Detection circuit, circuit board and vehicle

Abstract

The utility model provides a detection circuit, a circuit board and a vehicle, the detection circuit comprises a sensor, a sampling module, a voltage following module and a comparison module, the sampling module is connected with a first end of the sensor and is used for converting a current signal output by the first end of the sensor into a first voltage signal; the first end of the voltage following module is connected with the sampling module and is used for outputting a second voltage signal to the processing module under the control of a first voltage signal input by the first end of the voltage following module; the first end of the comparison module is connected with the sampling module and is used for generating a third voltage signal according to a first voltage signal input by the first end and a reference voltage signal input by the second end and outputting the third voltage signal to the processing module; and the processing module determines the fault type of the sensor according to the second voltage signal and the third voltage signal. According to the invention, the sensor fault can be detected through a simple circuit, and the occupation of the sensor detection circuit on processing chip resources is reduced.

Description

Technical Field

[0001] The present application relates to the field of electronic circuits, and in particular to a detection circuit, a circuit board and a vehicle. Background Art

[0002] Sensors are important components on vehicles and can provide information about different positions of the vehicle to the vehicle's control system. Sensors play a very important role in vehicle detection. Whether the function of the sensor is normal affects driving safety. For driving safety, sensor fault monitoring is very important and necessary. Therefore, how to provide a simple detection circuit is a technical problem that needs to be solved urgently. Utility Model Content

[0003] The present application provides a detection circuit, a circuit board and a vehicle, which can detect sensor failures through a simple circuit and reduce the occupation of processing chip resources by the sensor detection circuit.

[0004] In a first aspect, the present application provides a detection circuit, which includes a sensor, a sampling module, a voltage following module and a comparison module, wherein the sampling module is connected to a first end of the sensor and is used to convert a current signal output by the first end of the sensor into a first voltage signal;

[0005] The first end of the voltage follower module is connected to the sampling module, and is used to output a second voltage signal to the processing module from the second end of the voltage follower module under the control of the first voltage signal input to the first end of the voltage follower module; wherein the second voltage signal has the same waveform shape, period and duty cycle as the first voltage signal;

[0006] The first end of the comparison module is connected to the sampling module, and is used to generate a third voltage signal based on the first voltage signal input to the first end of the comparison module and the reference voltage signal input to the second end of the comparison module, and the third voltage signal is output to the processing module from the third end of the comparison module; so that the processing module determines the fault type of the sensor based on the second voltage signal and the third voltage signal.

[0007] In a possible implementation, the circuit also includes a reference voltage module, a first end of the reference voltage module is connected to a first power supply, a second end of the reference voltage module is connected to a second end of the comparison module, and the reference voltage module is used to convert the voltage of the first power supply into the reference voltage signal.

[0008] In a possible implementation, the circuit further includes a power supply module, a first end of the power supply module is connected to a second power source, and a second end of the power supply module is connected to a second end of the sensor.

[0009] In a possible implementation, the sampling module includes a first resistor, a first end of the first resistor is connected to a first end of the voltage follower module, and a second end of the first resistor is grounded.

[0010] In a possible implementation, the voltage follower module includes an operational amplifier, a first end of the operational amplifier is connected to a first end of the first resistor, and a third end of the operational amplifier is connected to a second end of the operational amplifier.

[0011] In a possible implementation, the voltage follower module also includes a second resistor and a first capacitor; the first end of the second resistor is connected to the second end of the operational amplifier, the second end of the second resistor is connected to the first end of the first capacitor, the first end of the first capacitor is connected to the first pin of the processing module, and the second end of the first capacitor is grounded.

[0012] In a possible implementation, the comparison module includes a comparator, a third resistor, a fourth resistor, and a fifth resistor;

[0013] The first end of the comparator is connected to the first end of the first resistor, the second end of the comparator is connected to the first end of the third resistor, and the third end of the comparator outputs the output third voltage signal to the processing module;

[0014] The second end of the third resistor is connected to the reference voltage signal, the first end of the fourth resistor is connected to the second end of the comparator, and the second end of the fourth resistor is connected to the third end of the comparator;

[0015] A first end of the fifth resistor is connected to the third end of the comparator, and a second end of the fifth resistor is connected to the first power supply.

[0016] In a possible implementation, the reference voltage module includes a sixth resistor and a seventh resistor;

[0017] A first end of the sixth resistor is connected to the first power supply, and a second end of the sixth resistor is connected to the second end of the third resistor;

[0018] The first end of the seventh resistor is connected to the second end of the sixth resistor, and the second end of the seventh resistor is grounded.

[0019] In a possible implementation, the power supply module includes a second capacitor, a third capacitor, a first diode and an eighth resistor;

[0020] A first end of the second capacitor is connected to a second power supply, and a second end of the second capacitor is connected to a cathode of the first diode;

[0021] The anode of the first diode is connected to the second power supply;

[0022] A first end of the third capacitor is connected to the anode of the first diode, and a second end of the third capacitor is grounded;

[0023] A first end of the eighth resistor is connected to the cathode of the first diode, and a second end of the eighth resistor is connected to the second end of the sensor.

[0024] In a possible implementation manner, the circuit further includes a second diode, a cathode of the second diode is connected to the first end of the sensor, and a second end of the second diode is grounded.

[0025] In a second aspect, the present application provides a circuit board, comprising the circuit as described in the above-mentioned first aspect or any possible implementation of the first aspect.

[0026] In a third aspect, the present application provides a vehicle, comprising the circuit as described in the first aspect or any possible implementation of the first aspect; or the circuit board as described in the second aspect.

[0027] By implementing the detection circuit of the sensor provided by the present application, the complexity of the sensor detection circuit can be reduced, the space occupied by the circuit board can be reduced, the circuit reliability can be improved, and the occupation of the input and output interfaces of the fault signal processing chip can be reduced. In addition, a hysteresis comparator is used to detect the fault. If an overcurrent fault occurs in the circuit, the hysteresis comparator directly outputs a fault level signal to the processing chip, triggering the fault state, and the overcurrent fault response rate is faster. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the background technology, the drawings required for use in the embodiments of the present application or the background technology will be described below.

[0029] Figure 1 is a schematic diagram of the structure of the detection circuit provided in the embodiment of the present application;

[0030] Figure 2 is a schematic diagram of a detection circuit provided in an embodiment of the present application;

[0031] Figure 3 is a structural schematic diagram of another detection circuit provided in an embodiment of the present application;

[0032] Figure 4 It is a schematic diagram of another detection circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0034] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. 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 limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0035] It should be noted that the terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms of "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0036] Sensors are important components on vehicles. They can provide information about different positions of the vehicle to the vehicle's control system. Sensors play a very important role in vehicle detection. Whether the function of the sensor is normal affects driving safety. For driving safety, sensor fault monitoring is very important and necessary.

[0037] For example, the wheel speed sensor of a vehicle is an important component of the vehicle. The wheel speed sensor can provide real-time wheel speed signals for the vehicle's antilock brake system (ABS), so that the ABS can adjust the wheel braking torque in time according to the speed of each wheel when the vehicle brakes, to avoid the wheels from locking due to braking, resulting in the whole vehicle skidding, tail swinging and other safety accidents. Since the normal function of the wheel speed sensor affects driving safety, in order to ensure safe driving, on-vehicle monitoring of the wheel speed sensor is very necessary.

[0038] Fault detection is mainly used to detect when a sensor fails so that the system can take corresponding protection or alarm measures. Faults usually include sensor open circuit, sensor short circuit, and sensor installation problems, which lead to abnormal sensor output signals, such as signal glitches and signal frequency mutations.

[0039] join Figure 1 , Figure 1 1 is a schematic diagram of a detection circuit provided by the present application. The detection circuit includes a sensor 100, a sampling module 110, a voltage following module 120 and a comparison module 130. The sensor 100 may be a sensor of various types, which is not specifically limited in the present application embodiment. For example, the sensor 100 may be a wheel speed sensor of a vehicle, a sensor for detecting tire pressure of a vehicle, and the like.

[0040] The sensor 100 is used to generate a rectangular wave current with high and low changes when working. For example, if the sensor 100 is a wheel speed sensor, the wheel speed sensor usually generates a rectangular wave current signal of 7 mA, 14 mA or 28 mA during the process of detecting the rotation speed of the tire.

[0041] A first end of the sampling module 110 is connected to a first end of the sensor, and the sampling module 110 is used to convert a current signal output by the first end of the sensor into a first voltage signal.

[0042] The first end of the voltage following module 120 is connected to the sampling module 110, and is used to output a second voltage signal to the processing module from the second end of the voltage following module 120 under the control of the first voltage signal input to the first end of the voltage following module 120; wherein the second voltage signal has the same waveform shape, period and duty cycle as the first voltage signal, thereby following the first voltage signal output by the sampling module 110.

[0043] The first end of the comparison module 130 is connected to the sampling module 110, which is used to generate a third voltage signal according to the first voltage signal input to the first end of the comparison module 130 and the reference voltage signal input to the second end of the comparison module 130, and output the third voltage signal to the processing module from the third end of the comparison module 130.

[0044] The processing module is used to determine the fault type of the sensor 100 according to the second voltage signal and the third voltage signal. For example, the fault type of the sensor 100 is determined according to the high and low levels of the second voltage signal and the third voltage signal. If the first voltage signal is at a low level, the second voltage signal is at a low level, and the third voltage signal is at a high level, the processing module determines that the fault type of the sensor 100 is an open circuit fault; if the first voltage signal is at a high level, the second voltage signal is at a high level, and the third voltage signal is at a low level, the processing module determines that the fault type of the sensor 100 is a short circuit fault.

[0045] If the above sensor 100 is a wheel speed sensor, each wheel speed sensor corresponds to a set of the above detection circuits. The processing module can determine a wheel speed sensor that has failed based on the signals output to the processing module by multiple sets of detection circuits. For example, a vehicle has four tires. If the second voltage signals output to the processor by the detection circuits of three of the wheel speed sensors are the same, and the third voltage signals of the detection circuits of these three wheel speed sensors are also the same, and the second voltage signal and / or the third voltage signal output by the detection circuit of the fourth wheel speed sensor are different from those of the other three, then the processing module determines that the fourth wheel speed sensor has failed. It should be noted that the above detection circuit can also perform wheel speed detection for detecting the rotation speed of the tire.

[0046] In the embodiment of the present application, the sampling module 110, the voltage following module 120 and the comparison module 130 can all realize corresponding functions through a circuit composed of discrete devices. Figure 2 , Figure 2 It is a schematic diagram of a detection circuit provided in an embodiment of the present application.

[0047] like Figure 2 As shown in , the sampling module 110 includes a first resistor R1, and the voltage follower module 120 includes an operational amplifier IC1. Optionally, the voltage follower module 120 also includes a second resistor R2 and a first capacitor C1.

[0048] The comparison module 130 includes a comparator IC2 , a third resistor R3 , a fourth resistor R4 , and a fifth resistor R5 .

[0049] The first end of the first resistor R1 is connected to the first end of the sensor and the first end of the operational amplifier IC1 , and the second end of the first resistor R1 is grounded.

[0050] The second end of the operational amplifier IC1 is connected to the third end, and the second end of the operational amplifier IC1 is an output end, which is used to output a second voltage signal to the first pin IN1 of the processing module. When the voltage follower module 120 also includes a second resistor R2 and a first capacitor C1, the second resistor R2 is connected to the second end of the operational amplifier IC1, the second end of the second resistor R2 is connected to the first end of the first capacitor C1, the first end of the first capacitor C1 and the second end of the second resistor R2 are connected to the first pin IN1 of the processing module, and the second end of the first capacitor C1 is grounded. The second resistor R2 and the first capacitor C1 constitute a filtering circuit, which is used to filter the output signal of the operational amplifier IC1.

[0051] The voltage follower module 120 composed of the operational amplifier IC1 etc. has the characteristics of high input impedance and low output impedance, which is equivalent to the front-stage circuit being regarded as an open circuit and the rear-stage circuit being regarded as a constant voltage source, thereby reducing the influence of the front-stage and rear-stage circuit impedances on the output voltage.

[0052] The first end of the comparator IC2 is connected to the first end of the first resistor R1, the second end of the comparator IC2 is connected to the first end of the third resistor R3, and the third end of the comparator IC2 outputs a third voltage signal to the second pin IN2 of the processing module; the second end of the third resistor R3 is connected to the reference voltage signal; the first end of the fourth resistor R4 is connected to the second end of the comparator IC2, and the second end of the fourth resistor R4 is connected to the third end of the comparator IC2; the first end of the fifth resistor R5 is connected to the third end of the comparator IC2, and the second end of the fifth resistor R5 is connected to the first power supply Vd. The above reference voltage signal is obtained based on the input of the first power supply Vd.

[0053] The third resistor R3, the fourth resistor R4 and the comparator IC2 constitute a hysteresis comparator, and the fifth resistor R5 serves as a pull-up resistor. The first end of the comparator IC2 is the negative end of the comparator, and the second end of the comparator IC2 is the positive end of the comparator. The hysteresis comparator can be used to speed up the response speed of the comparator by adding positive feedback, and the positive feedback of the hysteresis comparator is strong, which can avoid self-oscillation caused by parasitic coupling of the circuit, avoid output fluctuations caused by interference of the signal near the threshold, and enhance the anti-interference ability of the circuit. In addition, the hysteresis comparator is used to detect overcurrent faults. If an overcurrent fault occurs in the circuit, the hysteresis comparator directly outputs a fault level signal to the processing chip to trigger the fault state, and the overcurrent fault response rate is faster.

[0054] In one possible implementation, Figure 2 As shown, the sampling module 110 further includes a fourth capacitor C4, a first end of the fourth capacitor C4 is connected to a first end of the first resistor R1, and a second end of the fourth capacitor C4 is grounded. The fourth capacitor C4 and the first resistor R1 can form a filter circuit to filter the signal output by the sensor 100.

[0055] In one possible implementation, Figure 2 As shown, the comparison module 130 further includes a fifth capacitor C5, a first end of the fifth capacitor C5 is connected to the second end of the third resistor R3, that is, the first end of the fifth capacitor C5 is connected to the reference voltage signal, and the second end of the fifth capacitor C5 is grounded. The fifth capacitor C5 is used to stabilize the reference voltage, that is, the reference voltage signal.

[0056] See also Figure 3 , Figure 3 It is a structural schematic diagram of another detection circuit provided in an embodiment of the present application. In a possible implementation, the above-mentioned detection circuit also includes a reference voltage module 140, a first end of the reference voltage module 140 is connected to the first power supply, and a second end of the reference voltage module 140 is connected to the second end of the comparison module. The reference voltage module 140 is used to convert the voltage of the first power supply into a reference voltage signal.

[0057] In a possible implementation, the circuit further includes a power supply module 150 , a first end of the power supply module 150 is connected to a second power source, and a second end of the power supply module 150 is connected to a second end of the sensor.

[0058] In the embodiment of the present application, the reference voltage module 140 and the power supply module 150 can both realize corresponding functions through a circuit composed of discrete components. Figure 4 , Figure 4 It is a schematic diagram of another detection circuit provided in an embodiment of the present application.

[0059] like Figure 4 As shown, the reference voltage module 140 includes a sixth resistor R6 and a seventh resistor R7. The first end of the sixth resistor R6 is connected to the first power source Vd, and the second end of the sixth resistor R6 is connected to the second end of the third resistor R3; the first end of the seventh resistor R7 is connected to the second end of the sixth resistor R6, and the second end of the seventh resistor R7 is grounded. The sixth resistor R6 and the seventh resistor R7 form a voltage divider circuit, which is used to divide the input voltage of the first power source Vd to obtain the above-mentioned reference voltage, that is, the reference voltage signal, and input the reference voltage signal into the comparison module 130.

[0060] The power supply module 150 includes a second capacitor C2, a third capacitor C3, a first diode D1 and an eighth resistor R8. The first end of the second capacitor C2 is connected to the second power supply Vc, and the second end of the second capacitor C2 is connected to the cathode of the first diode D1; the anode of the first diode D1 is connected to the second power supply Vc; the first end of the third capacitor C3 is connected to the anode of the first diode D1, and the second end of the third capacitor C3 is grounded; the first end of the eighth resistor R8 is connected to the cathode of the first diode D1 and the second end of the second capacitor C2, and the second end of the eighth resistor R8 is connected to the second end of the sensor.

[0061] The second capacitor C2 is a filter capacitor used to filter out interference signals; the first diode D1 prevents reverse voltage and reverse current from damaging the circuit; the third capacitor C3 is a support capacitor used to stabilize the intermediate DC voltage and provide instantaneous energy exchange; the eighth resistor R8 is a current limiting resistor that limits the maximum current in the circuit. When the power supply is connected, the power supply first stores energy through the third capacitor C3, then prevents current reverse flow through the first diode D1, and then passes through the second capacitor C2 for filtering, and after passing through the eighth resistor R8 for current limiting, a stable voltage is output to power the sensor.

[0062] The detection circuit further includes a limiting module 160, a first end of which is connected to a first end of the sensor, and a second end of which is grounded, for limiting the maximum value of the output voltage of the sensor 100. Figure 4As shown in , the limiting module 160 includes a second diode D2. The cathode of the second diode D2 is connected to the first end of the sensor 100, and the second end of the second diode D2 is grounded. In the embodiment of the present application, the second diode D2 is a transient voltage suppressor (TVS) diode, which is used to absorb transient overvoltage interference and limit the maximum voltage.

[0063] In one possible implementation, Figure 4 As shown in , the comparison module 130 also includes a ninth resistor R9 and a sixth capacitor C6. The first end of the ninth resistor R9 is connected to the third end of the comparator IC2, the second end of the ninth resistor R9 is connected to the second pin IN2 of the processing module, the first end of the sixth capacitor C6 is connected to the second end of the ninth resistor R9, and the second end of the sixth capacitor C6 is grounded. The ninth resistor R9 and the sixth capacitor C6 constitute a filtering circuit for filtering the third voltage signal output by the comparator IC2.

[0064] It should be noted that Figures 1 to 4 The circuits of each module are only examples and should not be understood as specific limitations. Each module can also achieve the same function through more or fewer discrete devices and other connection methods, and the embodiments of the present application do not make specific limitations.

[0065] The present application also provides a circuit board, the circuit board comprising Figures 1 to 4 The specific functions implemented by the circuit board can be found in the above introduction to the detection circuit, which will not be repeated here.

[0066] The embodiment of the present application also provides a vehicle, which includes the above circuit board. When the sensor is a wheel speed sensor, each tire of the vehicle has a wheel speed sensor, and each wheel speed sensor corresponds to a set of the above detection circuits.

[0067] Those of ordinary skill in the art will appreciate that the modules and method steps of each example described in conjunction with the embodiments disclosed herein can be implemented with electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0068] In the several embodiments provided in the present application, it should be understood that the disclosed circuits and methods can be implemented in other ways. For example, the embodiments described above are only schematic, for example, the division of the modules is only a logical function division, and there may be other division methods in actual implementation, such as multiple components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, or can be electrical, mechanical or other forms of connection.

[0069] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A detection circuit, characterized in that: It includes a sensor, a sampling module, a voltage follower module and a comparison module, among which: The sampling module is connected to the first end of the sensor and is used to convert the current signal output by the first end of the sensor into a first voltage signal; The first end of the voltage follower module is connected to the sampling module, and is used to output a second voltage signal to the processing module from the second end of the voltage follower module under the control of the first voltage signal input to the first end of the voltage follower module; wherein the second voltage signal has the same waveform shape, period and duty cycle as the first voltage signal; The first end of the comparison module is connected to the sampling module, and is used to generate a third voltage signal based on the first voltage signal input to the first end of the comparison module and the reference voltage signal input to the second end of the comparison module, and the third voltage signal is output to the processing module from the third end of the comparison module; so that the processing module determines the fault type of the sensor based on the second voltage signal and the third voltage signal.

2. The circuit according to claim 1, characterized in that The circuit also includes a reference voltage module, a first end of the reference voltage module is connected to a first power supply, a second end of the reference voltage module is connected to a second end of the comparison module, and the reference voltage module is used to convert the voltage of the first power supply into the reference voltage signal.

3. The circuit according to claim 2, characterized in that The circuit further comprises a power supply module, a first end of the power supply module is connected to a second power source, and a second end of the power supply module is connected to a second end of the sensor.

4. The circuit according to claim 3, characterized in that The sampling module comprises a first resistor, a first end of the first resistor is connected to a first end of the voltage follower module, and a second end of the first resistor is grounded.

5. The circuit according to claim 4, characterized in that The voltage follower module includes an operational amplifier, a first end of the operational amplifier is connected to a first end of the first resistor, and a third end of the operational amplifier is connected to a second end of the operational amplifier.

6. The circuit according to claim 5, characterized in that The voltage follower module also includes a second resistor and a first capacitor; The first end of the second resistor is connected to the second end of the operational amplifier, the second end of the second resistor is connected to the first end of the first capacitor, the first end of the first capacitor is connected to the first pin of the processing module, and the second end of the first capacitor is grounded.

7. The circuit according to any one of claims 4 to 6, characterized in that: The comparison module includes a comparator, a third resistor, a fourth resistor and a fifth resistor; The first end of the comparator is connected to the first end of the first resistor, the second end of the comparator is connected to the first end of the third resistor, and the third end of the comparator outputs the output third voltage signal to the processing module; The second end of the third resistor is connected to the reference voltage signal, the first end of the fourth resistor is connected to the second end of the comparator, and the second end of the fourth resistor is connected to the third end of the comparator; A first end of the fifth resistor is connected to the third end of the comparator, and a second end of the fifth resistor is connected to the first power supply.

8. The circuit according to claim 7, characterized in that The reference voltage module includes a sixth resistor and a seventh resistor; A first end of the sixth resistor is connected to the first power supply, and a second end of the sixth resistor is connected to the second end of the third resistor; The first end of the seventh resistor is connected to the second end of the sixth resistor, and the second end of the seventh resistor is grounded.

9. The circuit according to claim 4, characterized in that The power supply module includes a second capacitor, a third capacitor, a first diode and an eighth resistor; A first end of the second capacitor is connected to a second power supply, and a second end of the second capacitor is connected to a cathode of the first diode; The anode of the first diode is connected to the second power supply; A first end of the third capacitor is connected to the anode of the first diode, and a second end of the third capacitor is grounded; A first end of the eighth resistor is connected to the cathode of the first diode, and a second end of the eighth resistor is connected to the second end of the sensor.

10. The circuit according to claim 4, characterized in that The circuit further includes a second diode, a cathode of the second diode is connected to the first terminal of the sensor, and a second terminal of the second diode is grounded.

11. A circuit board, characterized in that: Comprising a circuit as claimed in any one of claims 1 to 10.

12. A vehicle, characterized in that: Comprising one or more circuit boards as claimed in claim 11.

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