A vehicle air conditioning control system

Abstract

The application discloses a kind of vehicle air conditioner control systems, including control panel, MCU, ADC detection module, actuator module, power module, backlight lamp adjusting module, CAN communication module and spare drive circuit.Control panel adopts matrix key to receive instruction;MCU processes signal and exports control instruction;ADC detection module monitors car machine state, power supply and temperature signal;Actuator module realizes air door adjustment and air speed control by drive circuit;Power module provides stable power supply and has multiple protection;Backlight lamp adjusting module adjusts brightness by PWM signal;CAN module realizes and vehicle body network communication;Spare drive circuit supports external equipment extension.The system control precision is high, interactive friendly, strong expansibility, stable operation, can improve driving comfort and system reliability.

Description

Technical Field

[0001] This utility model relates to the field of air conditioning control technology, and in particular to a vehicle air conditioning control system. Background Technology

[0002] With the development of the automotive industry, vehicle air conditioning systems have become one of the core components for improving driving comfort, and their performance directly affects user experience and vehicle energy consumption. Existing vehicle air conditioning control systems have the following shortcomings: First, limited control precision, large temperature regulation errors, and insufficient precision in damper opening and airflow control, leading to significant fluctuations in cabin temperature; second, poor system scalability, making it difficult to be compatible with external expansion devices and limiting functional upgrades; and third, weak status detection and fault diagnosis capabilities, failing to monitor actuator operating status and power supply stability in real time, making it difficult to quickly locate problems after a fault occurs.

[0003] Therefore, this utility model provides a new solution to this problem. Utility Model Content

[0004] In view of the above situation and to overcome the defects of the prior art, the purpose of this utility model is to provide a vehicle air conditioning control system.

[0005] The technical solution is: a vehicle air conditioning control system, comprising:

[0006] The control panel features an AUTO button, a front defogger button, an airflow adjustment button, an AC button, a mode adjustment button, a rear defogger button, an internal / external circulation button, an OFF button, and a temperature adjustment button. It is used to receive user operation commands and transmit them to the MCU.

[0007] The MCU is connected to the control panel and configured to process input signals and output control commands.

[0008] The ADC detection module is connected to the MCU and is used to detect the vehicle status signal, power supply status signal, and cabin temperature signals.

[0009] The actuator module includes a blower, a hot and cold air damper actuator, a mode damper actuator, and a fresh air damper actuator. The actuator module is connected to an actuator drive circuit, which receives control commands from the MCU and drives the actuators to operate.

[0010] The power module provides +5V and +12V power to all modules in the system.

[0011] A backlight adjustment module, connected to the MCU, is used to adjust the backlight brightness of the control panel's display screen and buttons;

[0012] The CAN communication module is connected to the MCU to enable message interaction between the system and the vehicle network.

[0013] Optionally, the control panel adopts a 3*4 matrix key circuit. This circuit is connected to the input pins of the BU91600FUV-ME2 chip through 3 row lines and 4 column lines. Each key is connected to the intersection of the row line and the column line. The BU91600FUV-ME2 chip scans the changes in the column line level row by row through its built-in logic circuit, identifies the key operation and parses it into user instructions, and then transmits the instructions to the MCU through the SPI interface.

[0014] Optionally, the MCU uses a GD32A503Cx chip. The MCU is connected to the control panel, ADC detection module, actuator module, backlight adjustment module and CAN communication module through multiple I / O interfaces, and is configured with an SWD program update interface to realize program updates and debugging.

[0015] Optionally, the actuator drive circuit includes a stepper motor drive circuit and a blower drive circuit;

[0016] The stepper motor drive circuit is used to drive the stepping action of the heating and cooling damper actuator, the mode damper actuator, and the fresh air damper actuator to adjust the damper opening.

[0017] The blower drive circuit is used to control the wind speed adjustment of the blower.

[0018] Optionally, the stepper motor drive circuit includes multiple load drivers. The input terminal of the load driver is connected to the MCU, and the output terminal of the load driver is connected to the coil windings of the heating / cooling damper actuator, the mode damper actuator, and the fresh air damper actuator, respectively. By controlling the energizing sequence and current magnitude of each phase winding, the corresponding stepper motor is driven to achieve angle adjustment and position control.

[0019] Optionally, the blower drive circuit includes a first amplifier and a second amplifier;

[0020] The non-inverting input of the first amplifier is connected to the blower's power supply voltage, and the inverting input is connected to the blower's feedback terminal. This is used to calculate the blower's operating voltage and perform a proportional reduction. Its output is connected to the inverting input of the second amplifier.

[0021] The non-inverting input of the second amplifier is connected to the PWM control output of the MCU through an RC filter circuit to convert the PWM control signal into a smooth DC control voltage. The second amplifier compares the DC control voltage at the non-inverting input with the blower operating voltage signal at the inverting input and outputs a corresponding level signal to control the working state of the blower.

[0022] Optionally, the ADC detection module includes:

[0023] The vehicle status detection unit is used to detect the phase feedback signals and fault diagnosis incremental signals of the blower, heating and cooling damper actuator, mode damper actuator and fresh air damper actuator, so as to monitor the operating status and fault information of each actuator.

[0024] The power supply status detection unit is used to detect the actuator reset power signal RES_Power and the +5V and +12V power supply voltage signals output by the power module, so as to monitor the power supply stability of the system and actuator.

[0025] Temperature detection unit is used to collect outside temperature and inside temperature signals;

[0026] The vehicle status detection unit, power supply status detection unit, and temperature detection unit are all connected to the MCU, and convert the collected analog signals into digital signals and transmit them to the MCU for processing.

[0027] Optionally, the backlight adjustment module includes a display screen backlight circuit and a button backlight circuit. Both the display screen backlight circuit and the button backlight circuit are equipped with an adjustment tube. The control terminal of the adjustment tube is connected to the PWM control output terminal of the MCU. By adjusting the duty cycle of the PWM square wave, the illumination time ratio of the backlight is changed, thereby adjusting the brightness of the display screen and the button backlight.

[0028] Optionally, the CAN communication module uses the TJA1055T / 3 chip as a CAN transceiver.

[0029] Optionally, the vehicle air conditioning control system further includes a first backup drive circuit and a second backup drive circuit.

[0030] The first backup drive circuit is a relay control circuit. The relay input terminal is connected to the MCU's I / O interface to receive switch control signals, and the output terminal is used to connect to external extended execution components. The on / off control of external components is realized through the activation and deactivation of the relay.

[0031] The second backup drive circuit includes a transistor power amplifier. The input terminal of the transistor power amplifier is connected to the PWM control output terminal of the MCU. It receives PWM signals and outputs them after being amplified by the transistor power amplifier. It is used to drive external expansion devices that require adjustable power and realize continuous adjustment and control of their operating parameters.

[0032] Through the above technical solutions, the beneficial effects of this utility model are as follows:

[0033] 1. This application achieves high-precision detection of external temperature, internal temperature, actuator phase and power supply status through ADC detection module. Combined with three-way five-wire stepper motor drive circuit and blower closed-loop control logic, it can accurately adjust the damper opening and air volume to ensure that the cabin temperature is stable at the set value and improve comfort.

[0034] 2. Set up a first backup drive circuit and a second backup drive circuit, which respectively support the on / off control of external expansion components and adjustable power drive to meet personalized functional requirements;

[0035] 3. By using the incremental fault diagnosis signal and actuator phase feedback signal from the ADC detection module, the operating status and power supply abnormalities of the blower and damper actuator can be monitored in real time, enabling the system to quickly locate faults and maintain basic operation using default parameters, thereby improving the system's fault tolerance. Attached Figure Description

[0036] Figure 1 This is a system module structure diagram of this utility model.

[0037] Figure 2 This is a schematic diagram of a key matrix circuit according to an embodiment of the present invention.

[0038] Figure 3 This is a schematic diagram of the MCU peripheral interface circuit according to an embodiment of the present invention.

[0039] Figure 4 This is a schematic diagram of the SWD program update interface circuit according to an embodiment of the present invention.

[0040] Figure 5 This is a schematic diagram of the VN7140ASTR drive circuit according to an embodiment of the present invention.

[0041] Figure 6 This is a schematic diagram of the VNLD5300TR-E drive circuit according to an embodiment of the present invention.

[0042] Figure 7 This is a schematic diagram of a blower drive circuit according to an embodiment of the present invention.

[0043] Figure 8 This is a schematic diagram of the ADC detection module circuit according to an embodiment of the present invention.

[0044] Figure 9 This is a schematic diagram of a power module circuit according to an embodiment of the present invention.

[0045] Figure 10 This is a circuit diagram of a backlight adjustment module according to an embodiment of the present invention.

[0046] Figure 11This is a schematic diagram of a CAN communication module circuit according to an embodiment of the present invention.

[0047] Figure 12 This is a schematic diagram of the first backup drive circuit according to an embodiment of the present invention.

[0048] Figure 13 This is a schematic diagram of the second backup drive circuit according to an embodiment of the present invention.

[0049] Figure 14 This is a schematic diagram of the peripheral circuit of the BU91600FUV-ME2 chip according to an embodiment of the present invention. Detailed Implementation

[0050] The foregoing and other technical contents, features and effects of this utility model are described in conjunction with the appendix below. Figure 1 To be continued Figure 14 The detailed description of the embodiments will make this clear. All structural details mentioned in the following embodiments are based on the accompanying drawings.

[0051] Exemplary embodiments of the present invention will now be described with reference to the accompanying drawings.

[0052] like Figure 1 As shown, the vehicle air conditioning control system of this application includes a control panel, an MCU, an ADC detection module, an actuator module, a power supply module, a backlight adjustment module, and a CAN communication module.

[0053] The control panel includes an AUTO button, a front defogger button, an airflow adjustment button, an AC button, a mode adjustment button, a rear defogger button, an internal / external circulation button, an OFF button, and a temperature adjustment button. These buttons are used to receive user operation commands and transmit them to the MCU.

[0054] In one specific embodiment, such as Figure 2 and 14As shown, the control panel uses a 3*4 matrix keypad circuit. This circuit is connected to the input pins of the BU91600FUV-ME2 chip via 3 row lines and 4 column lines. Each key is connected to the intersection of the row and column lines. The BU91600FUV-ME2 chip is a feature-rich chip from ROHM, possessing not only efficient key signal processing capabilities but also the ability to be used as a display driver chip. Its built-in logic circuit can scan the changes in column line levels row by row, accurately identify key operations, and parse them into user commands. The commands are then stably transmitted to the MCU via the SPI interface, achieving an efficient processing flow from key command acquisition and parsing to transmission. When used as a display driver, this chip can work in conjunction with the control panel's display screen. After receiving relevant control signals from the MCU, it drives the display screen to normally display various parameters of the vehicle's air conditioning system, such as temperature, airflow, and operating mode. This simplifies the system hardware structure, reduces the complexity of connections between modules, and improves the integration and operational stability of the vehicle's air conditioning control system.

[0055] The MCU is connected to the control panel and configured to process input signals and output control commands. Specifically, for example... Figure 3 and 4 As shown, the MCU uses the GD32A503Cx chip. This chip connects to the control panel, ADC detection module, actuator module, backlight adjustment module and CAN communication module through multiple I / O interfaces. It is also equipped with an SWD program update interface, which enables online program updates, debugging and reading of fault diagnosis data.

[0056] The actuator module includes a blower, a hot and cold air damper actuator, a mode damper actuator, and a fresh air damper actuator. The actuator module is connected to an actuator drive circuit, which receives control commands from the MCU and drives the actuators to operate.

[0057] Specifically, the actuator drive circuit includes a stepper motor drive circuit and a blower drive circuit. The stepper motor drive circuit is used to drive the stepping action of the heating / cooling damper actuator, the mode damper actuator, and the fresh air damper actuator to adjust the damper opening; the blower drive circuit is used to control the blower speed.

[0058] In one specific embodiment, the stepper motor drive circuit adopts a three-way five-wire system, such as... Figure 5 and 6As shown, it includes five load drivers, specifically three VN7140ASTR driver chips and two VNLD5300TR-E driver chips. The input terminals of each load driver are connected to the MCU. The positive terminals of the heating / cooling damper actuator, the mode damper actuator, and the fresh air damper actuator are respectively connected to the output terminals of the three VN7140ASTR driver chips, allowing the chips to independently control the power supply to each actuator's positive terminal. The negative terminals of the three actuators share the same drive circuit, which consists of two VNLD5300TR-E driver chips and is responsible for outputting step control signals through the SETP_MOTOR_01~04 pins.

[0059] When it is necessary to control the action of a certain actuator (such as moving the mode damper actuator to position A), the MCU only sends a conduction signal to the VN7140ASTR chip of the corresponding mode actuator to energize its positive terminal. At the same time, it controls the VNLD5300TR-E chip to output a step pulse with a specific timing to the common negative terminal through the SETP pin, driving the rotor of the mode actuator to rotate to the target position. At this time, the VN7140ASTR chip of the heating / cooling and fresh air actuators remains in the off state, its positive terminal is de-energized, and it will not operate even if there is a signal on the negative terminal to avoid interference.

[0060] If multiple actuators need to be controlled sequentially (e.g., adjusting the heating / cooling damper first and then the mode damper), first power the VN7140ASTR chip of the heating / cooling actuator, drive its negative terminal through the SETP pin to complete the position adjustment, and then disconnect the power supply to the positive terminal of the heating / cooling actuator; then power the VN7140ASTR chip of the mode actuator, drive its negative terminal to complete the adjustment, and then disconnect the power, and so on.

[0061] This design, by independently controlling the positive terminal's on / off state and sharing the negative terminal's drive circuit, ensures that each actuator operates independently while reducing the use of two sets of negative terminal drive circuits, thus achieving circuit simplification and resource optimization.

[0062] like Figure 7 As shown, the blower drive circuit includes a first amplifier U11A and a second amplifier U11B.

[0063] The first amplifier U11A has its non-inverting input connected to the blower's power supply voltage and its inverting input connected to the blower's feedback terminal. It is used to calculate the blower's operating voltage and perform proportional reduction. Its output is connected to the inverting input of the second amplifier U11B. The non-inverting input of the second amplifier U11B is connected to the PWM control output of the MCU through an RC filter circuit. This RC filter circuit can convert the PWM control signal into a smooth DC control voltage. The second amplifier U11B acts as a comparator, comparing the DC control voltage at the non-inverting input with the blower's operating voltage signal at the inverting input, and outputting a corresponding level signal to control the blower's operating state.

[0064] In practical operation, the non-inverting input of U11A is connected to the blower's power supply voltage through voltage divider resistors R32 and R34, while the inverting input is connected to the blower's feedback terminal through voltage divider resistors R36 and R38. This connection is used to calculate and process the blower's operating voltage. The formula for calculating the actual operating voltage of the blower is:

[0065]

[0066] in, This is the operating voltage of the blower. Provide power voltage to the blower. This is the voltage at the blower feedback terminal.

[0067] The first amplifier U11A uses a voltage divider circuit to proportionally reduce the supply voltage and feedback voltage, and then outputs the difference signal between the two, as shown in the following formula:

[0068]

[0069] Substituting the resistor parameters: R32=5.1KΩ, R34=10KΩ, R36=10KΩ, R38=5.1KΩ, we simplify to:

[0070]

[0071] in, This is the output voltage of the first amplifier U11A.

[0072] The MCU generates a PWM control signal with an adjustable duty cycle. This signal is converted into a smooth DC control voltage by an RC filter circuit formed by resistors R17 and R62 and capacitors C126 and C127, and then input to the non-inverting input of U11B. The formula for calculating the DC control voltage is as follows: ,in, This is the filtered DC control voltage. The duty cycle of the PWM signal. This is the high-level voltage of the PWM signal.

[0073] The U11B controls the blower's operating state by comparing the DC control voltage at the non-inverting input with the blower's operating voltage signal at the inverting input and outputting a corresponding level signal: when When the output is high (12V), it drives the blower to run; when When this occurs, a low-level output (0V) stops the blower. Finally, the MCU adjusts the PWM duty cycle... Change ,make and Dynamic matching enables closed-loop control and precise speed regulation of the blower's operating voltage level.

[0074] This design not only accurately responds to airflow adjustment needs, but also compensates for speed deviations caused by load fluctuations, voltage changes, and other factors in real time, ensuring stable blower output airflow and improving system reliability.

[0075] During motor rotation, SETP_MOTOR_01~04 serve as the negative detection pins of the actuator, corresponding to specific position contacts of the heating / cooling damper, mode damper, and fresh air damper actuators, respectively. Their function is to provide feedback on the real-time position status of the actuator through level changes. By default, all four pins remain at a high level; when the actuator rotates to a target position, its internal mechanical structure will connect the corresponding negative contact with the SETP_MOTOR pin, at which point the pin level changes from high to low.

[0076] In the ADC detection module, the vehicle status detection unit collects the level signals of SETP_MOTOR_01~04 in real time, converts the analog level changes into digital signals through AD conversion, and transmits them to the MCU. The MCU accurately identifies the current mechanical position of the actuator based on the high and low level states of each pin, such as the opening position of the heating / cooling damper and the air outlet mode position of the mode damper.

[0077] The power supply status detection unit is used to detect the actuator reset power signal RES_Power and the +5V and +12V power supply voltage signals output by the power module, so as to monitor the power supply stability of the system and actuator.

[0078] The temperature detection unit is used to collect signals of the outside temperature and the inside temperature of the vehicle.

[0079] The vehicle status detection unit, power supply status detection unit, and temperature detection unit are all connected to the MCU, converting the collected analog signals into digital signals and transmitting them to the MCU for processing.

[0080] Among them, SETP_MOTOR_01~04 correspond to the phase positions of the four actuators, respectively; the INC_DIAG signal is the common fault diagnosis signal for the four actuators, reflecting whether there are faults such as jamming or disconnection in the actuators. These analog signals are transmitted to the RC low-pass filter circuit of the vehicle status detection unit through a dedicated signal line to filter out high-frequency noise and limit the voltage to a safe range of 0~5V. The conditioned signal is connected to the ADC interface of the MCU. The vehicle status detection unit triggers sampling at a frequency of 5ms / time. The MCU compares the target step number with the actual feedback step number to obtain the actual step size value. If the sampling exceeds the normal threshold for three consecutive times, a fault mark is triggered, and the default parameters are used to maintain basic operation.

[0081] Similarly, the power supply status detection unit first divides and RC filters the RES_Power, +5V, and +12V power supply signals to the 0~5V range before connecting them to the MCU's ADC interface. The signals are sampled at a frequency of 10ms / time and converted into actual voltage values. The power supply stability is monitored by threshold comparison. The temperature detection unit converts the NTC resistance changes of the external and internal temperature sensors into voltage signals. After conditioning, the signals are connected to the ADC interface and sampled at a frequency of 200ms / time. The signals are then converted into temperature values ​​through a calibration curve, providing an ambient temperature basis for air conditioning adjustment.

[0082] In the above, the power module provides +5V and +12V power to all modules in the system. For example... Figure 9 As shown, when the power module is connected to IGN_Power, reverse connection protection is first implemented through the S3M diode to prevent damage to the circuit due to incorrect connection of the positive and negative terminals of the power supply. Then, the current enters the anti-interference circuit composed of the BWMF702P302P09AV common-mode inductor and capacitor to filter out common-mode interference and high-frequency ripple, ensuring stable voltage output. Subsequently, the circuit passes through the SMBJ24CA transient suppression diode and the SMDJ36CA bidirectional transient suppression diode for surge suppression, further improving the circuit's ability to resist transient overvoltage and ensuring the stability of subsequent power supply. The processed +12V voltage directly powers high-power components such as actuators and drive circuits on one side, and is converted to +5V by the TLE42754D low-dropout linear regulator to power precision components such as the MCU and control panel. The TLE42754D also has built-in overcurrent protection, ultimately achieving stable power supply to all modules of the system.

[0083] The backlight adjustment module is used to adjust the backlight brightness of the control panel's display and buttons. Specifically, for example... Figure 10 As shown, the backlight adjustment module includes a display backlight circuit and a button backlight circuit. Both circuits contain an adjustment transistor, whose control terminal is connected to the PWM control output of the MCU. By adjusting the duty cycle of the PWM square wave, the on-time percentage of the backlight is changed, thereby adjusting the brightness of the display and button backlights. Because the PWM signal frequency is high, exceeding the human eye's resolution, the human eye perceives this periodic on / off signal as a continuous brightness change, thus achieving multi-level continuous adjustment of the backlight brightness. In this way, a clear display effect can be provided in bright light environments, while reducing brightness in dim light to reduce visual stimulation, improving the user experience under different lighting conditions and also helping to reduce energy consumption.

[0084] The CAN communication module enables message exchange between the system and the vehicle network. Specifically, for example... Figure 11As shown, the CAN communication module uses the TJA1055T / 3 chip as the CAN transceiver with a baud rate of 125kbps. It supports receiving ambient temperature messages, engine speed messages, vehicle network management messages, and switch status messages, and sends air conditioning status messages to the vehicle network.

[0085] The vehicle air conditioning control system also includes a first backup drive circuit and a second backup drive circuit. For example... Figure 12 and 13 As shown, the first backup drive circuit is a relay control circuit. The relay input terminal is connected to the MCU's I / O interface to receive switch control signals, and the output terminal is used to connect to external extended execution components. The on / off control of external components is realized by the activation and deactivation of the relay.

[0086] When external extended actuators are required, such as additional defogging devices or seat heating modules, the MCU sends high / low level switching control signals to the relay control circuit of the first backup drive circuit through the I / O interface according to system requirements or user instructions. The relay coil is energized or de-energized, causing the contacts to close or open, thereby controlling the power supply to the external extended actuators and realizing their start-up and shutdown.

[0087] The second backup drive circuit includes a transistor power amplifier. The input of the transistor power amplifier is connected to the PWM control output of the MCU. It receives the PWM signal and outputs it after amplification by the transistor. This signal is used to drive external expansion devices that require adjustable power, thereby realizing continuous adjustment and control of their operating parameters.

[0088] Specifically, the transistor power amplifier consists of a composite amplifier circuit composed of three NPN transistors. This composite amplification enhances the output current drive capability, enabling external adjustable power devices to obtain operating current proportional to the PWM duty cycle. When driving external expansion devices requiring adjustable power, such as fragrance generators or ambient lights, the MCU generates a PWM signal with a corresponding duty cycle based on set parameters. This signal is transmitted to the input of the transistor power amplifier in the second backup drive circuit. The transistors amplify the PWM signal, outputting a current or voltage matching the PWM duty cycle. By changing the output power, the operating parameters of the external expansion devices can be continuously adjusted, meeting diverse expansion function requirements.

[0089] In summary, the vehicle air conditioning control system of this application integrates core components such as a control panel, MCU, ADC detection module, and actuator module. It uses the GD32A503Cx chip as the control core, combined with a matrix keypad circuit, stepper motor drive circuit, and closed-loop control logic, achieving high precision and rapid response in air conditioning adjustment. The equipped backlight adjustment module can adaptively adjust brightness, enhancing the human-machine interaction experience. The CAN communication module ensures stable information exchange with the vehicle network. Dual backup drive circuits enhance system scalability and flexibly accommodate external devices. Simultaneously, the power module's multiple protection and anti-interference design, along with the ADC detection module's comprehensive status monitoring, significantly improves the system's stability and reliability, comprehensively meeting the comfort, intelligence, and safety requirements of modern vehicles for air conditioning systems.

[0090] The above description is a further detailed explanation of the present utility model in conjunction with specific embodiments, and it should not be considered that the specific implementation of the present utility model is limited to this. For those skilled in the art to which the present utility model pertains and related fields, any extensions, operation methods, and data substitutions made based on the technical solution concept of the present utility model should fall within the protection scope of the present utility model.

Claims

1. A vehicle air conditioning control system, characterized in that, include: The control panel features an AUTO button, a front defogger button, an airflow adjustment button, an AC button, a mode adjustment button, a rear defogger button, an internal / external circulation button, an OFF button, and a temperature adjustment button. It is used to receive user operation commands and transmit them to the MCU. The MCU is connected to the control panel and configured to process input signals and output control commands. The ADC detection module is connected to the MCU and is used to detect the vehicle status signal, power supply status signal, and cabin temperature signals. The actuator module includes a blower, a hot and cold air damper actuator, a mode damper actuator, and a fresh air damper actuator. The actuator module is connected to an actuator drive circuit, which receives control commands from the MCU and drives the actuators to operate. The power module provides +5V and +12V power to all modules in the system. A backlight adjustment module, connected to the MCU, is used to adjust the backlight brightness of the control panel's display screen and buttons; The CAN communication module is connected to the MCU to enable message interaction between the system and the vehicle network.

2. The vehicle air conditioning control system according to claim 1, characterized in that, The control panel uses a 3*4 matrix keypad circuit. This circuit is connected to the input pins of the BU91600FUV-ME2 chip through 3 row lines and 4 column lines. Each key is connected to the intersection of the row line and the column line. The BU91600FUV-ME2 chip scans the changes in the column line level row by row through its built-in logic circuit, identifies the key operation, parses it into user instructions, and then transmits the instructions to the MCU through the SPI interface.

3. The vehicle air conditioning control system according to claim 2, characterized in that, The MCU uses the GD32A503Cx chip. The MCU is connected to the control panel, ADC detection module, actuator module, backlight adjustment module and CAN communication module through multiple I / O interfaces. It is also equipped with an SWD program update interface to realize program updates and debugging.

4. The vehicle air conditioning control system according to claim 3, characterized in that, The actuator drive circuit includes a stepper motor drive circuit and a blower drive circuit; The stepper motor drive circuit is used to drive the stepping action of the heating and cooling damper actuator, the mode damper actuator, and the fresh air damper actuator to adjust the damper opening. The blower drive circuit is used to control the wind speed adjustment of the blower.

5. A vehicle air conditioning control system according to claim 4, characterized in that, The stepper motor drive circuit includes multiple load drivers. The input terminal of the load driver is connected to the MCU, and the output terminal of the load driver is connected to the coil windings of the heating / cooling damper actuator, the mode damper actuator, and the fresh air damper actuator, respectively. By controlling the energizing sequence and current magnitude of each phase winding, the corresponding stepper motor is driven to achieve angle adjustment and position control.

6. A vehicle air conditioning control system according to claim 5, characterized in that, The blower drive circuit includes a first amplifier and a second amplifier; The non-inverting input of the first amplifier is connected to the blower's power supply voltage, and the inverting input is connected to the blower's feedback terminal. This is used to calculate the blower's operating voltage and perform a proportional reduction. Its output is connected to the inverting input of the second amplifier. The non-inverting input of the second amplifier is connected to the PWM control output of the MCU through an RC filter circuit to convert the PWM control signal into a smooth DC control voltage. The second amplifier compares the DC control voltage at the non-inverting input with the blower operating voltage signal at the inverting input and outputs a corresponding level signal to control the working state of the blower.

7. A vehicle air conditioning control system according to claim 6, characterized in that, The ADC detection module includes: The vehicle status detection unit is used to detect the phase feedback signals and fault diagnosis incremental signals of the blower, heating and cooling damper actuator, mode damper actuator and fresh air damper actuator, so as to monitor the operating status and fault information of each actuator. The power supply status detection unit is used to detect the actuator reset power signal RES_Power and the +5V and +12V power supply voltage signals output by the power module, so as to monitor the power supply stability of the system and actuator. The temperature detection unit is used to collect signals of the outside temperature and the inside temperature of the vehicle. The vehicle status detection unit, power supply status detection unit, and temperature detection unit are all connected to the MCU, and the collected analog signals are converted into digital signals and transmitted to the MCU for processing.

8. A vehicle air conditioning control system according to claim 7, characterized in that, The backlight adjustment module includes a display screen backlight circuit and a button backlight circuit. Both the display screen backlight circuit and the button backlight circuit are equipped with an adjustment tube. The control terminal of the adjustment tube is connected to the PWM control output terminal of the MCU. By adjusting the duty cycle of the PWM square wave, the illumination time ratio of the backlight is changed, thereby adjusting the brightness of the display screen and the button backlight.

9. A vehicle air conditioning control system according to claim 8, characterized in that, The CAN communication module uses the TJA1055T / 3 chip as the CAN transceiver.

10. A vehicle air conditioning control system according to claim 9, characterized in that, The vehicle air conditioning control system also includes a first backup drive circuit and a second backup drive circuit. The first backup drive circuit is a relay control circuit. The relay input terminal is connected to the MCU's I / O interface to receive switch control signals, and the output terminal is used to connect to external extended execution components. The on / off control of external components is realized through the activation and deactivation of the relay. The second backup drive circuit includes a transistor power amplifier. The input terminal of the transistor power amplifier is connected to the PWM control output terminal of the MCU. It receives PWM signals and outputs them after being amplified by the transistor power amplifier. It is used to drive external expansion devices that require adjustable power and realize continuous adjustment and control of their operating parameters.

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