A driving circuit, a control method and a vehicle

Abstract

The present invention discloses a driving circuit, a control method and a vehicle, wherein the circuit comprises: a driving module, a high-side circuit and a low-side circuit; the high-side circuit comprises a first switch tube; the low-side circuit comprises a second switch tube; the second end of the high-side circuit is connected to the first end of the load, and the first end of the low-side circuit is connected to the second end of the load; the driving module is connected to the first switch tube and the second switch tube, and is used to output a driving signal to the first switch tube and the second switch tube; the driving module is also used to diagnose overcurrent faults, short circuit to power supply faults, short circuit to ground faults and load open circuit faults. The driving circuit of the present invention can accurately determine the type of fault occurrence, and avoid omissions and false alarms in fault diagnosis to the greatest extent. The high-side circuit and / or the low-side circuit are turned off in time, so as to protect facilities such as loads from being damaged.

Description

Technical Field

[0001] The present invention relates to the field of automobile technology, and in particular to a drive circuit, a control method and a vehicle. Background Art

[0002] With the rapid development of electronic technology, the automotive field has become a major market for electronic applications, and the application of intelligent drives has also increased. In actual working processes, actuators generally have to withstand high power and generate high heat. Especially in fault modes such as short circuits, the heat generated is even greater, which will cause device damage and reduce the service life of the controller.

[0003] In the current controller development process, due to unclear drive diagnosis mechanism and inaccurate fault status determination scheme, there are often omissions and false alarms in the fault diagnosis of intelligent drive circuits. Especially in the high-side and low-side combined drive mode, its working state is more complicated, the factors affecting diagnosis are more diverse, and the omissions and false alarms are more prominent. Summary of the invention

[0004] The present invention provides a drive circuit, a control method and a vehicle to solve the problems of missed alarm and false alarm in drive circuit fault detection.

[0005] According to one aspect of the present invention, there is provided a driving circuit, the circuit comprising: a driving module, a high-side circuit and a low-side circuit;

[0006] The high-side circuit includes a first end and a second end, and the high-side circuit also includes a first switch tube, and the first switch tube is connected between the first end and the second end of the high-side circuit; the first end of the high-side circuit is connected to a power supply, and the second end of the high-side circuit is grounded via a first freewheeling diode;

[0007] The low-side circuit includes a first end and a second end, and the low-side circuit also includes a second switch tube, and the second switch tube is connected between the first end and the second end of the low-side circuit; the first end of the low-side circuit is connected to the power supply via the second freewheeling diode;

[0008] The second end of the high-side circuit is connected to the first end of the load, and the first end of the low-side circuit is connected to the second end of the load;

[0009] The driving module is connected to the first switch tube and the second switch tube, and is used to output a driving signal to the first switch tube and the second switch tube; the driving module is also used to diagnose an overcurrent fault, a short circuit to a power supply fault, a short circuit to a ground fault, and a load open circuit fault;

[0010] Among them, the short circuit to power supply fault and the short circuit to ground fault include: high side short circuit to ground, and low side short circuit to power supply, high side short circuit to power supply and low side short circuit to ground; high side short circuit to ground means that the high side circuit is short circuit to ground, high side short circuit to power supply means that the high side circuit is short circuit to power supply, low side short circuit to ground means that the low side circuit is short circuit to ground, and low side short circuit to power supply means that the low side circuit is short circuit to the power supply;

[0011] The overcurrent fault includes: the current of at least one of the first switch tube and the second switch tube is greater than the preset overcurrent;

[0012] The load open circuit fault includes: when the first switch tube and the second switch tube are both turned off, the first end of the load is in a suspended state and / or the second end of the load is in a suspended state.

[0013] According to another aspect of the present invention, a control method for a driving circuit is provided, the method comprising:

[0014] Control the first switch tube to turn off and the second switch tube to turn off, enter a first state in which the high side is turned off and the low side is turned off, and maintain the first state for a first preset time, diagnose a short circuit to power supply fault and a short circuit to ground fault, and determine that it is normal if there is no high side short circuit to power supply and no low side short circuit to ground;

[0015] If the first state is normal, the first switch tube is controlled to be turned off and the second switch tube is turned on, entering the second state where the high side is turned off and the low side is turned on, and the second state is maintained for a second preset time to perform load open circuit fault diagnosis;

[0016] If no fault is reported in the second state, the first switch tube is controlled to be turned on and the second switch tube is controlled to be turned on, entering the third state with the high side turned on and the low side turned on, and an overcurrent fault diagnosis is performed in the third state; when an overcurrent fault is detected, the first switch tube is controlled to be turned off and the second switch tube is turned off, and they stay in the first state for at least a third preset time; the diagnosis result is read, the overcurrent fault diagnosis is performed, and the fault type is determined by combining the two fault diagnosis results.

[0017] According to another aspect of the present invention, a vehicle is provided, comprising the drive circuit provided by the first aspect.

[0018] The technical solution of the present invention provides a driving circuit, a control method and a vehicle, wherein the driving circuit includes a high-side circuit and a low-side circuit. When both the high-side circuit and the low-side circuit are turned on, the driving module detects whether an overcurrent fault occurs in the driving circuit. When the high-side circuit and / or the low-side circuit are turned off, the driving module detects whether a load open circuit fault, a short circuit to a power supply fault and a short circuit to a ground fault occur in the driving circuit. When the driving module detects that a fault occurs in the driving circuit, the driving module controls the high-side circuit and / or the low-side circuit to be turned off. The driving circuit of the present invention can accurately determine the type of fault, and avoid omissions and false alarms in fault diagnosis to the greatest extent. The high-side circuit and / or the low-side circuit are turned off in time, thereby protecting facilities such as loads from being damaged.

[0019] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 is a schematic structural diagram of a driving circuit provided by an embodiment of the present invention;

[0022] Figure 2 is a structural schematic diagram of another driving circuit provided by an embodiment of the present invention;

[0023] Figure 3 is a structural schematic diagram of another driving circuit provided by an embodiment of the present invention;

[0024] Figure 4 is a flow chart of a control method of a driving circuit provided by an embodiment of the present invention;

[0025] Figure 5 It is a schematic diagram of the structure of a driving circuit in which the first switch tube is NMOS and only contains a high-side circuit;

[0026] Figure 6 It is a schematic diagram of the structure of a driving circuit in which the first switch tube is a PMOS and only contains a high-side circuit. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0028] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0029] Figure 1 Schematic diagram of a driving circuit provided by an embodiment of the present invention. Figure 1 As shown, the driving circuit includes: a driving module 10 , a high-side circuit 11 and a low-side circuit 12 .

[0030] The high-side circuit 11 includes a first end and a second end. The high-side circuit 11 also includes a first switch tube 110. The first switch tube 110 is connected between the first end and the second end of the high-side circuit 11. The first end of the high-side circuit 11 is connected to the power supply VBATT, and the second end of the high-side circuit 11 is grounded GND via a first freewheeling diode D1.

[0031] The low-side circuit 12 includes a first end and a second end. The low-side circuit 12 also includes a second switch tube 120. The second switch tube 120 is connected between the first end and the second end of the low-side circuit 12. The first end of the low-side circuit 12 is connected to the power supply VBATT via the second freewheeling diode D2.

[0032] The second end of the high-side circuit 11 is connected to the first end of the load 13 , and the first end of the low-side circuit 12 is connected to the second end of the load 13 .

[0033] The driving module 10 is connected to the first switch tube 110 and the second switch tube 120, and is used to output a driving signal to the first switch tube 110 and the second switch tube 120; the driving module 10 is also used to diagnose overcurrent faults, short circuit to power supply faults, short circuit to ground faults and load open circuit faults.

[0034] Among them, short circuit to power supply fault and short circuit to ground fault include: high side short circuit to ground, and low side short circuit to power supply, high side short circuit to power supply and low side short circuit to ground; high side short circuit to ground means that the high side circuit is short circuit to ground, high side short circuit to power supply means that the high side circuit is short circuit to power supply, low side short circuit to ground means that the low side circuit is short circuit to ground, and low side short circuit to power supply means that the low side circuit is short circuit to power supply.

[0035] The overcurrent fault includes: the current of at least one of the first switch tube 110 and the second switch tube 120 is greater than a preset overcurrent.

[0036] The load open circuit fault includes: when the first switch tube 110 and the second switch tube 120 are both turned off, the first end of the load 13 is in a suspended state and / or the second end of the load 13 is in a suspended state.

[0037] In this embodiment, the first switch tube 110 is a device for realizing the on-off of the high-side circuit, including but not limited to a field effect transistor, a bipolar transistor or a thyristor, etc. The second switch tube 120 is a device for realizing the on-off of the low-side circuit, including but not limited to a field effect transistor, a bipolar transistor or a thyristor, etc. The preset overcurrent current is pre-set according to the actual situation, and is used to determine whether an overcurrent fault occurs in the circuit of the load 13.

[0038] Specifically, the driving module 10 is connected to the control end of the first switch tube 110, and the driving module 10 outputs a first driving signal to the control end of the first switch tube 110 to control the on or off state of the first switch tube 110. The driving module 10 is connected to the control end of the second switch tube 120, and the driving module 10 outputs a second driving signal to the control end of the second switch tube 120 to control the on or off state of the second switch tube 120.

[0039] The first end of the first switch tube 110 is connected to the first terminal power supply VBATT of the high-side circuit 11, and the second end of the first switch tube 110 is connected to the second end of the high-side circuit 11 and grounded GND via the first freewheeling diode D1. Exemplarily, the first switch tube 110 can be an N-type metal-oxide-semiconductor (NMOS), and the gate of the first switch tube 110 is connected to the driving module 10, and the driving module 10 outputs a first driving signal to control the conduction or shutdown of the first switch tube 110. The drain of the first switch tube 110 is connected to the first terminal power supply VBATT of the high-side circuit 11, and the source of the first switch tube 110 is connected to the second end of the high-side circuit 11, and the second end of the high-side circuit 11 is grounded GND via the first freewheeling diode D1.

[0040] The first end of the second switch tube 120 is connected to the first end of the low-side circuit 12, and the first end of the low-side circuit 12 is connected to the power supply VBATT via the second freewheeling diode D2. The second end of the second switch tube 110 is connected to the second end of the low-side circuit 12 and the ground GND. Exemplarily, the second switch tube 120 can be an NMOS, and the gate of the second switch tube 120 is connected to the driving module 10, and the driving module 10 outputs a second driving signal to control the conduction or shutdown of the second switch tube 120. The drain of the second switch tube 120 is connected to the first end of the low-side circuit 12, and the first end of the low-side circuit 12 is connected to the power supply VBATT via the second freewheeling diode D2. The source of the second switch tube 110 is connected to the second end of the low-side circuit 12 and the ground GND.

[0041] The load 13 is connected between the high-side circuit 11 and the low-side circuit 12 . The second end of the high-side circuit 11 is connected to the first end of the load 13 , and the first end of the low-side circuit 12 is connected to the second end of the load 13 .

[0042] The driving circuit includes four circuit states: the first state: the high-side circuit 11 is turned off and the low-side circuit 12 is turned off, that is, the first switch tube 110 and the second switch tube 120 are both turned off, and the driving circuit is in the off state. The second end of the high-side circuit 11 has the same output voltage as the first end of the low-side circuit 12, and no current flows through the load 13 at this time, and the load 13 does not work. The second state: the high-side circuit 11 is turned off and the low-side circuit 12 is turned on, that is, the first switch tube 110 is turned off and the second switch tube 120 is turned on, and this state is a transition state. The second end of the high-side circuit 11 and the first end of the low-side circuit 12 both output a low level, and no current flows through the load 13 at this time, and the load 13 does not work. The third state: the high-side circuit 11 is turned on and the low-side circuit 12 is turned off, that is, the first switch tube 110 is turned on and the second switch tube 120 is turned off, and this state is a transition state. The second end of the high-side circuit 11 and the first end of the low-side circuit 12 both output a high level. At this time, no current flows through the load 13, and the load 13 does not work. The fourth state: the high-side circuit 11 is turned on and the low-side circuit 12 is turned on, that is, the first switch tube 110 and the second switch tube 120 are both turned on, and the drive circuit is in the on state. The second end of the high-side circuit 11 outputs a high level, and the first end of the low-side circuit 12 outputs a low level. At this time, current flows through the load 13, driving the load 13 to work.

[0043] When the driving circuit is in the first state, the second state and the third state, the driving module 10 detects the high-side circuit short circuit to ground, the high-side circuit short circuit to power supply, the low-side circuit short circuit to ground, the low-side circuit short circuit to power supply and the load open circuit fault. When the driving circuit is in the fourth state, the driving module 10 detects the overcurrent fault. When the driving module 10 detects that the driving circuit fails, the driving module 10 controls the first switch tube 110 and / or the second switch tube 120 to turn off.

[0044] The driver module 10 stores the fault detection results in the register, and all fault detection results of the driver module 10 can be read through the serial peripheral interface (SPI). The fault detection results have priorities, and the overcurrent fault has the highest priority. The high-priority fault detection results will always exist in the corresponding register until they are read. If a low-priority fault detection result is generated during this period, it will not be written. When the high-priority fault detection result is read and no new fault detection occurs, "NO diagnostic done" will be reported. However, when a new fault detection occurs, the information will be overwritten by a higher-priority fault detection result.

[0045] The technical solution of this embodiment provides a driving circuit, which includes a high-side circuit and a low-side circuit. When both the high-side circuit and the low-side circuit are turned on, the driving module detects whether an overcurrent fault occurs in the driving circuit. When the high-side circuit and / or the low-side circuit are turned off, the driving module detects whether a load open circuit fault, a short circuit to a power supply fault, and a short circuit to a ground fault occur in the driving circuit. When the driving module detects that a fault occurs in the driving circuit, the driving module controls the high-side circuit and / or the low-side circuit to turn off. The driving circuit of this embodiment can accurately determine the type of fault, and avoid omissions and false alarms in fault diagnosis to the greatest extent. And the high-side circuit and / or the low-side circuit are turned off in time, so as to protect the load and other facilities from being damaged.

[0046] Figure 2 FIG. 1 is a schematic diagram of another driving circuit provided by an embodiment of the present invention. Figure 2 As shown, optionally, the first switch tube 110 includes a first MOS tube Q1, and the second switch tube 120 includes a second MOS tube Q2.

[0047] The driving circuit also includes a first resistor R SH1 , the second resistor R G1 , the third resistor R PD1 , the fourth resistor R SH2 , the fifth resistor R G2 and the sixth resistor R PD2 The first resistor R SH1 The first end of the high-side circuit 11 is connected to the power supply VBATT, and the first resistor R SH1 The second end of the second resistor R G1 The first end of the second resistor R G1 The second end of the third resistor R PD1The first end of the third resistor R PD1 The second end of is connected to the second electrode of the first MOS transistor Q1 , and the second electrode of the first MOS transistor Q1 serves as the second end of the high-side circuit 11 .

[0048] The fourth resistor R SH2 The first end of the low-side circuit 12 is grounded to GND, and the fourth resistor R SH2 The second end of the fifth resistor R G2 The first end of the fifth resistor R G2 The second end of the sixth resistor R PD2 The first end of the sixth resistor R PD2 The second end of is connected to the first electrode of the second MOS tube Q2, and the second electrode of the second MOS tube Q2 serves as the first end of the low-side circuit 12.

[0049] Specifically, the first stage of the first MOS transistor Q1 is the first end of the first switch transistor 110, and the second stage of the first MOS transistor Q1 is the second end of the first switch transistor 110. The first stage of the second MOS transistor Q2 is the second end of the second switch transistor 120, and the second stage of the second MOS transistor Q2 is the second end of the second switch transistor 120. The gates of the first MOS transistor Q1 and the second MOS transistor Q2 correspond to the control ends of the first switch transistor 110 and the second switch transistor 120, respectively.

[0050] The first resistor R SH1 and the fourth resistor R SH2 The first resistor R is connected in series with the first MOS transistor Q1 and the second MOS transistor Q2 and the load 13. SH1 and the fourth resistor R SH2 It is used to sample the loop current of the load 13 when both the high-side circuit 11 and the low-side circuit 12 are turned on. SH1 The first end and the second end of the fourth resistor R SH2 The first end and the second end of are connected to the driving module 10 respectively. The driving module 10 monitors the current flowing through the first resistor R SH1 and the fourth resistor R SH2 The current value is obtained, and the voltage value corresponding to the current value is compared with the first preset voltage threshold value to determine whether an overcurrent fault occurs in the circuit of the load 13. The first preset voltage threshold value is preset according to the specific situation and is used to determine whether an overcurrent fault occurs in the circuit of the load 13. The first preset voltage threshold value can be set to two different voltage values, respectively corresponding to the current flowing through the first resistor R SH1 The voltage value corresponding to the current value and the voltage value flowing through the fourth resistor R SH2The current flowing through the first resistor R SH1 The voltage value corresponding to the current value is the sum of the above current value and the first resistor R SH1 The product of the resistance values. Flowing through the fourth resistor R SH2 The voltage value corresponding to the current value is the sum of the above current value and the fourth resistor R SH2 The product of the resistance values.

[0051] The gate of the first MOS tube Q1 passes through the second resistor R G1 Connected to the driving module 10, the driving module 10 outputs a first driving signal through the second resistor R G1 The second resistor R G1 The gate of the second MOS tube Q2 is connected to the gate of the first MOS tube Q1 through the fifth resistor R G2 The driving module 10 is connected to the driving module 10, and the driving module 10 outputs the second driving signal through the fifth resistor R G2 The voltage is transmitted to the gate of the second MOS transistor Q2 to control the on or off of the second MOS transistor Q2. G2 It is used to limit the gate current of the second MOS tube Q2 to prevent the gate current of the second MOS tube Q2 from being too large and damaging the second MOS tube Q2.

[0052] The third resistor R PD1 Connected between the gate and source of the first MOS transistor Q1, when the driving module 10 outputs the first driving signal to control the first MOS transistor Q1 to turn off, the first MOS transistor Q1 is turned off with a delay due to the parasitic capacitance between the gate and source of the first MOS transistor Q1. PD1 The setting of the sixth resistor R can make the parasitic capacitance between the gate and the source of the first MOS tube Q1 discharge or charge quickly, so that the first MOS tube Q1 is quickly turned off to avoid damage to the first MOS tube Q1. PD2 The sixth resistor R is connected between the gate and source of the second MOS transistor Q2. When the driving module 10 outputs the second driving signal to control the second MOS transistor Q2 to turn off, the parasitic capacitance between the gate and source of the second MOS transistor Q2 causes the second MOS transistor Q2 to be turned off with a delay. PD2 The configuration can enable the parasitic capacitance between the gate and the source of the second MOS tube Q2 to be discharged or charged quickly, so that the second MOS tube Q2 is quickly turned off, thereby avoiding damage to the second MOS tube Q2.

[0053] Figure 3 FIG. 1 is a schematic diagram of another driving circuit provided by an embodiment of the present invention. Figure 3As shown, optionally, the driving circuit further includes a first capacitor C M1 , the second capacitor C M2 , the seventh resistor R M1 and the eighth resistor R M1 .

[0054] The first capacitor C M1 and the seventh resistor R M1 After being connected in series, the first MOS tube Q1 is connected between the gate and the first electrode.

[0055] The second capacitor C M2 and the eighth resistor R M1 After being connected in series, the second MOS tube Q2 is connected between the gate and the second electrode.

[0056] Specifically, a first capacitor C is connected in series between the gate and the first electrode of the first MOS tube Q1. M1 and the seventh resistor R M1 A second capacitor C is connected in series between the gate of the second MOS tube Q2 and the first electrode. M2 and the eighth resistor R M1 The first capacitor C M1 , the second capacitor C M2 , the seventh resistor R M1 and the eighth resistor R M1 The setting can improve the electromagnetic interference (EMI) performance of the driving circuit.

[0057] Continue to refer Figure 3 Optionally, the driving circuit further includes a third capacitor C EMI1 and the fourth capacitor C EMI2 , the third capacitor C EMI1 and the fourth capacitor C EMI2 The setting can also improve the EMI performance of the driving circuit.

[0058] Figure 4 FIG. 1 is a flow chart of a control method of a driving circuit provided by an embodiment of the present invention. Figure 4 As shown, the method includes:

[0059] Step 400: Control the first switch tube to turn off and the second switch tube to turn off, enter the first state of high-side shutdown and low-side shutdown, and maintain the first preset time in the first state to diagnose short-circuit to power supply fault and short-circuit to ground fault. If there is no high-side short circuit to power supply and low-side short circuit to ground, it is determined to be normal.

[0060] In this embodiment, the first preset time is preset according to specific circumstances and is the holding time of the first state. The first preset time can be set to 20ms, 25ms, or 30ms, which is not specifically limited here.

[0061] Specifically, in the conduction mode of the high-side circuit and the low-side circuit driven normally by the driving circuit, the driving module first controls both the high-side circuit and the low-side circuit to be turned off, that is, controls the first switch tube and the second switch tube to be turned off. This state is used as the initialization state, and the initialization state is maintained for a first preset time. During the first preset time, the high-side short circuit to the power supply and the low-side short circuit to the ground fault are detected, and the second detection result is usually taken. If the driving module does not detect the high-side short circuit to the power supply and / or the low-side short circuit to the ground fault, it is considered that this initialization state is normal, otherwise it means that the load of the driving circuit has a short circuit to the power supply and / or to the ground fault.

[0062] Step 410: If the first state is normal, control the first switch tube to turn off and the second switch tube to turn on, enter the second state with the high side turned off and the low side turned on, and maintain the second state for a second preset time to perform load open circuit fault diagnosis.

[0063] In this embodiment, the second preset time is preset according to specific circumstances and is the holding time of the second state. The second preset time can be set to 30ms, 35ms, or 40ms, which is not specifically limited here.

[0064] Specifically, when there is no abnormality in the initialization state of the driving circuit, the driving module controls the high-side circuit to be turned off and the low-side circuit to be turned on, that is, controls the first switch tube to be turned off and the second switch tube to be turned on. This state is the second state and is also a transition state. The second state is maintained for a second preset time, and a load open circuit fault detection is performed within the second preset time, and the third detection result is usually taken to clear the diagnostic influence of the previous step state. If the driving module does not detect a load open circuit fault at this time, it indicates that the driving circuit can enter a normal driving state, that is, both the high-side circuit and the low-side circuit are turned on.

[0065] Step 420: If no fault is reported in the second state, the first switch tube is controlled to be turned on and the second switch tube is controlled to be turned on, entering the third state with the high side turned on and the low side turned on, and performing overcurrent fault diagnosis in the third state; when an overcurrent fault is detected, the first switch tube is controlled to be turned off and the second switch tube is turned off, and stay in the first state for at least a third preset time; read the diagnosis result, perform overcurrent fault diagnosis, and determine the fault type by combining the two fault diagnosis results.

[0066] In this embodiment, the third preset time is preset according to specific circumstances. When the driving module detects an overcurrent fault in the third state, the driving module controls the driving circuit to enter the first state. The third preset time is the time for which the first state is maintained.

[0067] Specifically, when there is no fault problem in the second state of the driving circuit, the driving module controls the high-side circuit to be turned on, and also controls the low-side circuit to be turned on, that is, controls the first switch tube to be turned on and the second switch tube to be turned on. In this state, the driving module performs overcurrent fault detection. If the driving module does not detect an overcurrent fault, the driving circuit continues to work normally. If the driving module detects an overcurrent fault, the driving module will control the driving circuit to enter the first state, that is, both the high-side circuit and the low-side circuit are turned off. Maintain the third preset time in the first state, and detect the high-side short circuit to the power supply and the low-side short circuit to the ground fault within the third preset time. In order to eliminate the influence of the overcurrent fault and the continuous current of the driving circuit on the detection result, the third detection result is usually taken. The fault type is determined by combining the two fault detection results.

[0068] Optionally, the control method of the drive circuit further includes: starting a first filtering time event during the period when the first switch tube and the second switch tube are converted from an off state to an on state, and not performing an overcurrent fault diagnosis.

[0069] In this embodiment, the first filtering time is preset according to specific circumstances, and is the time during which overcurrent fault diagnosis is not performed when the driving module controls the first switch tube and the second switch tube to switch from an off state to an on state.

[0070] Specifically, the driving module outputs a first driving signal to control the first switch tube to switch from the off state to the on state, and the driving module also outputs a second driving signal to control the second switch tube to switch from the off state to the on state. During this period, the first filtering time event is started, and the driving module does not perform overcurrent fault detection.

[0071] The driver module has two methods for overcurrent fault detection: the first method is to detect the current value flowing through the first resistor and the fourth resistor, and compare the voltage value corresponding to the current value with the first preset voltage threshold. If the voltage value is greater than the first preset voltage threshold, the driver module determines that an overcurrent fault occurs in the load circuit, otherwise it is determined that no overcurrent fault occurs. The second method is to detect the voltage V between the source and drain of the first switch tube. DS1 And the voltage V between the source and drain of the second switch tube DS2 , and V DS1 and V DS2The second preset voltage threshold is preset according to the specific situation and is used to determine whether an overcurrent fault occurs in the load circuit. The second preset voltage threshold can be set to two different voltage values, which are respectively the same as the voltage V between the source and the drain of the first switch tube. DS1 And the voltage V between the source and drain of the second switch tube DS2 Make a comparison.

[0072] The first switch tube and the second switch tube are switched from the off state to the on state, V DS1 and V DS2 The first filter time is set to avoid the V DS1 and V DS2 False positives occur before the voltage is fully established.

[0073] When the difference between the current in the first switch tube or the second switch tube and the first preset current threshold is smaller than the first comparison threshold, the second filtering time event is started, and overcurrent fault diagnosis is not performed.

[0074] In this embodiment, the first preset current threshold is pre-set and used to compare with the load circuit current to determine whether an overcurrent fault occurs in the load circuit. The first comparison threshold is pre-set according to specific circumstances and is the difference between the current flowing through the first switch tube or the second switch tube and the first preset current threshold.

[0075] Specifically, the driving module detects the current value flowing through the first switch tube or the second switch tube, and compares it with the first preset current threshold value. When the difference between the above current value and the first preset current threshold value is less than the first preset comparison threshold value, the driving module starts the second filtering time event, during which the driving module does not perform overcurrent fault detection. The setting of the second filtering time prevents the driving module from being affected by noise and making an erroneous judgment of an overcurrent fault.

[0076] After the second filtering time event ends, when the overcurrent time of the high-side circuit or the low-side circuit exceeds the event time of the third filtering time event, the first switch tube and the second switch tube are turned off.

[0077] In this embodiment, the third filtering time is preset according to specific circumstances and is used to determine whether to turn off the first switch tube and the second switch tube.

[0078] Specifically, after the second preset time event ends, the driving module starts the third filtering time event, and the driving module continues to detect the duration of the overcurrent fault. If the duration of the overcurrent fault exceeds the third filtering time, the driving module controls the first switch tube and the second switch tube to turn off to prevent damage to the first switch tube and the second switch tube.

[0079] When the output current of the driving circuit exceeds the first preset current threshold with a positive slope, the first filtering time event is stopped and the third filtering time event is started.

[0080] Specifically, the driving module detects the output current of the driving circuit, that is, the loop current of the load. If the loop current of the load continues to rise and exceeds the first preset current threshold with a positive slope, the driving module stops the first filtering time event and starts the third filtering time event. This arrangement ensures that the first switch tube and the second switch tube will not be damaged by overcurrent during the establishment time.

[0081] Optionally, the control method of the driving circuit also includes: starting a fourth filtering time event during the period when the first switch tube or the second switch tube is converted from an on state to an off state, and no fault diagnosis is performed; after the fourth filtering time event expires, comparing the output voltage of the driving circuit with an open circuit threshold and a short circuit threshold to determine whether a fault is reported.

[0082] In this embodiment, the fourth filtering time is preset according to specific circumstances, and is the time during which no fault diagnosis is performed when the driving module controls the first switch tube and / or the second switch tube to switch from the on state to the off state. The open circuit threshold and the short circuit threshold are preset according to specific circumstances, and are used to determine whether a load open circuit fault, a short circuit to the power supply, and a short circuit to the ground fault occur.

[0083] Specifically, the driving module outputs a first driving signal to control the first switch tube to switch from the on state to the off state, and the driving module also outputs a second driving signal to control the second switch tube to switch from the on state to the off state. During this period, the fourth filtering time event is started, and the driving module does not perform fault detection. The setting of the fourth filtering time event avoids the driving module from DS1 and V DS2 Making an incorrect diagnosis before it is thoroughly established.

[0084] After the fourth filtering time event ends, the driving module detects the voltage value V of the first terminal of the load. out1 and / or the voltage value V at the second end of the load out2 , and compares it with the open circuit threshold and the short circuit threshold to determine whether a load open circuit fault, a short circuit to the power supply, or a short circuit to the ground fault occurs. Exemplarily, when the first light switch is switched from the on state to the off state and the second switch continues to be in the on state, after the fourth filtering time event ends, the driver module detects the voltage value of the first terminal of the load. If the voltage value V out1 If the voltage value V out1 If the voltage value V out1If the value is greater than the open circuit threshold, the driver module determines that a high-side circuit short circuit to power supply failure occurs.

[0085] When the difference between the output voltage of the driving circuit and the short-circuit threshold is less than the second preset comparison value, the fifth filtering time event is started, and when the fifth filtering time event expires, the fourth filtering time event is reset and started.

[0086] In this embodiment, the second preset comparison value is preset according to the specific situation and is V out1 or V out2 The difference between the short-circuit threshold or the open-circuit threshold. The fifth filter time is V out1 or V out2 The time during which no fault diagnosis is performed when the difference between the short-circuit threshold value or the open-circuit threshold value is less than the second preset comparison value.

[0087] Specifically, when the high-side circuit is turned off and the low-side circuit is turned on, the driver module detects V out1 , and compared with the short-circuit threshold and the open-circuit threshold respectively. out1 When the difference between the short-circuit threshold and the open-circuit threshold is less than the second preset comparison value, the driver module starts the fifth filtering time event, and no fault detection is performed during this period. When the high-side circuit is turned on and the low-side circuit is turned off, the driver module detects V out2 , and compared with the short-circuit threshold and the open-circuit threshold respectively. out2 When the difference between the short-circuit threshold and the open-circuit threshold is less than the second preset comparison value, the driver module starts the fifth filtering time event, and no fault detection is performed during this period. When the high-side circuit is turned off and the low-side circuit is turned off, the driver module detects V out1 and V out2 , and compared with the short-circuit threshold and the open-circuit threshold respectively. out1 and / or V out2 When the difference between the short-circuit threshold and the open-circuit threshold is less than the second preset comparison value, the driver module starts the fifth filtering time event, and no fault detection is performed during this period. The setting of the fifth preset time avoids the influence of noise on the driver module fault diagnosis.

[0088] Optionally, the control method of the driving circuit further includes: the diagnosis step of the high side short circuit to the power supply and the low side short circuit to the ground includes:

[0089] When the first switch tube is turned off and the second switch tube is turned off stably, it is determined whether to report a high side short circuit to power supply fault and whether to report a low side short circuit to ground fault according to the voltage at the second end of the high side circuit.

[0090] Specifically, the driving module controls the first switch tube and the second switch tube to be turned off, and when the first switch tube is turned off and the second switch tube is turned off stably, the driving module detects the voltage of the second end of the high-side circuit, that is, the voltage value V of the first end of the load. out1 , if V out1 Output high level, the driver module determines that the high-side circuit is short-circuited to the power supply, and does not report the low-side circuit is short-circuited to the ground. out1 If the output is low level, the driver module determines that a short circuit occurs to the ground in the low-side circuit, and does not report a short circuit occurs to the power supply in the high-side circuit.

[0091] When the first switch tube is turned off and the second switch tube is turned on in a stable state, it is determined whether to report a high side short circuit to power supply fault based on the voltage at the second end of the high side circuit, and no low side short circuit to ground fault diagnosis is performed.

[0092] Specifically, the driving module controls the first switch tube to turn off and the second switch tube to turn on, and only detects the high-side short-circuit fault of the power supply. out1 If the output is high level, the driver module determines that the high-side circuit is short-circuited to the power supply.

[0093] When the state in which the first switch tube is turned on and the second switch tube is turned off is stable, the fault diagnosis of the high side short circuit to the power supply is not performed to determine whether the fault of the low side short circuit to the ground is reported.

[0094] Specifically, the driving module controls the first switch tube to be turned on and the second switch tube to be turned off, and only the low-side short-circuit fault is detected. At this time, the driving module detects the voltage value V out2 , if V out2 If the output is low level, the driver module determines that a short circuit occurs to the ground in the low-side circuit.

[0095] When the state in which the first switch tube is turned on and the second switch tube is turned on is stable, it is determined whether an overcurrent fault is reported.

[0096] Specifically, the driving module controls the first switch tube to be turned on and the second switch tube to be turned on. At this time, the driving module only detects the overcurrent fault.

[0097] Optionally, the control method of the driving circuit further includes: the diagnosis step of the high side short circuit to ground and the low side short circuit to power supply includes:

[0098] When the first switch tube is turned off and the second switch tube is turned off in a stable state, if the high-side circuit is short-circuited to the ground and the low-side circuit is short-circuited to the power supply, no fault will be reported.

[0099] Specifically, the driving module controls the first switch tube and the second switch tube to be turned off, and when the first switch tube is turned off and the second switch tube is turned off stably, the driving module detects the voltage of the second end of the high-side circuit, that is, the voltage value V of the first end of the load. out1 , if V out1 If the output is high level, the driver module determines that the high-side circuit is short-circuited to the power supply, and does not report a low-side circuit fault. out1 If the output is low level, the driver module determines that the low-side circuit is short-circuited to the ground and does not report a high-side circuit fault.

[0100] When the first switch tube is turned off and the second switch tube is turned on in a stable state, if the high-side circuit is short-circuited to the ground, no fault will be reported; if the low-side circuit is short-circuited to the power supply, the low-side circuit reports an overcurrent fault, and the high-side circuit then reports a short-circuit to the power supply fault.

[0101] Specifically, the driving module controls the first switch tube to turn off and the second switch tube to turn on, and the driving module will not detect and determine whether the high-side circuit is short-circuited to the ground at this time. However, if a low-side circuit short-circuit to the power supply occurs, the driving module will determine that an overcurrent fault occurs in the low-side circuit, and then determine that a high-side circuit short-circuit to the power supply occurs.

[0102] When the state of the first switch tube being turned on and the second switch tube being turned off is stable, if the high-side circuit is short-circuited to the ground, the high-side circuit reports an overcurrent fault and the low-side circuit reports a short-circuit to the ground fault; if the low-side circuit is short-circuited to the power supply, no fault will be reported.

[0103] Specifically, the driving module controls the first switch tube to be turned on and the second switch tube to be turned off, and the driving module will not detect and determine whether the low-side circuit is short-circuited to the power supply at this time. If a high-side circuit short-circuit to ground fault occurs, the driving module will determine that an overcurrent fault occurs in the high-side circuit, and then determine that a low-side circuit short-circuit to ground fault occurs.

[0104] When the state in which the first switch tube is turned on and the second switch tube is turned on is stable, it is determined whether an overcurrent fault is reported.

[0105] Specifically, the driving module controls the first switch tube to be turned on and the second switch tube to be turned on. At this time, the driving module only detects the overcurrent fault.

[0106] Optionally, the control method of the driving circuit further includes: a step of diagnosing an open circuit of the load includes:

[0107] When the state in which the first switch tube is turned off and the second switch tube is turned off is stable, both the high-side circuit and the low-side circuit perform load open circuit fault diagnosis.

[0108] Specifically, the driving module controls the first switch tube to turn off and the second switch tube to turn off, and when the state of the first switch tube being turned off and the second switch tube being turned off is stable, both the high-side circuit and the low-side circuit will perform load open circuit fault detection. The driving module detects the first terminal voltage value V out1 If the voltage value of the first terminal of the load is V out1 If the voltage V at the second end of the load is greater than the short-circuit threshold and less than the open-circuit threshold, the driver module determines that a load open-circuit fault occurs in the high-side circuit. out2 If the voltage value of the second terminal of the load is V out2 If the value is greater than the short-circuit threshold and less than the open-circuit threshold, the driver module determines that a load open-circuit fault occurs in the low-side circuit.

[0109] When the state in which the first switch tube is turned off and the second switch tube is turned on is stable, the low-side circuit does not perform a load open circuit fault diagnosis.

[0110] The driver module controls the first switch tube to turn off and the second switch tube to turn on. At this time, the low-side circuit is in the on state, so the driver module does not perform load open circuit fault detection on the low-side circuit. The driver module detects the voltage value V at the first end of the load out1 If the voltage value of the first terminal of the load is V out1 If the value is greater than the short-circuit threshold and less than the open-circuit threshold, the driver module determines that a load open-circuit fault occurs in the high-side circuit.

[0111] When the state in which the first switch tube is turned on and the second switch tube is turned off is stable, the high-side circuit does not perform a load open circuit fault diagnosis.

[0112] The driver module controls the first switch tube to turn on and the second switch tube to turn off. At this time, the high-side circuit is in the on state, so the driver module does not perform load open circuit fault detection on the high-side circuit. The driver module detects the voltage value V at the second end of the load out2 If the voltage value of the second terminal of the load is V out2 If the value is greater than the short-circuit threshold and less than the open-circuit threshold, the driver module determines that a load open-circuit fault occurs in the low-side circuit.

[0113] When the first switch tube is turned on and the second switch tube is turned on in a stable state, neither the high-side circuit nor the low-side circuit performs a load open circuit fault diagnosis.

[0114] The driving module controls the first switch tube to be turned on and the second switch tube to be turned on. At this time, both the high-side circuit and the low-side circuit are in the on state, so the driving module does not perform load open circuit fault detection on the high-side circuit and the low-side circuit.

[0115] Optionally, the control method of the driving circuit provided by the invention is also applicable to a driving circuit that only contains a high-side circuit or a low-side circuit. Figure 5It is a schematic diagram of the structure of a driving circuit in which the first switch tube is NMOS and only contains a high-side circuit. Figure 6 The present invention is a schematic diagram of a driving circuit having a PMOS first switch tube and only a high-side circuit. The driving circuit having only a high-side circuit or a low-side circuit can execute the control method of the driving circuit provided by any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0116] An embodiment of the present invention provides a vehicle, which includes the driving circuit provided by any of the above embodiments and has the beneficial effects of the driving circuit of any of the above embodiments of the present invention.

[0117] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0118] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A control method for a driving circuit, characterized in that: The driving circuit includes: a driving module, a high-side circuit and a low-side circuit; The high-side circuit includes a first end and a second end, and the high-side circuit also includes a first switch tube, and the first switch tube is connected between the first end and the second end of the high-side circuit; the first end of the high-side circuit is connected to a power supply, and the second end of the high-side circuit is grounded via a first freewheeling diode; The low-side circuit includes a first end and a second end, and the low-side circuit also includes a second switch tube, and the second switch tube is connected between the first end and the second end of the low-side circuit; the first end of the low-side circuit is connected to the power supply via a second freewheeling diode; The second end of the high-side circuit is connected to the first end of the load, and the first end of the low-side circuit is connected to the second end of the load; The driving module is connected to the first switch tube and the second switch tube, and is used to output a driving signal to the first switch tube and the second switch tube; the driving module is also used to diagnose an overcurrent fault, a short circuit to a power supply fault, a short circuit to a ground fault, and a load open circuit fault; Wherein, the short circuit to power supply fault and the short circuit to ground fault include: high side short circuit to ground, and low side short circuit to power supply, high side short circuit to power supply and low side short circuit to ground; the high side short circuit to ground means that the high side circuit is short circuit to ground, the high side short circuit to power supply means that the high side circuit is short circuit to the power supply, the low side short circuit to ground means that the low side circuit is short circuit to ground, and the low side short circuit to power supply means that the low side circuit is short circuit to the power supply; The overcurrent fault includes: the current of at least one of the first switch tube and the second switch tube is greater than the preset overcurrent; The load open circuit fault includes: when the first switch tube and the second switch tube are both turned off, the first end of the load is in a suspended state and / or the second end of the load is in a suspended state; The control method of the driving circuit comprises: Control the first switch tube to be turned off and the second switch tube to be turned off, enter a first state in which the high side is turned off and the low side is turned off, and maintain the first state for a first preset time, diagnose the short circuit to power supply fault and the short circuit to ground fault, and determine that it is normal if there is no high side short circuit to power supply and low side short circuit to ground; If the first state is normal, the first switch tube is controlled to be turned off and the second switch tube is controlled to be turned on, entering a second state where the high side is turned off and the low side is turned on, and the second state is maintained for a second preset time to perform the load open circuit fault diagnosis; If no fault is reported in the second state, the first switch tube is controlled to be turned on and the second switch tube is controlled to be turned on, entering the third state with the high side turned on and the low side turned on, and the overcurrent fault diagnosis is performed in the third state; when an overcurrent fault is detected, the first switch tube is controlled to be turned off and the second switch tube is turned off, and they stay in the first state for at least a third preset time; the diagnosis result is read, the overcurrent fault diagnosis is performed, and the fault type is determined by combining the two fault diagnosis results.

2. The control method of the driving circuit according to claim 1, characterized in that: The first switch tube includes a first MOS tube, and the second switch tube includes a second MOS tube; The driving circuit further includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor and a sixth resistor; the first end of the first resistor is connected to the power supply as the first end of the high-side circuit, the second end of the first resistor is connected to the first electrode of the first MOS tube, the first end of the second resistor is connected to the driving module, the second end of the second resistor is connected to the gate of the first MOS tube, the first end of the third resistor is connected to the gate of the first MOS tube, the second end of the third resistor is connected to the second electrode of the first MOS tube, and the second electrode of the first MOS tube serves as the second end of the high-side circuit; The first end of the fourth resistor is grounded as the second end of the low-side circuit, the second end of the fourth resistor is connected to the first electrode of the second MOS tube, the first end of the fifth resistor is connected to the driving module, the second end of the fifth resistor is connected to the gate of the second MOS tube, the first end of the sixth resistor is connected to the gate of the second MOS tube, the second end of the sixth resistor is connected to the first electrode of the second MOS tube, and the second electrode of the second MOS tube serves as the first end of the low-side circuit.

3. The control method of the driving circuit according to claim 2, characterized in that: The driving circuit further includes a first capacitor, a second capacitor, a seventh resistor and an eighth resistor; The first capacitor and the seventh resistor are connected in series and connected between the gate and the first electrode of the first MOS tube; The second capacitor and the eighth resistor are connected in series and connected between the gate and the second electrode of the second MOS tube.

4. The control method of the driving circuit according to claim 1, characterized in that: Also includes: During the period when the first switch tube and the second switch tube are switched from the off state to the on state, a first filtering time event is initiated, and the overcurrent fault diagnosis is not performed; When the difference between the current in the first switch tube or the second switch tube and the first preset current threshold is less than the first comparison threshold, a second filtering time event is initiated without performing overcurrent fault diagnosis; After the second filtering time event ends, when the overcurrent time of the high-side circuit or the low-side circuit exceeds the event time of the third filtering time event, turning off the first switch tube and the second switch tube; When the output current of the driving circuit exceeds the first preset current threshold with a positive slope, the first filtering time event is stopped and the third filtering time event is started.

5. The control method of the driving circuit according to claim 1, characterized in that: Also includes: During the period when the first switch tube or the second switch tube is switched from the on state to the off state, a fourth filtering time event is started without performing a fault diagnosis; After the fourth filtering time event expires, comparing the output voltage of the driving circuit with an open circuit threshold and a short circuit threshold to determine whether a fault is reported; When the difference between the output voltage of the driving circuit and the short-circuit threshold is less than a second preset comparison value, a fifth filter time event is started, and when the fifth filter time event expires, the fourth filter time event is reset and started.

6. The control method of the driving circuit according to claim 1, characterized in that: The steps of diagnosing the short circuit of the high side to the power supply and the short circuit of the low side to the ground include: When the first switch tube is turned off and the second switch tube is turned off in a stable state, determining whether to report a high-side short-circuit to power supply fault and determining whether to report a low-side short-circuit to ground fault according to the voltage at the second end of the high-side circuit; When the first switch tube is turned off and the second switch tube is turned on and the state is stable, determining whether to report a high-side short-circuit to power supply fault according to the voltage at the second end of the high-side circuit, and not performing a low-side short-circuit to ground fault diagnosis; When the state in which the first switch tube is turned on and the second switch tube is turned off is stable, the fault diagnosis of the high side short circuit to the power supply is not performed, and it is determined whether to report the fault of the low side short circuit to the ground; When the first switch tube is turned on and the second switch tube is turned on in a stable state, it is determined whether an overcurrent fault is reported.

7. The control method of the driving circuit according to claim 1, characterized in that: The steps of diagnosing the short circuit of the high side to the ground and the short circuit of the low side to the power supply include: When the first switch tube is turned off and the second switch tube is turned off stably, if the high-side circuit is short-circuited to the ground and the low-side circuit is short-circuited to the power supply, no fault will be reported; When the first switch tube is turned off and the second switch tube is turned on in a stable state, if the high-side circuit is short-circuited to the ground, no fault will be reported; if the low-side circuit is short-circuited to the power supply, the low-side circuit reports an overcurrent fault, and the high-side circuit subsequently reports a short-circuit to the power supply fault; When the first switch tube is turned on and the second switch tube is turned off and the state is stable, if the high-side circuit is short-circuited to the ground, the high-side circuit reports an overcurrent fault, and the low-side circuit reports a short-circuit to the ground fault; if the low-side circuit is short-circuited to the power supply, no fault will be reported; When the first switch tube is turned on and the second switch tube is turned on in a stable state, it is determined whether an overcurrent fault is reported.

8. The control method of the driving circuit according to claim 1, characterized in that: The diagnostic steps for an open load include: When the first switch tube is turned off and the second switch tube is turned off and the state is stable, both the high-side circuit and the low-side circuit perform load open circuit fault diagnosis; When the state in which the first switch tube is turned off and the second switch tube is turned on is stable, the low-side circuit does not diagnose the load open circuit fault; When the state in which the first switch tube is turned on and the second switch tube is turned off is stable, the high-side circuit does not diagnose the load open circuit fault; When the first switch tube is turned on and the second switch tube is turned on in a stable state, neither the high-side circuit nor the low-side circuit performs a load open circuit fault diagnosis.

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