less than the lower limit: the transfer case is in neutral, the clutch is engaged, the engine operates at full power to provide power for the high-power water pump, and the drive motor is in the power generation state to charge the battery pack; (2)When the upper limit > the SOC of the battery pack > the lower limit: the transfer case is in neutral, and the engine and the drive motor provide power for the high-power water pump according to the most efficient point; (3)The transfer case is in neutral, the clutch is disengaged, the drive motor provides power for the high-power water pump, and the engine provides power to make up for the insufficient power of the drive motor.

[0026] The pure electric water pumping condition is divided into the following situations according to the SOC of the battery pack: (1)When the SOC of the battery pack is less than the lower limit: the transfer case is coupled, the clutch is engaged, the engine operates at full power to provide power for the high-power water pump and drive the vehicle, and after ensuring that the power of the high-power water pump is sufficient, the drive motor is in the power generation state to charge the battery pack; (2)When the upper limit > the SOC of the battery pack > the lower limit: the transfer case is coupled, the clutch is engaged, and the engine and the drive motor provide power for the high-power water pump according to the most efficient point; (3)When the SOC of the battery pack is greater than the upper limit: the transfer case is coupled, the clutch is engaged, the drive motor operates at full power to provide power for the high-power water pump and drive the vehicle, and the engine provides power to make up for the insufficient power of the drive motor.

[0027] For example, the parameters of a certain airport fire truck are as follows: Engine: 550 hp, drive motor: 350 kW, power battery: 300 kWh, water pump: 250 kW Driving and water pumping scenario (SOC = 50%): 1. The VCU detects the water pumping demand & the vehicle speed > 0 → enter the driving and water pumping condition; 2. When the SOC is between the lower limit (30%) and the upper limit (70%) → the transfer case is coupled + the clutch is engaged; 3. The engine outputs 400 kW (250 kW for the water pump and 150 kW for driving the vehicle); 4. The drive motor outputs 150 kW to assist in vehicle driving.

[0028] The above has made an exemplary description of the present invention in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited by the above methods. As long as various non-substantive improvements are made by adopting the method concept and technical solution of the present invention; or without improvement, the above concept and technical solution of the present invention are directly applied to other occasions, they are all within the protection scope of the present invention.

Claims

1. A fire truck chassis based on P3 parallel hybrid power, characterized in that, It includes an engine, a clutch, an automatic transmission, a drive motor, a power take-off, a high-power water pump, a power battery, and a transfer case. The engine is connected to the automatic transmission, and the engine is arranged in parallel with the clutch, the automatic transmission, and the drive motor. The drive motor is electrically connected to the power battery. The drive motor is connected to the high-power water pump through the power take-off. The transfer case is used to disconnect and couple the drive motor shaft, the front drive shaft, and the rear drive shaft.

2. The electronic control system of a fire truck chassis based on P3 parallel hybrid power according to claim 1, characterized in that, It includes the following steps: Step S10: Determine whether the engine has a starting requirement. If so, engage the clutch and start the engine by dragging it with the drive motor, and then proceed to the next step. If not, make the vehicle enter the pure electric driving mode and the low-speed driving mode; Step S20: Determine whether the engine has started successfully. If so, proceed to the next step. If not, make the vehicle enter the pure electric driving mode and the low-speed driving mode; Step S30: Determine whether the vehicle has a water pumping requirement. If so, proceed to the next step. If not, enter the normal driving mode; Step S40: Determine whether the vehicle stops to pump water. If so, enter the parking water pumping mode. If not, enter the pure electric water pumping mode.

3. The electronic control system of a fire truck chassis based on P3 parallel hybrid power according to claim 2, characterized in that, The normal driving mode is divided into the following situations according to the battery pack SOC: (1) Battery pack SOC < lower limit value: The transfer case is coupled, the clutch is closed, the engine outputs high power, the drive motor is in the power generation mode, a part of the engine power is used to drive the vehicle, and the excess power is preferentially used to assist the drive motor to generate power and charge the battery pack; (2) Upper limit value > battery pack SOC > lower limit value: The transfer case is coupled, the clutch is closed, and the engine and the drive motor schedule the power output at the optimal efficiency point for vehicle drive; (3) Battery pack SOC > upper limit value: The transfer case is coupled, the clutch is disconnected, the drive motor outputs high power, consuming the battery power. When the drive motor power is insufficient, the engine works to compensate for the drive motor power.

4. The electronic control system of a fire truck chassis based on P3 parallel hybrid power according to claim 2, characterized in that, The parking water pumping mode is divided into the following situations according to the battery pack SOC: Battery pack SOC < lower limit value: The transfer case is in neutral, the clutch is closed, the engine works at full power to provide power for the high-power water pump, and the drive motor is in the power generation state to supplement the battery pack; Upper limit value > battery pack SOC > lower limit value: The transfer case is in neutral, and the engine and the drive motor provide power for the high-power water pump according to the efficiency optimal point; The transfer case is in neutral, the clutch is disconnected, the drive motor provides power for the high-power water pump, and the engine provides power to make up for the insufficient drive motor power.

5. The electronic control system of a fire truck chassis based on P3 parallel hybrid power according to claim 2, wherein The pure electric water pumping mode is divided into the following situations according to the battery pack SOC: Battery pack SOC < lower limit value: The transfer case is coupled, the clutch is closed, the engine works at full power to provide power for the high-power water pump and drive, and after ensuring that the power of the high-power water pump is sufficient, the drive motor is in the power generation state to supplement the battery pack; Upper limit value > battery pack SOC > lower limit value: The transfer case is coupled, the clutch is closed, and the engine and the drive motor provide power for the high-power water pump according to the efficiency optimal point; Battery pack SOC > upper limit value: The transfer case is coupled, the clutch is closed, the drive motor works at full power to provide power for the high-power water pump and drive, and the engine provides power to make up for the insufficient drive motor power.

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