Commercial vehicle distributed active air inlet grille and control method thereof

Abstract

The invention discloses a commercial vehicle distributed active air inlet grille which comprises a base, a plurality of sets of sub-grilles are distributed on the air inlet end face of the base and used for conducting heat dissipation on an automobile air conditioner system, an engine heat management system and a transmission heat management system respectively, and the multiple sets of sub-grilles achieve cooperative movement or independent movement through a control system; compared with the prior art, a whole grille with a large area is divided into a plurality of sub-grilles with small areas, and a plurality of AGS actuators are used for controlling the corresponding sub-grilles respectively, so that the load of a single actuator is reduced, normal work of an AGS system of the commercial vehicle is ensured, and meanwhile, the danger brought to the commercial vehicle due to the fault of the single AGS actuator is also greatly reduced; in addition, the invention discloses a control method, independent control of the distributed AGS sub-grids can be achieved, independent movement and coordinated movement can be achieved, and the control method is more flexible when applied to the AGS. And the method is not limited to commercial vehicle types, and is suitable for a multi-grid system.

Description

Technical Field

[0001] The present invention belongs to the field of commercial vehicle air intake grilles, and in particular to a commercial vehicle distributed active air intake grille and a control method thereof. Background Art

[0002] The Active Grille Shutter (AGS) technology can achieve significant fuel-saving effects at a relatively low cost. It was first used in high-end passenger cars in the European and American markets, and later attracted the attention of domestic OEMs and began to be used. Now AGS has become a relatively mature technology in passenger cars and is being introduced into the commercial vehicle field.

[0003] The AGS of passenger cars is not large in size, and one actuator and one grille can meet the use requirements. The reference technology is: Announcement No. CN216833207U discloses an automotive active air intake grille assembly. However, for commercial vehicles, the air intake area of ​​the vehicle body is larger and the driving conditions are more severe. It is sometimes difficult to drive all the grille blades with only one actuator. At this time, the AGS actuator is easily burned due to the load reaching the limit. In extreme cases, it may damage the thermal management system of the commercial vehicle, bringing danger to the vehicle. Summary of the invention

[0004] The present invention proposes a distributed active air intake grille for commercial vehicles and a control method thereof, which effectively reduces the load of the original single actuator and also greatly reduces the risk to the commercial vehicle caused by the failure of a single actuator.

[0005] In order to solve the above technical problems, the technical solution of the present invention is: a distributed active air intake grille for commercial vehicles, including a base, characterized in that: a plurality of windows are distributed on the air inlet end surface of the base, a sub-grille is provided in each window, and the plurality of sets of sub-grilles are respectively used for dissipating heat for the automobile air-conditioning system, the engine thermal management system and the transmission thermal management system, and the plurality of sets of sub-grilles can realize coordinated movement or independent movement through a control system.

[0006] The above technical solution is further limited in that the condenser in the automobile air-conditioning system dissipates heat through the corresponding sub-grid.

[0007] The above technical solution is further limited in that the cooling water tank in the engine thermal management system dissipates heat through the corresponding sub-grid.

[0008] The above technical solution is further limited in that the transmission oil cooler in the transmission thermal management system dissipates heat through corresponding sub-grids.

[0009] The above technical solution is further limited in that the control system is mainly composed of sensors, an OBD vehicle automatic diagnosis system and a BCM body control module.

[0010] The above technical solution is further improved in that an air-conditioning air-inlet pressure regulator is provided on the air-inlet end face of the base, and the air-conditioning air-inlet pressure regulator can realize independent movement or coordinated movement with the sub-grill through a control system.

[0011] The control method of the distributed active air intake grille of a commercial vehicle is as follows: various heat dissipation components on the vehicle body are preset with corresponding temperature thresholds, and real-time temperature status parameters can be detected by sensors and published on the OBD system bus; when the temperature status parameters are within the set threshold range, the BCM determines that the vehicle is in a normal working condition, and multiple sets of sub-grilles perform coordinated movement; if the temperature status parameters of a certain component or multiple components exceed the set threshold, the BCM determines that the corresponding components are in a dangerous working condition, and the multiple sets of sub-grilles move independently.

[0012] The above technical solution is further limited in that the sub-grilles realize coordinated movement based on a comparison table of vehicle speed and sub-grille blade angles, and the sub-grille angles are adjusted according to the vehicle speed.

[0013] The above technical solution is further defined, and the calculation process of the independent movement of the sub-grille is as follows: 1) Current heat generation: Q1 = C1*M*ΔT1; C1 is the specific heat capacity of the coolant, M is the mass of the coolant in the cooling water tank, ΔT1 is the difference between the current temperature of the heat dissipation component and the set temperature threshold, and Q1 is the heat generation; 2) Inlet heat dissipation: Q2 = C2*S*v*ρ*t*ΔT2; C2 is the specific heat capacity of the air, S is the air intake area required by the sub-grille, and v is the current vehicle speed ( = (i.e., air flow velocity), ρ is air density, Q2 is calorific value, t is cooling time, ΔT2 is the difference between ambient temperature and temperature threshold; in the above formula, if the required cooling time t is preset as a fixed value, only S is unknown, and the others are known quantities (constants or measurable data), let Q1 = Q2, calculate the air intake area S required by the active air intake grille, measure the air intake area when the active air intake grille is fully opened, and calculate it as A, then the grille target angle can be calculated using the following formula: Since the maximum opening angle of the grille is 90°, if the calculated S>A, then let S=A and substitute it into the above formula for calculation.

[0014] The above technical solution is further improved, and the air conditioning inlet pressure status parameters are published in real time on the OBD system bus; when the pressure status parameters are within the set threshold range, the BCM determines that the entire vehicle is in a normal operating condition, and the air conditioning inlet pressure regulator and the heat dissipation sub-grille perform coordinated movement; if the air conditioning pressure status parameters exceed the set threshold, the BCM determines that the corresponding components are in a dangerous condition, and the air conditioning inlet pressure regulator moves independently.

[0015] To further limit the above technical solution, the air conditioner inlet pressure calculation process is as follows: 1) Record the air conditioner inlet pressure threshold F and the actual inlet pressure: C d is the drag coefficient, which can be measured by experiment (considered known); ρ is the air density, v is the vehicle speed (air velocity), S is the air intake area, let F = Fw, solve S, and the required air intake area can be obtained; 2) Measure the air intake area when the sub-grille is fully open, counted as A, then the sub-grille target angle can be calculated using the following formula: Since the maximum opening angle of the grille is 90°, if the calculated S>A, then let S=A and substitute it into the above formula for calculation.

[0016] Beneficial effects: Compared with the prior art, the present invention divides a whole grille with a larger area into multiple sub-grilles with smaller areas, and uses multiple AGS actuators to control the corresponding sub-grilles respectively, so as to reduce the load of a single actuator and ensure the normal operation of the AGS system of commercial vehicles. At the same time, it also greatly reduces the danger to commercial vehicles caused by the failure of a single AGS actuator; in addition, the present invention provides a control method that can realize independent control of distributed AGS sub-grilles, which can move individually or in a coordinated manner, and is more flexible in AGS applications; and the method is not limited to commercial vehicle models, but is applicable to multi-grille systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is the structural diagram of the distributed air intake grille of a commercial vehicle.

[0018] Figure 2 This is the communication architecture diagram of the distributed air intake grille of a commercial vehicle.

[0019] Figure 3 It is a control flow chart of the distributed active air intake grille of commercial vehicles.

[0020] Figure 4 It is a comparison table between vehicle speed and sub-grille blade turning angle. DETAILED DESCRIPTION

[0021] like Figure 1 As shown, the distributed active air intake grille for commercial vehicles comprises a base 1, and windows of various sizes are distributed on the air intake end face of the base, and sub-grates are arranged in each window, and there are three sets of sub-grates in total. The first set of sub-grates 2 is used to dissipate heat for the condenser in the automobile air-conditioning system, the second set of sub-grates 3 is used to dissipate heat for the cooling water tank in the engine thermal management system, and the third set of grilles 4 is used to dissipate heat for the transmission oil cooler in the transmission thermal management system; an air-conditioning air intake pressure regulator 5 is arranged on the air intake end face of the base, and the air-conditioning air intake pressure regulator is used to improve the air intake pressure of the air-conditioning system, avoid damage to the air compressor, and help to extend the service life;

[0022] The first set of sub-grilles, the second set of sub-grilles, the third set of grilles and the air-conditioning inlet pressure regulator have the same structure as the automobile active air intake grille; the automobile active air intake grille includes a grille mechanical structure body and an actuator; the actuator includes an MCU and a motor, wherein the MCU includes a communication module, a control module and a drive module; the reference technology of the automobile active air intake grille is: Announcement No. CN216833207U discloses an automobile active air intake grille assembly, and the grille plate disclosed in the technology is the grille blade.

[0023] The first set of sub-grilles, the second set of sub-grilles, the third set of sub-grilles and the air-conditioning inlet pressure regulator realize coordinated movement or independent movement through a control system; the control system is mainly composed of sensors, an OBD vehicle-mounted automatic diagnostic system and a BCM body control module;

[0024] The sensors are divided into temperature sensors and pressure sensors; the temperature sensors are arranged on the condenser, cooling water tank and transmission oil cooler, and the pressure sensor is arranged at the air inlet of the automobile air conditioning system.

[0025] like Figure 2 As shown in the figure, the communication architecture diagram of the distributed air intake grille of a commercial vehicle: BCM sends a set of AGS action angle signal request messages through bus 6, and the grille actuator MCU of the first set of sub-grille 2, the second set of sub-grille 3, the third set of sub-grille 4 and the air conditioning inlet pressure regulator 5 can receive the corresponding messages and process them into angle information, and calculate and output the corresponding PWM signal through BCM to control the operation of the motor, thereby driving the grille to rotate to the target angle to realize the opening or closing control of AGS. In the bus communication system, each node has a unique address; if a sub-grille needs to move, only one angle control message corresponding to the node address is sent; if several sub-grilles need to move in coordination, a group of control messages with the same angle can be sent at the same time, and each control message needs to correspond to the corresponding sub-grille node address. There is no specific restriction on the type of communication bus in this technology, which can be a CAN bus or a LIN bus, etc., which should be determined by the communication protocol supported by the MCU of the AGS actuator. Generally, the number of sub-grilles of the distributed active air intake grille of commercial vehicles is usually not too large, and the efficiency of bus-based control is also relatively high.

[0026] like Figure 3As shown, the control method of the distributed active air intake grille of a commercial vehicle is as follows: various heat dissipation components on the vehicle body are preset with corresponding temperature thresholds, and the real-time temperature state parameters can be detected by sensors and published on the OBD system bus; when the temperature state parameters are within the set threshold range, the BCM determines that the vehicle is in a normal working condition, and multiple sets of sub-grates perform coordinated movement; if the temperature state parameters of a certain component or multiple components exceed the set threshold, the BCM determines that the corresponding components are in a dangerous working condition, and the multiple sets of sub-grates move independently;

[0027] Further explanation of the BCM's judgment of coordinated movement: the sub-grille coordinated movement means that the blade angles of multiple sub-grilles are the same; when the temperature state parameter is within the set threshold range, the wind resistance optimization of the whole vehicle takes a dominant position, and the sub-grille opening is controlled with the optimization of wind resistance as the main purpose, and the core influencing factor is the vehicle speed; Figure 4 As shown, according to the comparison table of vehicle speed and sub-grille blade angle, the sub-grille angle is adjusted according to the vehicle speed; in the coordinated motion state, the wind resistance of the whole vehicle increases with the increase of vehicle speed; when the commercial vehicle is under heavy load and low speed, the vehicle speed has little effect on the wind resistance, and the grille opening can be increased to dissipate heat as much as possible (the heat generated by the driving components is also large under low speed and heavy load); when the commercial vehicle is under light load and high speed, the vehicle speed has a greater impact on the wind resistance, and the grille opening needs to be reduced to reduce the wind resistance of the whole vehicle and achieve fuel saving; in addition, when the ambient temperature is too low, in order to warm up the engine as soon as possible, all grilles need to be closed; in this technology, the temperature for cold vehicle start-up is set to be when the ambient temperature is lower than -10℃, at which time all sub-grilles of the vehicle need to be closed, and the temperature determination takes precedence over the vehicle speed determination;

[0028] Further explanation of BCM's independent motion determination: Taking the engine cooling water tank as an example, the calculation process of the corresponding sub-grille independent motion is as follows: 1) Current heat generation: Q1 = C1*M*ΔT1; C1 is the specific heat capacity of the coolant, M is the mass of the coolant in the cooling water tank, ΔT1 is the difference between the current temperature of the heat dissipation component and the set temperature threshold, and Q1 is the heat generation; 2) Inlet heat dissipation: Q2 = C2*S*v*ρ*t*ΔT2; C2 is the specific heat capacity of the air, S is the air inlet area required by the sub-grille Product, v is the current vehicle speed (i.e., air flow speed), ρ is the air density, Q2 is the calorific value, t is the cooling time, and ΔT2 is the difference between the ambient temperature and the temperature threshold; in the above formula, if the required cooling time t is set in advance as a fixed value, then only S is unknown, and the others are known quantities (constants or measurable data). Let Q1=Q2, calculate the air intake area S required by the active air intake grille, measure the air intake area when the active air intake grille is fully opened, and calculate it as A, then the grille target angle can be calculated using the following formula: Since the maximum opening angle of the grille is 90°, if the calculated S>A, then let S=A and substitute it into the above formula for calculation; the above idea can be used to derive the heat dissipation components on the car body (core idea: heat generation = heat dissipation) to realize the calculation of the sub-grille angle;

[0029] The OBD system bus publishes the air-conditioning air inlet pressure state parameters in real time; when the pressure state parameters are within the set threshold range, the BCM determines that the vehicle is in normal working condition, and the air-conditioning air inlet pressure regulator and the heat dissipation sub-grill perform coordinated movement; if the pressure state parameters exceed the set threshold, the BCM determines that the corresponding components are in a dangerous working condition, and the air-conditioning air inlet pressure regulator moves independently; the air-conditioning air inlet pressure calculation process is as follows: 1) record the air-conditioning air inlet pressure threshold F, actual air inlet pressure: C d is the drag coefficient, which can be measured by experiment (considered known); ρ is the air density, v is the vehicle speed (air velocity), S is the air intake area, let F = Fw, solve S, and the required air intake area can be obtained; 2) Measure the air intake area when the sub-grille is fully open, counted as A, then the sub-grille target angle can be calculated using the following formula: Since the maximum opening angle of the grille is 90°, if the calculated S>A, then let S=A and substitute it into the above formula for calculation.

[0030] The effects of the described method for calculating the independent movement of the sub-grouts and the air-conditioning inlet pressure are as follows: through rigorous and accurate theoretical derivation, an equation related to the required air inlet area S is established, the required air inlet area is accurately calculated, and then the grille opening value is obtained through proportional conversion. Such a calculation method has high control accuracy for a single grille, laying the foundation for AGS to achieve excellent control effects; the calculation method focuses on the core factors that affect the performance of AGS in the corresponding situation and ignores non-critical factors with less impact, making the calculation form simpler and easy to program in the algorithm, and consuming less computing power resources for the controller, so that the response time of the actuator can be effectively shortened during the execution of AGS, greatly improving the control efficiency and accuracy.

Claims

1. A distributed active air intake grille for a commercial vehicle, including a base, characterized in that: There are multiple windows distributed on the air inlet end face of the base, each window is equipped with a sub-grille, and the multiple sets of sub-grilles are used to dissipate heat for the automobile air-conditioning system, engine thermal management system and transmission thermal management system respectively. The multiple sets of sub-grilles can achieve coordinated movement or independent movement through the control system.

2. The distributed active air intake grille for commercial vehicles according to claim 1, characterized in that: The condenser in the automobile air-conditioning system achieves heat dissipation through the corresponding sub-grille; the cooling water tank in the engine thermal management system achieves heat dissipation through the corresponding sub-grille; the transmission oil cooler in the transmission thermal management system achieves heat dissipation through the corresponding sub-grille.

3. The distributed active air intake grille for commercial vehicles according to claim 1 or 2, characterized in that: The control system is mainly composed of sensors, OBD vehicle automatic diagnosis system and BCM body control module.

4. The distributed active air intake grille for commercial vehicles according to claim 3, characterized in that: An air-inlet pressure regulator for air conditioning is arranged on the air-inlet end surface of the base, and the air-inlet pressure regulator for air conditioning can realize independent movement or coordinated movement with the sub-grid through a control system.

5. A method for controlling a distributed active air intake grille for commercial vehicles is as follows: various heat dissipation components on the vehicle body are preset with corresponding temperature thresholds, and real-time temperature status parameters can be detected by sensors and published on the OBD system bus; when the temperature status parameters are within the set threshold range, the BCM determines that the vehicle is in a normal working condition, and multiple sets of sub-grilles perform coordinated movement; if the temperature status parameters of a component or multiple components exceed the set threshold, the BCM determines that the corresponding components are in a dangerous working condition, and the multiple sets of sub-grilles move independently.

6. The commercial vehicle distributed active air intake grille control method according to claim 5, characterized in that: The calculation process of the independent movement of the sub-grille is as follows: 1) Current heat generation: Q1 = C1*M*ΔT1; C1 is the specific heat capacity of the coolant, M is the mass of the coolant in the cooling water tank, ΔT1 is the difference between the current temperature of the heat dissipation component and the set temperature threshold, and Q1 is the heat generation; 2) Air intake heat dissipation: Q2 = C2*S*v*ρ*t*ΔT2; C2 is the specific heat capacity of the air, S is the air intake area required by the sub-grille, v is the current vehicle speed, ρ is the air density, Q2 is the heat generation, t is the cooling time, and ΔT2 is the difference between the ambient temperature and the temperature threshold; in the above formula, if the required cooling time t is set in advance as a fixed value, then only S is unknown, and the others are all known quantities. Let Q1 = Q2, calculate the air intake area S required by the active air intake grille, measure the air intake area when the active air intake grille is fully open, and calculate it as A, then the grille target angle can be calculated using the following formula: Since the maximum opening angle of the grille is 90°, if the calculated S>A, then let S=A and substitute it into the above formula for calculation.

7. The method for controlling a distributed active air intake grille of a commercial vehicle according to claim 5 or 6, characterized in that: The OBD system bus publishes the air conditioning inlet pressure status parameters in real time; when the pressure status parameters are within the set threshold range, the BCM determines that the vehicle is in a normal working condition, and the air conditioning inlet pressure regulator and the heat dissipation sub-grille perform coordinated movement; if the air conditioning pressure status parameters exceed the set threshold, the BCM determines that the corresponding component is in a dangerous working condition, and the air conditioning inlet pressure regulator moves independently.

8. The commercial vehicle distributed active air intake grille control method according to claim 7, characterized in that: The air conditioner inlet pressure calculation process is as follows: 1) Record the air conditioner inlet pressure threshold F and the actual inlet pressure: C d is the drag coefficient, which can be measured by experiment; ρ is the air density, v is the vehicle speed, S is the air intake area, let F = Fw, solve S, and you can get the required air intake area; 2) Measure the air intake area when the sub-grille is fully open, counted as A, then the sub-grille target angle can be calculated using the following formula: Since the maximum opening angle of the grille is 90°, if the calculated S>A, then let S=A and substitute it into the above formula for calculation.

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