Automotive solenoid valve compatible control system and readable storage medium

Abstract

This invention provides a compatible control system for automotive solenoid valves and a readable storage medium, comprising: determining whether the target current of the solenoid valve exceeds the maximum closed-loop control current supported by the driver chip; if so, switching the driver chip to a current soft control mode; if not, switching the driver chip to a current hard control mode; wherein, the current hard control mode includes: the driver chip controlling the current of the solenoid valve in a closed loop; the current soft control mode includes: the driver chip feeding back the current information of the solenoid valve to the microcontroller unit, enabling the microcontroller unit to control the current of the solenoid valve in a closed loop. Through the automotive solenoid valve compatible control system and readable storage medium provided by this invention, the switching between different current control modes solves the problem of incompatibility for different types of solenoid valve drives in the prior art.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and in particular to a vehicle-compatible solenoid valve control system. Background Technology

[0002] Many devices in a vehicle require the use of solenoid valves for control. These solenoid valves include variable damping shock absorber solenoid valves, air suspension air distribution valves, four-wheel drive disconnect solenoid valves, active stabilizer bar mode solenoid valves, and thermal management SOV valves.

[0003] These solenoid valves can be divided into three categories based on their control method. The first category is the ON / OFF control type, such as air suspension air distribution valves and thermal management SOV valves. The control method for this type of solenoid valve is relatively simple; the valve's opening and closing is controlled by switching the voltage across its terminals between 0V and 12V. The control principle and method of this type of solenoid valve are as follows: Figure 1 and Figure 2 As shown.

[0004] The second type is the proportional solenoid valve, such as the solenoid valve for a variable resistance damper. This type of solenoid valve requires pulse width modulation (PWM) control to stabilize the current flowing through the valve, thereby controlling the valve opening. This necessitates a current closed-loop control system at the control end. Based on a comparison of the target current and the feedback current, it outputs PWM signals with different duty cycles to stabilize the solenoid valve current near the target current. The control principles and methods for this type of solenoid valve are as follows: Figure 3 , 4 As shown.

[0005] For proportional solenoid valves such as variable resistance damper solenoid valves, the maximum drive current of the solenoid valve generally does not exceed 2A. In terms of hardware design, integrated chips are generally selected for driving. Such drive chips include Infineon's TLE8242 and STMicroelectronics' L9305.

[0006] The third type is the peak-hold control type solenoid valve, also known as a peak-hold solenoid valve. The control circuit of this type of solenoid valve is the same as that of a proportional solenoid valve. Figure 3 This type of control circuit, but the control method is as follows: Figure 5 As shown, the control principle is the same as that of a proportional solenoid valve; both achieve closed-loop current control by collecting the current of the solenoid valve.

[0007] For these three types of solenoid valves with different control requirements, the controller drive should be designed to be compatible to achieve platformization. This will minimize controller development and material costs while meeting customer needs. For the first type of solenoid valve, compatibility with common load controls is desired. For example, the output of headlight control can be selected for compatibility, as they both use high-side switches for ON / OFF control, and compatibility is achieved as long as the load current is similar. For the second and third types of solenoid valves, compatibility is also desired. A drive circuit designed for a proportional solenoid valve can also be used to drive a peak-hold solenoid valve, and vice versa.

[0008] However, the current design cannot meet the compatibility requirements for driving both Class II and Class III solenoid valves. For example, for proportional solenoid valves, such as... Figure 4 The control method shown has a maximum current of 2A, so when selecting a driver chip, we would typically choose STMicroelectronics' L9305. However, checking the chip's specifications reveals that the L9305 only supports 2A current control closed-loop control, which is insufficient to meet the requirements. Figure 5 The Peak-Hold solenoid valve's maximum current requirement of 2.5A makes compatibility impossible. To achieve compatibility, the L9352 would need to be selected. The L9352 supports 5A current closed-loop control, but using the L9352 for compatibility presents two problems:

[0009] (1) The cost has increased significantly. It is obvious that the L9352, which has a stronger driving capability, costs more than the L9305.

[0010] (2) Increased driving capability leads to increased error in low current control. The control error of L9305 in the range of 0A~0.5A is only 5mA, while the control error of L9352 in the range of 0A~0.5A is 25mA. Summary of the Invention

[0011] The present invention aims to provide a vehicle solenoid valve compatible control system to solve the problem that the prior art cannot be compatible with the drive of different types of solenoid valves.

[0012] To address the above problems, the present invention provides a vehicle-grade solenoid valve compatible control system, comprising: a microcontroller unit and a drive chip;

[0013] The driver chip has a current hard control mode and a current soft control mode for controlling the current of the solenoid valve.

[0014] The microcontroller unit is configured to determine whether the target current of the solenoid valve exceeds the maximum closed-loop control current that the drive chip can support. If so, the drive chip is switched to current soft control mode; if not, the drive chip is switched to current hard control mode.

[0015] The current hard control mode includes: the driver chip controls the current of the solenoid valve in a closed loop; the current soft control mode includes: the driver chip feeds back the current information of the solenoid valve to the microcontroller unit, so that the microcontroller unit controls the current of the solenoid valve in a closed loop.

[0016] Optionally, in the aforementioned automotive solenoid valve compatible control system, the microcontroller unit is further configured to sample the voltage of the power supply; if the voltage of the power supply exceeds a set voltage, it controls the high-side switch used to connect the power supply to the solenoid valve to disconnect and records a power undervoltage fault.

[0017] Optionally, in the aforementioned automotive solenoid valve compatible control system, the microcontroller unit has an IN1 pin and an OUT1 pin. The microcontroller unit samples the voltage of the power supply through the IN1 pin and controls the on / off state of the high-side switch connecting the power supply and the solenoid valve through the OUT1 pin.

[0018] Optionally, in the aforementioned automotive solenoid valve compatible control system, the microcontroller unit is further configured to perform closed-loop control of the solenoid valve with a target current exceeding the maximum closed-loop control current supported by the drive chip for a duration not exceeding a set time.

[0019] Optionally, in the aforementioned automotive solenoid valve compatible control system, the method by which the microcontroller determines whether the set time has been exceeded includes:

[0020] The timing begins when the solenoid valve is subjected to a target current exceeding the maximum closed-loop control current supported by the driver chip. If the timing exceeds the set time, the closed-loop control of the solenoid valve with the target current exceeding the maximum closed-loop control current supported by the driver chip is stopped.

[0021] Optionally, in the aforementioned automotive solenoid valve compatible control system, the drive chip is electrically connected to the solenoid valve via a low-side switch, and both the drive chip and the microcontroller control unit control the current of the solenoid valve by controlling the on / off state of the low-side switch.

[0022] Optionally, in the aforementioned automotive solenoid valve compatible control system, the driving chip has a first SPI interface, an INX pin, and the low-side switch, and the microcontroller has a second SPI interface and an OUT2 pin. The microcontroller is electrically connected to the first SPI interface of the driving chip through the second SPI interface to send SPI commands to the driving chip and receive the current information fed back by the driving chip, and is electrically connected to the INX pin through the OUT2 pin to control the on / off state of the low-side switch.

[0023] Optionally, in the aforementioned automotive solenoid valve compatible control system, both the drive chip and the microcontroller unit control the on / off state of the low-side switch by outputting different pulse width modulation signals.

[0024] Optionally, in the aforementioned automotive solenoid valve compatible control system, the drive chip is a drive chip for controlling the proportional solenoid valve current. If the maximum closed-loop control current supported by the drive chip is greater than the target current value of the peak stage of the solenoid valve current in the peak-hold control type, and less than the target current value of the solenoid valve current holding stage in the peak-hold control type, then:

[0025] During its peak current phase, the current soft control mode is used for control.

[0026] During its current holding phase, the current hard control mode is used for control.

[0027] The present invention also provides a readable storage medium storing a computer program, which, when executed, performs the following steps:

[0028] Determine whether the target current of the solenoid valve exceeds the maximum closed-loop control current that the driver chip can support. If so, switch the mode of the driver chip to current soft control mode; otherwise, switch the mode of the driver chip to current hard control mode.

[0029] The current hard control mode includes: the driver chip controls the current of the solenoid valve in a closed loop; the current soft control mode includes: the driver chip feeds back the current information of the solenoid valve to the microcontroller unit, so that the microcontroller unit controls the current of the solenoid valve in a closed loop.

[0030] In summary, the automotive solenoid valve compatible control system and readable storage medium provided by this invention include: determining whether the target current of the solenoid valve exceeds the maximum closed-loop control current supported by the driver chip; if so, switching the driver chip's mode to a current soft control mode; if not, switching the driver chip's mode to a current hard control mode; wherein, the current hard control mode includes: the driver chip controlling the current of the solenoid valve in a closed loop; the current soft control mode includes: the driver chip feeding back the current information of the solenoid valve to the microcontroller unit, enabling the microcontroller unit to control the current of the solenoid valve in a closed loop. Through the automotive solenoid valve compatible control system and readable storage medium provided by this invention, the switching between different current control modes solves the problem of incompatibility for driving different types of solenoid valves in the prior art. Attached Figure Description

[0031] Figure 1 A schematic diagram of the control principle of an ON / OFF control type solenoid valve;

[0032] Figure 2 A schematic diagram of the control method for an ON / OFF control type solenoid valve;

[0033] Figure 3 This is a schematic diagram illustrating the control principle of a proportional solenoid valve and a Peak-hold solenoid valve.

[0034] Figure 4 This is a schematic diagram of the control method for a proportional solenoid valve.

[0035] Figure 5 This is a schematic diagram of the control method for the Peak-hold solenoid valve;

[0036] Figure 6 This is a schematic diagram illustrating the control principle of the automotive solenoid valve compatible control system provided by the present invention. Detailed Implementation

[0037] To make the objectives, advantages, and features of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to facilitate and clearly illustrate the objectives of the embodiments of this invention. Furthermore, the structures shown in the drawings are often part of the actual structures. In particular, different figures may emphasize different aspects and sometimes use different scales. It should also be understood that, unless specifically stated or indicated, the terms "first," "second," "third," etc., in the specification are only used to distinguish the various components, elements, steps, etc., in the specification, and are not used to indicate the logical or sequential relationships between the various components, elements, steps, etc.

[0038] Please see Figure 6This invention provides a vehicle-grade solenoid valve compatible control system, including: a microcontroller unit (MCU) and a driver chip; the driver chip has a current hard control mode and a current soft control mode for controlling the current of the solenoid valve; the MCU is configured to determine whether the target current of the solenoid valve exceeds the maximum closed-loop control current that the driver chip can support, and if so, switch the mode of the driver chip to the current soft control mode, and if not, switch the mode of the driver chip to the current hard control mode.

[0039] The current hard control mode includes: the driver chip controls the current of the solenoid valve in a closed loop; the current soft control mode includes: the driver chip feeds back the current information of the solenoid valve to the MCU, so that the MCU controls the current of the solenoid valve in a closed loop.

[0040] In practical applications, the automotive solenoid valve compatible control method can be applied to control the valve opening of a peak-hold control type solenoid valve (i.e., a Peak-Hold solenoid valve) using a proportional solenoid valve driver chip. If the maximum closed-loop control current of the driver chip is greater than the target current of the Peak-Hold solenoid valve during the current holding phase (i.e., the Hold phase) but less than the target current of the Peak-Hold solenoid valve during the current peak phase (i.e., the Peak phase), then during the Peak phase of the Peak-Hold solenoid valve, the current of the Peak-Hold solenoid valve is controlled using the current soft control mode. This avoids thermal risks and electrical overstress (EOS) damage to the proportional solenoid valve driver chip. During the Hold phase of the Peak-Hold solenoid valve, the current of the Peak-Hold solenoid valve is controlled using the current hard control mode, which also avoids thermal risks and EOS damage to the proportional solenoid valve driver chip.

[0041] For example, as mentioned earlier, the L9305 driver chip used to control the proportional solenoid valve can support a closed-loop control current of 2A. The target current for the Peak-Hold solenoid valve in the Peak phase is 2.5A, and the target current in the Hold phase is 1.5A. Since the closed-loop control current supported by the L9305 is 2A, which is less than 2.5A, the soft current control mode is used in the Peak phase of the Peak-Hold solenoid valve, and the hard current control mode is used in the Hold phase. Because the Peak phase is relatively short, such as... Figure 3 As shown, it is generally only 500ms. The driving chip can drive a current of 2.5A within 500ms without causing thermal risk or EOS risk to the chip.

[0042] It should be noted that although the automotive solenoid valve compatible control method provided in the embodiments of the present invention is applicable to controlling the valve opening of a peak-hold control type solenoid valve using a proportional solenoid valve drive chip, this application is not limited thereto. For example, in some specific scenarios, if the solenoid valve has different opening requirements, causing the target current to change in stages, and the target current in some stages is greater than the maximum closed-loop control current of the drive chip used, then the automotive solenoid valve compatible control method provided in the embodiments of the present invention can also be used.

[0043] As can be seen from the above description, the automotive solenoid valve compatible control system provided by the embodiments of the present invention solves the problem of incompatibility with different types of solenoid valve drives in the prior art by switching between different current control modes.

[0044] The automotive solenoid valve compatible control system provided in this embodiment of the invention includes a driver chip electrically connected to the solenoid valve via a low-side switch. Both the driver chip and the MCU control the current of the solenoid valve by controlling the on / off state of the low-side switch. The corresponding circuit configuration is as follows: the driver chip has a first SPI interface, an INX pin, and the low-side switch; the MCU has a second SPI interface and an OUT2 pin. The MCU is electrically connected to the first SPI interface of the driver chip via the second SPI interface to send SPI commands to the driver chip and receive the current information fed back by the driver chip; and it is electrically connected to the INX pin via the OUT2 pin to control the on / off state of the low-side switch.

[0045] That is, when the proportional solenoid valve's driver chip is used to drive the Peak-Hold solenoid valve, in the Peak phase, the MCU obtains the solenoid valve's current feedback information through the driver chip's first SPI interface, compares the current feedback information with the target current to form a current closed-loop control, and then outputs a PWM signal through the OUT2 pin to control the solenoid valve current to reach the target current. In the Hold phase, the MCU first configures the driver chip's mode from current soft control mode to current hard control mode through SPI instructions, and then sends the target current to the driver chip through SPI instructions. The driver chip's internal hardware current closed-loop circuit then realizes the target current output.

[0046] Both the driver chip and the MCU can control the on / off state of the low-side switch by outputting different pulse width modulation (PWM) signals. Specifically, the driver chip's closed-loop control of the solenoid valve's current includes: acquiring the solenoid valve's current feedback information, comparing the current feedback information with the target current, and outputting a PWM signal with a corresponding duty cycle based on the comparison result to control the on / off state of the low-side switch, thereby stabilizing the actual current of the solenoid valve at the target current. Similarly, the MCU's closed-loop control of the solenoid valve's current includes: comparing the solenoid valve's current feedback information acquired from the driver chip with the target current, and outputting a PWM signal with a corresponding duty cycle based on the comparison result to control the on / off state of the low-side switch, thereby stabilizing the actual current of the solenoid valve at the target current.

[0047] In addition to the driver chip forming a high-side channel by electrically connecting one end of the solenoid valve to the low-side switch, when controlling the proportional solenoid valve or Peak-Hold solenoid valve, the power supply forms a low-side channel by electrically connecting the other end of the solenoid valve to the high-side switch. The high-side channel and the low-side channel are electrically connected by a diode.

[0048] Preferably, the MCU is further configured to sample the voltage of the power supply. If the voltage of the power supply exceeds a set voltage, the MCU controls the high-side switch connecting the power supply and the solenoid valve to disconnect and records a power undervoltage fault. The corresponding circuit is configured such that the MCU has an IN1 pin and an OUT1 pin. The MCU samples the voltage of the power supply through the IN1 pin and controls the on / off state of the high-side switch connecting the power supply and the solenoid valve through the OUT1 pin. The set voltage can be set according to actual conditions. For example, the set voltage can be 9V. When the power supply voltage is less than 9V, it is considered that normal control cannot be completed, and the high-side power supply to the solenoid valve is shut off through OUT1.

[0049] Preferably, the MCU is further configured to ensure that the duration of closed-loop control of the solenoid valve with a target current exceeding the maximum closed-loop control current supported by the driver chip does not exceed a set time. Specifically, the current output to the solenoid valve can be timed in software. The timing begins when closed-loop control of the solenoid valve with a target current exceeding the maximum closed-loop control current supported by the driver chip begins. If the timing exceeds the set time, closed-loop control of the solenoid valve with a target current exceeding the maximum closed-loop control current supported by the driver chip stops. For example,

[0050] When the Peak phase begins, the software activates timing monitoring to ensure that the Peak phase duration does not exceed a set time. This protects the driver chip from overheating and damage due to prolonged Peak phase. The set time can be configured according to specific circumstances; for example, it can be 1 second.

[0051] The MCU's software timing protection function and undervoltage protection function can be selectively enabled. The software timing protection function can be disabled if the driver chip has built-in temperature protection. Undervoltage protection can also be disabled if it is ensured that undervoltage driving will not cause damage (including personal injury and equipment).

[0052] This invention also provides a readable storage medium storing a computer program. When the computer program is executed, it performs the following steps: determining whether the target current of the solenoid valve exceeds the maximum closed-loop control current supported by the driver chip; if so, switching the driver chip to a current soft control mode; if not, switching the driver chip to a current hard control mode; wherein, the current hard control mode includes: the driver chip controlling the current of the solenoid valve in a closed loop; the current soft control mode includes: the driver chip feeding back the current information of the solenoid valve to the microcontroller unit, so that the microcontroller unit controls the current of the solenoid valve in a closed loop.

[0053] The readable storage medium can be any medium capable of storing program code, such as a mobile storage device, read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk. It can be integrated into the microcontroller unit to implement the above-mentioned compatible control scheme.

[0054] In summary, the automotive solenoid valve compatible control system and readable storage medium provided by this invention include: determining whether the target current of the solenoid valve exceeds the maximum closed-loop control current supported by the driver chip; if so, switching the driver chip's mode to a current soft control mode; if not, switching the driver chip's mode to a current hard control mode; wherein, the current hard control mode includes: the driver chip controlling the current of the solenoid valve in a closed loop; the current soft control mode includes: the driver chip feeding back the current information of the solenoid valve to the microcontroller unit, so that the microcontroller unit controls the current of the solenoid valve in a closed loop. Through the automotive solenoid valve compatible control system and readable storage medium provided by this invention, the switching between different current control modes solves the problem of incompatibility for driving different types of solenoid valves in the prior art.

[0055] Furthermore, it should be understood that although the present invention has been disclosed above with reference to preferred embodiments, these embodiments are not intended to limit the present invention. For any person skilled in the art, many possible variations and modifications can be made to the technical solutions of the present invention based on the disclosed technical content, or equivalent embodiments with equivalent changes, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the present invention shall still fall within the scope of protection of the present invention.

Claims

1. A vehicle-grade solenoid valve compatible control system, characterized in that, include: Microcontroller unit and driver chip; The driver chip has a current hard control mode and a current soft control mode for controlling the current of the solenoid valve. The microcontroller unit is configured to determine whether the target current of the solenoid valve exceeds the maximum closed-loop control current that the drive chip can support. If so, the drive chip is switched to current soft control mode; if not, the drive chip is switched to current hard control mode. The current hard control mode includes: the driver chip controls the current of the solenoid valve in a closed loop; the current soft control mode includes: the driver chip feeds back the current information of the solenoid valve to the microcontroller unit, so that the microcontroller unit controls the current of the solenoid valve through the low-side switch of the driver chip.

2. The automotive solenoid valve compatible control system as described in claim 1, characterized in that, The microcontroller unit is also configured to sample the voltage of the power supply, and if the voltage of the power supply exceeds a set voltage, control the high-side switch used to connect the power supply to the solenoid valve to disconnect, and record the power supply undervoltage fault.

3. The automotive solenoid valve compatible control system as described in claim 2, characterized in that, The microcontroller has an IN1 pin and an OUT1 pin. The microcontroller samples the voltage of the power supply through the IN1 pin and controls the on / off state of the high-side switch connecting the power supply and the solenoid valve through the OUT1 pin.

4. The automotive solenoid valve compatible control system as described in claim 1, characterized in that, The microcontroller unit is also configured to perform closed-loop control of the solenoid valve with a target current exceeding the maximum closed-loop control current that the drive chip can support for a duration not exceeding a set time.

5. The automotive solenoid valve compatible control system as described in claim 4, characterized in that, The method by which the microcontroller determines whether the set time has been exceeded includes: The timing begins when the solenoid valve is subjected to a target current exceeding the maximum closed-loop control current supported by the driver chip. If the timing exceeds the set time, the closed-loop control of the solenoid valve with the target current exceeding the maximum closed-loop control current supported by the driver chip is stopped.

6. The automotive solenoid valve compatible control system as described in claim 1, characterized in that, The driving chip is electrically connected to the solenoid valve via a low-side switch. Both the driving chip and the microcontroller control unit control the current of the solenoid valve by controlling the on / off state of the low-side switch.

7. The automotive solenoid valve compatible control system as described in claim 6, characterized in that, The driver chip has a first SPI interface, an INX pin, and the low-side switch. The microcontroller has a second SPI interface and an OUT2 pin. The microcontroller is electrically connected to the first SPI interface of the driver chip through the second SPI interface to send SPI commands to the driver chip and receive the current information fed back by the driver chip. It is also electrically connected to the INX pin through the OUT2 pin to control the on / off state of the low-side switch.

8. The automotive solenoid valve compatible control system as described in claim 6, characterized in that, Both the driver chip and the microcontroller control unit control the on / off state of the low-side switch by outputting different pulse width modulation signals.

9. The automotive solenoid valve compatible control system as described in claim 1, characterized in that, The driving chip is a driving chip for controlling the current of a proportional solenoid valve. If the maximum closed-loop control current that the driving chip can support is greater than the target current value of the peak stage of the solenoid valve current in the peak-hold control type, and less than the target current value of the solenoid valve current holding stage in the peak-hold control type, then: During its peak current phase, the current soft control mode is used for control. During its current holding phase, the current hard control mode is used for control.

10. A readable storage medium, characterized in that, The readable storage medium stores a computer program, which, when executed, performs the following steps: determining whether the target current of the solenoid valve exceeds the maximum closed-loop control current that the drive chip can support; if so, switching the mode of the drive chip to current soft control mode; if not, switching the mode of the drive chip to current hard control mode. The current hard control mode includes: the driver chip controls the current of the solenoid valve in a closed loop; the current soft control mode includes: the driver chip feeds back the current information of the solenoid valve to the microcontroller unit, so that the microcontroller unit controls the current of the solenoid valve through the low-side switch of the driver chip.

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