Electromagnetic valve driving circuit, method and equipment and vehicle

Abstract

The invention discloses an electromagnetic valve driving circuit, method and device and a vehicle, the electromagnetic valve driving circuit comprises a DCDC power supply chip, a current recovery module and a feedback voltage adjusting module, the input end of the DCDC power supply chip is connected with an external power supply, the output end of the DCDC power supply chip is connected with a driven electromagnetic valve, and the feedback end of the DCDC power supply chip is connected with the feedback voltage adjusting module; the current recovery module is connected between the output end of the DCDC power supply chip and the electromagnetic valve, the first input end of the feedback voltage adjusting module is connected with the output end of the current recovery module, and the second input end of the feedback voltage adjusting module receives a second electric signal input from the outside. According to the embodiment of the invention, the electromagnetic valve is driven based on the electromagnetic valve driving circuit, and the problems of EMI interference, large noise and slow response in the existing electromagnetic valve driving scheme are solved.

Description

Technical Field

[0001] The present application belongs to the field of electronic circuit technology, and in particular, relates to a solenoid valve drive circuit, method, device and vehicle. Background Art

[0002] With the development of technology, in order to meet people's demand for car comfort, the functions of various ECUs (Electronic Control Units) in the car are becoming more and more powerful, and there are more and more types of motors and solenoid valves. For BCM (Body Control Module), the circuit requirements for driving various solenoid valves are becoming more and more stringent.

[0003] Currently, the more common solenoid valve drive circuit is a pre-drive chip plus a MOS tube. The control principle is that the MCU (Microcontroller Unit) collects the load current and then adjusts the output target drive current by controlling the PWM duty cycle of the MOS tube.

[0004] The defects of the above-mentioned driving circuit mainly include: the PWM driving signal at the output end will generate EMI (Electromagnetic Interference), which will be transmitted through the wiring harness and will also affect other ECUs. Moreover, for the solenoid valves that work all the time, the PWM driving signal at the output end may generate noise that is perceptible to the human ear. In addition, this software PID (Proportion Integral Derivative Programmable Logic Controller) adjustment method, which collects current through MCU software and then adjusts the output, has a relatively long response time, affecting the user experience. Summary of the invention

[0005] The embodiments of the present application provide a solenoid valve driving circuit, method, device and vehicle, which can solve the problems of EMI interference, high noise and slow response in the existing solenoid valve driving scheme.

[0006] In a first aspect, an embodiment of the present application provides a solenoid valve drive circuit, comprising: a DCDC power supply chip, a current recovery module and a feedback voltage adjustment module;

[0007] The input end of the DCDC power chip is connected to the external power supply, the output end of the DCDC power chip is connected to the driven solenoid valve, and the feedback end of the DCDC power chip is connected to the output end of the feedback voltage adjustment module;

[0008] The current recovery module is connected between the output end of the DCDC power chip and the solenoid valve;

[0009] One input end of the feedback voltage adjustment module is connected to the output end of the current recovery module, and another input end of the feedback voltage adjustment module is used to receive a second electrical signal input from the outside, wherein the second electrical signal is an electrical signal corresponding to the target value of the driving current;

[0010] The current collection module is used to collect the output current value of the DCDC power chip and output a first electrical signal corresponding to the output current value;

[0011] The feedback voltage adjustment module is used to adjust the voltage of the feedback terminal based on the first electrical signal and the second electrical signal;

[0012] The DCDC power chip is used to output a driving voltage signal based on the voltage at the feedback end, and the driving signal is used to drive the solenoid valve.

[0013] In a second aspect, an embodiment of the present application provides a solenoid valve driving method, which is implemented based on the solenoid valve driving circuit of the first aspect, and includes:

[0014] The current recovery circuit collects the output current value of the DCDC power chip and outputs a first electrical signal corresponding to the output current value;

[0015] The feedback voltage adjustment module adjusts the voltage of the feedback terminal of the DCDC power chip based on the first electrical signal and the second electrical signal input externally, wherein the second electrical signal is an electrical signal corresponding to the target value of the driving current;

[0016] The DCDC power chip outputs a driving voltage signal for driving the solenoid valve based on the voltage at the feedback terminal.

[0017] In a third aspect, an embodiment of the present application provides a device having a solenoid valve, wherein the device includes the solenoid valve drive circuit described in the first aspect.

[0018] In a fourth aspect, an embodiment of the present application provides a vehicle, comprising the solenoid valve drive circuit described in the first aspect.

[0019] The solenoid valve driving circuit, method, device and vehicle of the embodiment of the present application, the solenoid valve driving circuit includes a DCDC power chip, a current recovery module and a feedback voltage adjustment module, the input end of the DCDC power chip is connected to an external power supply, the output end is connected to the driven solenoid valve, the feedback end is connected to the feedback voltage adjustment module, the current recovery module is connected between the output end of the DCDC power chip and the solenoid valve, the first input end of the feedback voltage adjustment module is connected to the output end of the current recovery module, and the second input end receives a second electrical signal input from the outside. According to the embodiment of the present application, the voltage at the feedback end of the DCDC power chip can be automatically adjusted based on the second electrical signal, so that the DCDC power chip outputs an adjustable power voltage signal for driving the load. Since the DCDC power chip outputs a dynamically adjustable voltage signal instead of a PWM signal, EMI interference will not be generated through the wiring harness. Since the DCDC power chip outputs a PWM signal instead of a PWM signal, no noise perceptible to the human ear will be generated. Moreover, compared with the hardware PID adjustment method, the external controller only provides a control signal and does not participate in the PID adjustment process, so the circuit response is faster. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solution of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0021] Figure 1 It is a structural schematic diagram of a solenoid valve drive circuit provided by an embodiment of the present application;

[0022] Figure 2 is a structural schematic diagram of a solenoid valve drive circuit provided by another embodiment of the present application;

[0023] Figure 3 is a structural schematic diagram of a solenoid valve drive circuit provided by another embodiment of the present application;

[0024] Figure 4 is a structural schematic diagram of a solenoid valve drive circuit provided by another embodiment of the present application;

[0025] Figure 5 is a structural schematic diagram of a solenoid valve drive circuit provided by another embodiment of the present application;

[0026] Figure 6 is a structural schematic diagram of a solenoid valve drive circuit provided by another embodiment of the present application;

[0027] Figure 7 is a structural schematic diagram of a solenoid valve drive circuit provided by another embodiment of the present application;

[0028] Figure 8 is a structural schematic diagram of a solenoid valve drive circuit provided by another embodiment of the present application;

[0029] Fig. 9 It is a flow chart of a solenoid valve driving method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0030] In order to more clearly understand the above-mentioned objectives, features and advantages of the present disclosure, the scheme of the present disclosure will be further described below. It should be noted that the embodiments of the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0031] In the following description, many specific details are set forth to facilitate a full understanding of the present disclosure, but the present disclosure may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present disclosure, rather than all of the embodiments.

[0032] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0033] In order to solve the technical problems existing in the prior art, the embodiments of the present application provide a new type of solenoid valve drive circuit, method, device and vehicle.

[0034] See also Figure 1 , is a schematic diagram of a solenoid valve drive circuit provided in an embodiment of the present application, such as Figure 1 As shown, the solenoid valve drive circuit may include:

[0035] DCDC power chip 110 , current recovery module 120 and feedback voltage adjustment module 130 .

[0036] The DCDC power chip 110 is a Direct Current to Direct Current power chip, that is, a DC voltage converter, and its model can be selected according to the working current requirement of the solenoid valve to ensure that the output current of the DCDC power chip 110 can meet the working current of the solenoid valve.

[0037] The DCDC power chip 110 includes an input terminal, an output terminal and a feedback terminal. Its working principle includes outputting voltage signals of different powers by adjusting the voltage of the feedback terminal, that is, the power of the output voltage signal can be adjusted according to the feedback voltage.

[0038] like Figure 1 As shown, the input end of the DCDC power chip 110 is connected to the external power supply, the output end of the DCDC power chip 110 is connected to the driven solenoid valve, and the feedback end of the DCDC power chip 110 is connected to the feedback voltage adjustment module 130 .

[0039] The current recovery module 120 is connected between the output end of the DCDC power chip 110 and the solenoid valve.

[0040] One input end of the feedback voltage adjustment module 130 is connected to the output end of the current recovery module 120, and the other input end of the feedback voltage adjustment module 130 is used to receive a second electrical signal input from the outside, wherein the second electrical signal is an electrical signal corresponding to a drive current target value, and the drive current target value is a current value set according to actual conditions for driving the solenoid valve, such as a starting current value, a holding current value, etc. of the solenoid valve.

[0041] The current collection module 120 is used to collect the output current value of the DCDC power chip 110 and output a first electrical signal corresponding to the output current value.

[0042] The feedback voltage adjustment module 130 is used to adjust the voltage of the feedback terminal of the DCDC power chip 110 based on the first electrical signal and the second electrical signal.

[0043] The DCDC power chip 110 is used to output a driving voltage signal for driving the solenoid valve based on the voltage at the feedback terminal.

[0044] In the prior art, the solenoid valve is mainly driven by a pre-drive chip plus a MOS tube. The driving process mainly includes adjusting the output target drive current by controlling the PWM duty cycle of the MOS tube after the MCU collects the load current. This driving method has the following technical problems: First, the output PWM drive signal will generate EMI interference and be transmitted through the wiring harness to affect other ECUs; second, for solenoid valves that work all the time, the output PWM drive signal may generate noise that can be perceived by the human ear; third, the software PID adjustment method of the MCU software collecting current and then adjusting the output has a long response time, which affects the customer experience. The solenoid valve drive circuit provided in the embodiment of the present application includes a DCDC power chip, a current collection module and a feedback voltage adjustment module. The input end of the DCDC power chip is connected to an external power supply, the output end is connected to the driven solenoid valve, the feedback end is connected to the feedback voltage adjustment module, the current collection module is connected between the output end of the DCDC power chip and the solenoid valve, the first input end of the feedback voltage adjustment module is connected to the output end of the current collection module, and the second input end receives a second electrical signal input from the outside. According to the embodiment of the present application, the voltage at the feedback end of the DCDC power chip can be automatically adjusted based on the second electrical signal, so that the DCDC power chip outputs an adjustable power voltage signal for driving the load. Since the DCDC power chip outputs a dynamically adjustable voltage signal instead of a PWM signal, EMI interference will not be generated through the wiring harness. Since the DCDC power chip outputs a PWM signal instead of a PWM signal, noise perceptible to the human ear will not be generated. Moreover, compared with the hardware PID adjustment method, the external controller only provides a control signal and does not participate in the PID adjustment process, so the circuit responds faster.

[0045] In some embodiments, see Figure 2 The current recovery module 120 may include: a sampling resistor 1201 and a current detection amplifier 1202 .

[0046] The sampling resistor 1201 is connected between the output end of the DCDC power chip 110 and the driven solenoid valve, so that the output current of the DCDC power chip 110 will flow through the sampling resistor 1201. When the output current flows through the sampling resistor 1201, the collected voltage value of the sampling resistor 1201 is the product of the resistance value of the sampling resistor 1201 and the output current value of the DCDC power chip 110. In this way, the output current value of the DCDC power chip 110 can be determined based on the voltage value of the sampling resistor 1201.

[0047] However, since the sampling resistor 1201 is connected in series between the output end of the DCDC power chip 110 and the driven solenoid valve, it will cause shunting. In order to reduce the power loss caused by the shunting of the sampling resistor 1201, the resistance of the sampling resistor 1201 is usually small, which makes the voltage value of the sampling resistor 1201 small and difficult to detect. Therefore, in order to facilitate the detection of the output current value, the current recovery module 120 also includes a current detection amplifier 1202 with an amplification function.

[0048] The two input terminals of the current detection amplifier 1202 are respectively connected to the two ends of the sampling resistor 1201. In this way, the voltage value at the two ends of the sampling resistor 1201 can be collected, and then the voltage difference between the two ends can be determined, and the voltage difference is the voltage value of the sampling resistor 1201. Further, the current detection amplifier 1202 amplifies the voltage value of the sampling resistor 1201 according to its gain, so as to obtain an amplified voltage value, and outputs the amplified voltage value as a first electrical signal corresponding to the output current value of the DCDC power chip 110.

[0049] The expression corresponding to the amplified voltage value is as follows:

[0050] V=G*R*I load

[0051] Wherein, V represents the output voltage value of the current detection amplifier 1202, G represents the gain of the current detection amplifier 1202, that is, the amplification factor, R represents the resistance value of the sampling resistor 1201, and I load represents the output current value of the DCDC power chip 110. In practical applications, G and R are constant values ​​set according to actual conditions. It can be seen that the output current value of the DCDC power chip 110 is positively correlated with the first electrical signal output by the current detection amplifier 1202.

[0052] The sampling resistor 1201 and the current detection amplifier 1202 can ensure that the output current value of the DCDC power chip 110 can be detected in real time.

[0053] In some embodiments, see Figure 3 The feedback voltage adjustment module 130 may include: an operational amplifier 1301, and the model of the operational amplifier 1301 may be selected according to actual conditions.

[0054] The operational amplifier 1301 includes a forward input terminal, a reverse input terminal and an output terminal, wherein the forward input terminal IN+ of the operational amplifier 1301 is connected to the output terminal of the current detection amplifier 1202 in the current recovery module 120, and is used to receive the first electrical signal output by the current detection amplifier 1202, and the reverse input terminal IN- of the operational amplifier 1301 is used to receive a second electrical signal input from the outside, and the output terminal of the operational amplifier 1301 is connected to the feedback terminal of the DCDC power chip 110.

[0055] When the first electrical signal and the second electrical signal are both voltage signals, the positive input voltage V IN+ That is, the voltage value of the first electrical signal, the voltage V at the reverse input terminal of the operational amplifier IN- is the voltage value of the second electrical signal. Based on this, the operational amplifier 1301 determines V IN+ <V IN- In the case of V, a positive feedback is output, that is, a positive feedback is superimposed on the feedback end of the DCDC power chip 110, so that the voltage of the feedback end is lower than its reference voltage, thereby increasing the output voltage of the DCDC power chip 110 and achieving the purpose of increasing the output current. IN+ >V IN- In the case of , a negative feedback is output, that is, a negative feedback is superimposed on the feedback end of the DCDC power chip 110, so that the voltage of the feedback end is higher than its reference voltage, thereby reducing the output voltage of the DCDC power chip 110, further achieving the purpose of reducing the output current. IN+ Indicates the voltage value of the positive input terminal, V IN- Indicates the voltage value of the negative input terminal.

[0056] Through the operational amplifier 1301, positive feedback or negative feedback can be superimposed on the feedback end of the DCDC power chip 110 according to the first electrical signal input by the current recovery module 120 and the second electrical signal input by the outside, thereby adjusting the output voltage of the DCDC power chip, so that the DCDC power chip outputs a driving voltage corresponding to the driving current target value.

[0057] In some embodiments, the second electrical signal may be a pulse width modulation (PWM) signal corresponding to the drive current target value and provided by an external controller. Figure 4 As shown, the feedback voltage adjustment module 130 may further include a conversion submodule 1302 in addition to the operational amplifier 1301 .

[0058] The conversion submodule 1302 is connected between the inverting input terminal of the operational amplifier 1301 and the external controller, and is used to convert the pulse width modulation signal provided by the external controller into a smooth voltage signal.

[0059] The external controller may include a microcontroller unit MCU, which calculates a duty cycle value based on a drive current target value, and then outputs a pulse width modulation PWM signal having a certain duty cycle and corresponding to the drive current target value based on the duty cycle value.

[0060] Exemplarily, when the current recovery module 120 includes a sampling resistor 1201 and a current detection amplifier 1202, the MCU may calculate the duty cycle of the PWM signal corresponding to the target driving current value in the following manner:

[0061] Since the positive input terminal IN+ of the operational amplifier 1301 is connected to the output terminal of the current recovery module 120, V IN+ =V=G*R*I load , will I load is replaced by the drive current target value, according to the virtual short characteristic V of the operational amplifier 1301 IN+ =V IN- , we can get PWM Duty=V IN- / V2, where PWM Duty indicates the duty cycle of the PWM signal and V2 indicates the operating voltage of the MCU.

[0062] The PWM signal output by the MCU is converted into a relatively stable voltage signal after passing through the conversion submodule 1302 and is sent to the inverting input terminal IN− of the operational amplifier 1301 .

[0063] In the above manner, the external controller provides a PWM signal with an adjustable duty cycle corresponding to the drive current target value to the feedback voltage adjustment module 130, so that the feedback voltage adjustment module 130 can automatically adjust the feedback voltage at the feedback end based on the PWM signal, and then the DCDC power supply chip 110 outputs an adjustable power voltage signal based on the feedback voltage at the feedback end for driving the solenoid valve.

[0064] In some embodiments, see Figure 5 , the conversion module 1302 may include an RC filter circuit. The RC filter circuit is called a resistor-capacitance circuit (English: Resistor-Capacitance circuit).

[0065] like Figure 5 As shown, the RC filter circuit includes a resistor and a capacitor, wherein one end of the resistor is connected to the reverse input end of the operational amplifier 1301, the other end of the resistor is connected to the external controller, one end of the capacitor is connected to the external controller, and the other end of the capacitor is grounded.

[0066] The parameters of the resistor and capacitor in the RC filter circuit can be set according to the period of the PWM signal and the voltage accuracy of the voltage signal to be input to the reverse input terminal of the operational amplifier 1301.

[0067] The PWM signal can be passed through an RC filtering circuit to obtain a voltage signal that is linearly related to the signal duty cycle, thereby realizing the conversion of the PWM signal to a voltage signal.

[0068] In some embodiments, see Figure 6 The solenoid valve driving circuit may further include: an anti-backflow module 610 .

[0069] like Figure 6 As shown, one end of the backflow prevention module 610 is connected to one end of the inductive load in the solenoid valve, and the other end of the backflow prevention module 610 is connected to the output end of the DCDC power chip 110, so as to prevent the reverse electromotive force generated by the inductive load in the solenoid valve from entering the DCDC power chip 110 when it is turned off.

[0070] Exemplarily, the backflow prevention module 610 may include a Schottky diode, an anode of the Schottky diode is connected to the output end of the DCDC power chip 110 , and a cathode of the Schottky diode is connected to one end of the inductive load in the solenoid valve.

[0071] In some embodiments, see Figure 7 The solenoid valve driving circuit may further include: a freewheeling module 710 .

[0072] like Figure 7 As shown, one end of the freewheeling module 710 is connected to one end of the inductive load in the solenoid valve, and the other end of the freewheeling module 710 is grounded, so as to provide a discharge path for the reverse electromotive force when the inductive load is turned off.

[0073] Exemplarily, the freewheeling module 710 may include a Schottky diode, an anode of the Schottky diode is connected to one end of the inductive load in the external load, and a cathode of the Schottky diode is grounded.

[0074] By providing the backflow prevention module 610 and / or the freewheeling module 710 , it is possible to prevent the DCDC power chip 110 from being damaged by the reverse electromotive force.

[0075] For ease of understanding, the solenoid valve driving circuit provided in the embodiment of the present application is described below by taking the application of the solenoid valve driving circuit provided in the embodiment of the present application to be applied in a vehicle to drive a solenoid valve in the vehicle as an example.

[0076] See also Figure 8 , is a schematic diagram of a solenoid valve drive circuit used in a vehicle provided in an embodiment of the present application. Figure 8As shown, it includes: a DCDC power chip 810, a current recovery module 820, a feedback voltage adjustment module 830, an anti-backflow module 840 and a freewheeling module 850.

[0077] Among them, the DCDC power chip 810 includes a step-down DCDC power chip U1. The model of U1 is selected according to the working current requirement of the load. In this embodiment, TI's LMR33630 is selected, and its input voltage range is: 3.8V~36V, output voltage range: 1V~24V, and output current: 3A. It can meet the load driving requirements within the working current of 3A. Among them, the feedback end, that is, the key reference voltage of FB, is 1V. The input end of U1 is connected to the power supply VBAT 12V of the BCM control system in the vehicle.

[0078] The current recovery module 820 includes a sampling resistor R1 and a circuit detection amplifier U2. The model of R1 is selected according to the working current requirement of the load. In this embodiment, a 0.02Ω resistor is used as an example. The model of U2 can be INA199B1, whose gain is G=50V / V. When the output current of the DCDC power chip U1 is I load When , the voltage V output by U2 is as follows:

[0079] V=50*0.02Ω*I load

[0080] The feedback voltage adjustment module 830 includes an operational amplifier U3 and an RC filter circuit composed of a resistor R2 and a capacitor C1. In this embodiment, the model of U3 is LM2904. The voltage V 2904_IN+ is the output voltage of the circuit detection amplifier U2, the voltage at the reverse input terminal V 2904_IN- It is the voltage of the PWM signal output by the external controller MCU after passing through the RC filter circuit. 2904_IN+ <V 2904_IN- When U3 outputs V 2904_OUT A positive feedback is superimposed on the FB pin of the DCDC power chip U1, so that the feedback voltage V FB Lower than its reference voltage, making the output voltage V of the DCDC power chip U1 OUT Increase, further increase the load drive current, that is, the output current I load When V 2904_IN+ >V 2904_IN- When V 2904_OUT A negative feedback is added to the FB pin of the DCDC power chip U1, so that V FB Higher than its reference voltage, the output voltage V OUT Reduce, further reduce the load drive current I loadpurpose.

[0081] The backflow prevention module 840 includes a Schottky diode D1, and the model may be PMEG6030EP-Q. When the inductive load in the solenoid valve is turned off, D1 is used to prevent the reverse electromotive force from damaging the DCDC power chip U1.

[0082] The freewheeling module 850 includes a Schottky diode D2, of which the model may be PMEG6030EP-Q. When the inductive load in the solenoid valve is turned off, D1 is used to provide a freewheeling path.

[0083] Figure 8 In the example, the inductor L1 and the resistor R3 connected in series are used to simulate the inductive load of the solenoid valve.

[0084] Below Figure 8 The functional implementation process of the solenoid valve drive circuit shown in the figure is explained as follows:

[0085] The solenoid valve driving circuit provided in the embodiment of the present application can meet the requirements of multi-speed driving current of the solenoid valve. The following is an example of a multi-speed driving current including a solenoid valve starting current of 2A and a holding current of 1A.

[0086] When the target drive current is 2A, the solenoid valve start current, and the MCU operating voltage is 5V, the MCU calculates the PWM duty cycle corresponding to the target drive current in the following manner:

[0087] V 2904_IN+ =50*0.02Ω*I load =50*0.02Ω*2A=2V

[0088] According to the virtual short characteristic of the operational amplifier therefore:

[0089]

[0090] The MCU outputs a PWM signal according to the theoretically calculated duty cycle value of 40%. After passing through the RC filter circuit in the feedback voltage adjustment module 830, it outputs a relatively stable voltage to the reverse input terminal IN- of the operational amplifier U3, that is,

[0091] The circuit detection amplifier U2 in the current recovery module 820 collects the voltage difference on the sampling resistor R1, thereby converting the current output current value of the step-down DCDC power chip U1 into a voltage signal and outputting it to the positive input terminal IN+ of the operational amplifier U3, that is, V 2904_IN+ .

[0092] When the current output current value of the step-down DCDC power chip U1 is lower than the drive current target value, that is, V2904_IN+ <V 2904_IN- When U3 outputs V 2904_OUT A positive feedback is superimposed on the FB pin of the DCDC power chip U1, so that the feedback voltage V FB Lower than its reference voltage, making the output voltage V of the DCDC power chip U1 OUT Increase, further increase the load drive current, that is, the output current I load When the current output current value of the step-down DCDC power chip U1 is higher than the drive current target value, that is, V 2904_IN+ >V 2904_IN- When V 2904_OUT A negative feedback is added to the FB pin of the DCDC power chip U1, so that V FB Higher than its reference voltage, the output voltage V OIT Reduce, further reduce the load drive current I load purpose.

[0093] After the above dynamic adjustment, the output current value is finally made equal to the drive current target value.

[0094] When the target drive current is 1A, the solenoid valve start current, and the MCU operating voltage is 5V, the MCU calculates the PWM duty cycle corresponding to the target drive current in the following manner:

[0095] V 2904_IN+ =50*0.02Ω*I load =50*0.02Ω*1A=1V

[0096] According to the virtual short characteristic of the operational amplifier therefore:

[0097]

[0098] The MCU outputs a PWM signal according to the theoretically calculated duty cycle value of 20%. After passing through the RC filter circuit in the feedback voltage adjustment module 830, it outputs a relatively stable voltage to the reverse input terminal IN- of the operational amplifier U3, that is,

[0099] The subsequent working process of the current recovery module 820 and the feedback voltage adjustment module 830 is consistent with that when the target driving current value is the solenoid valve starting current 2A, and will not be described in detail here to avoid repetition.

[0100] According to the embodiment of the present application, by adjusting the FB pin voltage of the DCDC power chip U1, the output voltage value is adjusted to further achieve the purpose of controlling the target value of the load drive current. The PID adjustment function of the load drive current is realized by the hardware circuit, which fundamentally reduces the high-power and high-frequency signal output of the BCM controller, thereby reducing the possibility of EMI interference and noise generation. Hardware PID adjustment realizes the adjustment and control of the output load drive current, reduces the delay increased by software adjustment, speeds up the response time, and drives the load to reach the target state quickly, greatly improving the customer experience.

[0101] Based on the solenoid valve driving circuit provided in the above embodiments, accordingly, the present application also provides a device having a solenoid valve driving circuit, and the device may include the solenoid valve driving circuit provided in any of the above embodiments.

[0102] Based on the solenoid valve drive circuit provided in the above embodiments, accordingly, the present application also provides a vehicle, which may include the solenoid valve drive circuit provided in any of the above embodiments.

[0103] Based on the solenoid valve driving circuit provided in the above embodiment, the present application also provides a solenoid valve driving method, see Fig. 9 The solenoid valve driving method provided in the embodiment of the present application may include the following steps S91-S93.

[0104] S91. The current recovery circuit collects the output current value of the DCDC power chip and outputs a first electrical signal corresponding to the output current value.

[0105] S92. The feedback voltage adjustment module adjusts the voltage at the feedback end of the DCDC power chip based on the first electrical signal and an externally input second electrical signal, wherein the second electrical signal is an electrical signal corresponding to the drive current target value.

[0106] The S93.DCDC power chip outputs a driving voltage signal for driving the solenoid valve based on the voltage at the feedback end.

[0107] In some embodiments, the first electrical signal and the second electrical signal are voltage signals. Based on this, the feedback voltage adjustment module may adjust the voltage of the feedback terminal of the DCDC power chip based on the first electrical signal and the externally input second electrical signal, which may include:

[0108] In determining V IN+ <V IN- In the case of V, a positive feedback is output, that is, a positive feedback is superimposed on the feedback end of the DCDC power chip, so that the voltage at the feedback end is lower than its reference voltage, thereby increasing the output voltage of the DCDC power chip and achieving the purpose of increasing the output current. IN+ >V IN-In this case, a negative feedback is output, that is, a negative feedback is superimposed on the feedback end of the DCDC power chip, so that the voltage at the feedback end is higher than its reference voltage, thereby reducing the output voltage of the DCDC power chip and further achieving the purpose of reducing the output current. IN+ Represents the first electrical signal, V IN- Represents the second electrical signal.

[0109] In some embodiments, when the first electrical signal is a voltage signal and the second electrical signal is a PWM signal provided by an external controller, before the feedback voltage adjustment module adjusts the voltage of the feedback terminal of the DCDC power chip based on the first electrical signal and the externally input second electrical signal, the feedback voltage adjustment module may further include:

[0110] The second electrical signal is converted into a smooth third voltage signal.

[0111] Correspondingly, the feedback voltage adjustment module adjusts the voltage of the feedback terminal of the DCDC power chip based on the first electrical signal and the second electrical signal input externally, which may include:

[0112] The feedback voltage adjustment module adjusts the voltage at the feedback end of the DCDC power chip based on the first electrical signal and the third voltage signal. The specific adjustment method is consistent with the adjustment method when the first electrical signal and the second electrical signal are voltage signals, and only the second electrical signal needs to be replaced by the third voltage signal.

[0113] The solenoid valve driving method provided in the embodiment of the present application can automatically adjust the output voltage of the DCDC power chip based on the second electrical signal input externally, so that the DCDC power chip outputs a driving voltage corresponding to the target value of the driving current. Since the DCDC power chip outputs a dynamically adjustable voltage signal instead of a PWM signal, EMI interference will not be generated through the wiring harness. Since the DCDC power chip outputs a PWM signal instead of a PWM signal, noise perceptible to the human ear will not be generated. Moreover, compared with the hardware PID adjustment method, the external controller only provides a control signal and does not participate in the PID adjustment process, so the circuit response is faster.

[0114] It should be clear that the present application is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known method is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present application is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present application.

[0115] The functional blocks shown in the above-described block diagram can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of the present application are programs or code segments that are used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link by a data signal carried in a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, optical fiber media, radio frequency (RF) links, etc. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.

[0116] It should also be noted that the exemplary embodiments mentioned in this application describe some methods or systems based on a series of steps or devices. However, this application is not limited to the order of the above steps, that is, the steps can be performed in the order mentioned in the embodiment, or in a different order from the embodiment, or several steps can be performed simultaneously.

[0117] Aspects of the present disclosure are described above with reference to the flowchart and / or block diagram of the method, device (system) and computer program product according to the embodiment of the present disclosure. It should be understood that each box in the flowchart and / or block diagram and the combination of each box in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine so that these instructions executed by the processor of the computer or other programmable data processing device enable the implementation of the function / action specified in one or more boxes of the flowchart and / or block diagram. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field programmable logic circuit. It can also be understood that each box in the block diagram and / or flowchart and the combination of boxes in the block diagram and / or flowchart can also be implemented by dedicated hardware that performs a specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0118] The above is only a specific implementation of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the protection scope of this application.

Claims

1. A solenoid valve drive circuit, characterized in that: include: DCDC power chip, current recovery module and feedback voltage adjustment module; The input end of the DCDC power chip is connected to an external power supply, the output end of the DCDC power chip is connected to a driven solenoid valve, and the feedback end of the DCDC power chip is connected to the output end of the feedback voltage adjustment module; The current recovery module is connected between the output end of the DCDC power chip and the solenoid valve; One input end of the feedback voltage adjustment module is connected to the output end of the current recovery module, and the other input end of the feedback voltage adjustment module is used to receive a second electrical signal input from the outside, wherein the second electrical signal is an electrical signal corresponding to the target value of the driving current; The current collection module is used to collect the output current value of the DCDC power chip and output a first electrical signal corresponding to the output current value; The feedback voltage adjustment module is used to adjust the voltage of the feedback terminal based on the first electrical signal and the second electrical signal; The DCDC power chip is used to output a driving voltage signal based on the voltage at the feedback end, and the driving voltage signal is used to drive the solenoid valve.

2. The solenoid valve driving circuit according to claim 1, characterized in that: The current recovery module includes: a sampling resistor and a current detection amplifier; The sampling resistor is connected between the output end of the DCDC power chip and the solenoid valve; The two input terminals of the current detection amplifier are respectively connected to the two terminals of the sampling resistor; The output end of the current detection amplifier is connected to the input end of the feedback voltage adjustment module.

3. The solenoid valve driving circuit according to claim 1, characterized in that: The feedback voltage adjustment module includes: an operational amplifier; The positive input terminal of the operational amplifier is connected to the output terminal of the current recovery module; The inverting input terminal of the operational amplifier is used to receive the second electrical signal input from the outside; The output terminal of the operational amplifier is connected to the feedback terminal.

4. The solenoid valve driving circuit according to claim 3, characterized in that: The second electrical signal is a pulse width modulation signal corresponding to the drive current target value and provided by an external controller, and the feedback voltage adjustment module further includes: a conversion submodule; The conversion submodule is connected between the inverting input terminal of the operational amplifier and the external controller, and is used for converting the pulse width modulation signal provided by the external controller into a smooth voltage signal.

5. The solenoid valve driving circuit according to claim 4, characterized in that: The conversion submodule includes an RC filter circuit; The RC filter circuit includes a resistor and a capacitor; One end of the resistor is connected to the inverting input end of the operational amplifier, and the other end of the resistor is connected to the external controller; One end of the capacitor is connected to an external controller, and the other end of the capacitor is grounded.

6. The solenoid valve driving circuit according to any one of claims 1 to 5, characterized in that: The solenoid valve driving circuit further includes: an anti-backflow module; One end of the backflow prevention module is connected to one end of the inductive load in the solenoid valve, and the other end of the backflow prevention module is connected to the output end of the DCDC power chip, so as to prevent the reverse electromotive force generated by the inductive load in the solenoid valve from entering the DCDC power chip when it is turned off.

7. The solenoid valve driving circuit according to claim 6, characterized in that: The solenoid valve driving circuit further includes: a freewheeling module; One end of the freewheeling module is connected to one end of the inductive load, and the other end of the freewheeling module is grounded, so as to provide a discharge path for the reverse electromotive force.

8. A solenoid valve driving method, characterized in that: The solenoid valve driving method is implemented based on the solenoid valve driving circuit according to any one of claims 1 to 7, and the method comprises: The current recovery circuit collects the output current value of the DCDC power chip and outputs a first electrical signal corresponding to the output current value; The feedback voltage adjustment module adjusts the voltage of the feedback terminal of the DCDC power chip based on the first electrical signal and a second electrical signal input externally, wherein the second electrical signal is an electrical signal corresponding to a target value of the driving current; The DCDC power chip outputs a driving voltage signal for driving the solenoid valve based on the voltage at the feedback terminal.

9. A device having a solenoid valve, characterized in that: The device comprises the solenoid valve driving circuit according to any one of claims 1 to 7.

10. A vehicle, characterized in that: The vehicle comprises the solenoid valve drive circuit according to any one of claims 1 to 7.

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