Signal processing circuit, system and mobile carrier

Abstract

The embodiment of the invention provides a signal processing circuit, a signal processing system and a mobile carrier, which can be particularly used for processing signals of a wheel speed sensor. The signal processing circuit comprises a signal screening circuit, and the signal screening circuit comprises a first comparison element, a second comparison element and a first switch assembly. The first comparison element is used for outputting a first signal larger than a first threshold value, the second comparison element is used for outputting a second signal larger than a second threshold value, and the first signal and the second signal are effective signals of the WSS. When the first signal and the second signal are both output, the first switch assembly is used for outputting effective signals corresponding to two current values in the first signal and the second signal from the first output end and the second output end of the signal screening circuit respectively. Therefore, the circuit is simple, the cost is low, and effective signals with different current values can be screened and output according to wheel speed signals under different protocols.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of electronic technology, and in particular, to a signal processing circuit, system and mobile carrier. Background Art

[0002] With the development of vehicle intelligence, accurate sensor signal information is an important factor in ensuring vehicle control reliability. In intelligent braking systems and intelligent steering systems, obtaining accurate wheel speed signal information from wheel speed sensors (WSS) is a prerequisite for ensuring reliable vehicle control.

[0003] At present, the solution of processing the wheel speed signal of WSS through integrated chips has many disadvantages, including many restrictions on application scenarios, poor application flexibility and high cost. The solution of processing the wheel speed signal of WSS by building analog circuits at the board level can only support the recognition of wheel speed signals under standard protocols and pulse width modulation (PWM) protocols. Summary of the invention

[0004] The embodiments of the present application provide a signal processing circuit, system and mobile carrier, which can filter effective signals of wheel speed sensors under different protocols.

[0005] In a first aspect, a signal processing circuit 400 is provided, comprising: a signal filtering circuit 200, wherein the signal filtering circuit 200 comprises a first comparison element 210, a second comparison element 220 and a first switch component 250. The first comparison element 210 is used to output a first signal greater than a first threshold value, and the second comparison element 220 is used to output a second signal greater than a second threshold value, and the first signal and the second signal are both valid signals of a wheel speed sensor WSS. When both the first signal and the second signal are output, the first switch component 250 is used to output valid signals corresponding to two current values ​​in the first signal and the second signal from the first output terminal and the second output terminal of the signal filtering circuit 200, respectively.

[0006] In the above technical solution, through the analog circuit of multiple comparison elements and the first switch component, not only the circuit is simple and the cost is low, but also the effective signals of different current values ​​can be screened and output for wheel speed signals under different protocols. For example, for wheel speed signals under PWM protocol and standard protocol, the effective signal of the wheel speed sensor can be directly output through a comparison element. For another example, for wheel speed signals under complex AK protocol, the switch component can be used to screen out effective signals with different current values ​​and output them from two output terminals.

[0007] In combination with the first aspect, in some implementations of the first aspect, the first input terminal of the first comparison element 210 is connected to the first WSS signal input terminal, and the second input terminal of the second comparison element 220 is connected to the first WSS signal input terminal, wherein the first input terminal and the second input terminal have the same direction. The third input terminal of the first comparison element 210 is connected to the first reference voltage input terminal, and the fourth input terminal of the second comparison element 220 is connected to the second reference voltage input terminal, wherein the third input terminal and the fourth input terminal have the same direction, the third input terminal and the first input terminal have different directions, and the reference voltages of the first reference voltage input terminal and the second reference voltage input terminal are different. The output terminal 215 of the first comparison element 210 is connected to the first output terminal, and the output terminal 225 of the second comparison element 220 is connected to the second output terminal. The first switch component 250 is connected between the output terminal 215 of the first comparison element 210 and the output terminal 225 of the second comparison element 220.

[0008] In combination with the first aspect, in some implementations of the first aspect, the first switch component 250 includes a first switch 251, a first end of the first switch 251 is connected to the first output end, and a third end of the first switch 251 is connected to the second output end.

[0009] The first switch may be a transistor, for example, a field effect transistor, a triode, etc.

[0010] In some embodiments, the first switch 251 may be a field effect transistor.

[0011] In the above technical solution, the field effect transistor is a metal-oxide-semiconductor field effect transistor, and the voltage-controlled device can reduce power consumption.

[0012] In combination with the first aspect, in some implementations of the first aspect, the first switch component 250 also includes a first capacitor 252 and a first resistor 253, and the first capacitor 252 and the first resistor 253 are connected in parallel between the third end of the first switch 251 and the second end of the first switch 251.

[0013] The first capacitor 252 is used to adjust the driving speed of the first switch 251 , and the first resistor 253 is used to prevent the first switch 251 from switching on or off incorrectly and to accelerate the shutdown.

[0014] In combination with the first aspect, in certain implementations of the first aspect, the signal filtering circuit 200 also includes a second resistor 230 and a third resistor 240, wherein the second resistor 230 is connected between the output terminal 215 of the first comparison element 210 and the first end of the first switch 251; the third resistor 240 is connected between the output terminal 225 of the second comparison element 220 and the third end of the first switch 251.

[0015] Among them, the second resistor 230 is used to adjust the current waveform of the output signal of the first comparison element 210, thereby limiting the output current to prevent output short circuit failure, and the third resistor 240 is used to adjust the current waveform of the output signal of the second comparison element 220, thereby limiting the output current to prevent short circuit failure.

[0016] In combination with the first aspect, in certain implementations of the first aspect, the signal filtering circuit 200 also includes a first circuit 260, which is used to stabilize the power supply voltage. The first circuit 260 is connected between the power supply input terminal and the ground terminal, the power supply terminal 213 of the first comparison element 210 is connected to the power supply input terminal, and the power supply terminal 223 of the second comparison element 220 is connected to the power supply input terminal.

[0017] In combination with the first aspect, in certain implementations of the first aspect, the signal filtering circuit 200 also includes a first voltage divider circuit 270, which is used to convert the reference voltage signal into a first reference voltage signal and a second reference voltage signal, which are input into the first reference voltage input terminal and the second reference voltage input terminal, respectively.

[0018] In the above technical solution, two reference voltage signals with different voltage values ​​can be output through the voltage divider circuit, which can reduce the number of reference voltage input terminals.

[0019] In combination with the first aspect, in some implementations of the first aspect, the signal processing circuit 400 further includes a fault detection circuit 300, and the fault detection circuit 300 includes a third comparison element 310, a fourth comparison element 320, a second switch component 330, and a third switch component 340. The third comparison element 310 is used to output a third signal less than a third threshold value, and the fourth comparison element 320 is used to output a fourth signal greater than a fourth threshold value. When both the third signal and the fourth signal are output, the second switch component 330 and the third switch component 340 are used to control the fault signal to be output from the third output terminal, and control the fault current of the fault signal to be greater than the fourth threshold value, and the fault current to be less than the third threshold value.

[0020] In the above technical solution, the state of the wheel speed sensor can be judged through multiple switch components and multiple comparison elements. When the wheel speed sensor is abnormal, a fault signal can be output to facilitate subsequent timely processing of the fault signal, thereby improving the reliability of the wheel speed sensor.

[0021] In combination with the first aspect, in some implementations of the first aspect, the fifth input terminal of the third comparison element 310 is connected to the first WSS signal input terminal, and the sixth input terminal of the fourth comparison element 320 is connected to the first WSS signal input terminal, wherein the fifth input terminal and the sixth input terminal have different directions. The seventh input terminal of the third comparison element 310 is connected to the third reference voltage input terminal, and the eighth input terminal of the fourth comparison element 320 is connected to the fourth reference voltage input terminal, wherein the seventh input terminal and the eighth input terminal have different directions, the fifth input terminal and the seventh input terminal have different directions, and the reference voltages of the third reference voltage input terminal and the fourth reference voltage input terminal are different. The second switch component 330 connects the output terminal 315 of the third comparison element 310 and the third output terminal, and the third switch component 340 connects the output terminal 325 of the fourth comparison element 320 and the second switch component 330.

[0022] In combination with the first aspect, in some implementations of the first aspect, the fault detection circuit 300 also includes a second circuit 350, which is used for filtering, stabilizing voltage and limiting output signal current, and the second circuit 350 is connected between the third output terminal and the ground terminal.

[0023] In combination with the first aspect, in certain implementations of the first aspect, the fault detection circuit 300 also includes a third circuit 360, which is used to stabilize the power supply voltage. The third circuit 360 is connected between the power input terminal and the ground terminal, the power terminal 313 of the third comparison element 310 is connected to the power input terminal, and the power terminal 323 of the fourth comparison element 320 is connected to the power input terminal.

[0024] In combination with the first aspect, in certain implementations of the first aspect, the fault detection circuit 300 also includes a twelfth resistor 371 and a thirteenth resistor 372, the twelfth resistor 371 is connected between the output terminal 315 of the third comparison element 310 and the first end of the second switch 331 of the second switch component 330, and the thirteenth resistor 372 is connected between the third end of the third switch 341 of the third switch component 340 and the output terminal 325 of the fourth comparison element 320.

[0025] Among them, the twelfth resistor 371 is used to adjust the current waveform of the output signal of the third comparison element 310, thereby limiting the output current to prevent output short circuit failure, and the thirteenth resistor 372 is used to adjust the current waveform of the output signal of the fourth comparison element 320, thereby limiting the output current to prevent output short circuit failure.

[0026] In combination with the first aspect, in certain implementations of the first aspect, the fault detection circuit 300 also includes a second voltage divider circuit 390, which is used to convert the reference voltage signal into a third reference voltage signal and a fourth reference voltage signal, which are input into the third reference voltage input terminal and the fourth reference voltage input terminal, respectively.

[0027] In the above technical solution, two reference voltage signals with different voltage values ​​can be output through the voltage divider circuit, which can reduce the number of reference voltage input terminals.

[0028] In combination with the first aspect, in some implementations of the first aspect, the signal processing circuit 400 further includes a sampling filter circuit 410, and the sampling filter circuit 410 is used to filter out high-frequency noise of the WSS signal output by the wheel speed sensor.

[0029] In combination with the first aspect, in some implementations of the first aspect, the second WSS signal input terminal of the sampling and filtering circuit 410 is connected to the wheel speed sensor, and the first WSS signal output terminal of the sampling and filtering circuit 410 is connected to the first WSS signal input terminal.

[0030] In combination with the first aspect, in certain implementations of the first aspect, the signal processing circuit 400 also includes a current-voltage conversion element 430, which is used to convert the current signal of the WSS after filtering out the high-frequency noise into a voltage signal of the WSS, and the current-voltage conversion element 430 is connected between the first WSS signal output terminal and the ground terminal.

[0031] In combination with the first aspect, in some implementations of the first aspect, the signal processing circuit 400 further includes a power supply circuit 420, and the power supply circuit 420 is used to supply power to the wheel speed sensor.

[0032] In a second aspect, a wheel speed sensor is provided, characterized in that the wheel speed sensor comprises the signal processing circuit 400 in the first aspect and any one of the implementations of the first aspect.

[0033] In a third aspect, a signal processing system is provided, characterized in that the signal processing system includes a wheel speed sensor, a processor and a signal processing circuit 400 of the first aspect and any implementation of the first aspect, and the signal processing circuit 400 is connected between the wheel speed sensor and the processor.

[0034] In a fourth aspect, a mobile carrier is provided, characterized in that the mobile carrier includes the signal processing circuit 400 of the first aspect and any implementation of the first aspect, or the mobile carrier includes the wheel speed sensor of the second aspect, or the mobile carrier includes the signal processing system of the third aspect.

[0035] It should be understood that the mobile carrier in the present application may include road vehicles, water vehicles, air vehicles, industrial equipment, agricultural equipment, or entertainment equipment, etc. For example, the mobile carrier may be a vehicle, which is a vehicle in a broad sense, and may be a vehicle (such as a commercial vehicle, a passenger car, a motorcycle, a flying car, a train, etc.), an industrial vehicle (such as a forklift, a trailer, a tractor, etc.), an engineering vehicle (such as an excavator, a bulldozer, a crane, etc.), agricultural equipment (such as a lawn mower, a harvester, etc.), amusement equipment, a toy vehicle, etc. The embodiment of the present application does not specifically limit the type of vehicle. For another example, the mobile carrier may be a vehicle such as an airplane or a ship.

[0036] In combination with the fourth aspect, in certain implementations of the fourth aspect, the mobile carrier is a vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a schematic diagram of a WSS signal processing system provided by an embodiment of the present application;

[0038] Figure 2 It is a schematic diagram of a signal screening circuit in a signal processing circuit provided in an embodiment of the present application;

[0039] Figure 3 is a schematic diagram of another signal screening circuit in the signal processing circuit provided in an embodiment of the present application;

[0040] Figure 4 is a schematic diagram of a fault detection circuit in a signal processing circuit provided in an embodiment of the present application;

[0041] Figure 5 is a schematic diagram of another fault detection circuit in the signal processing circuit provided in an embodiment of the present application;

[0042] Figure 6 is a schematic diagram of a sampling filter circuit of a signal processing circuit provided in an embodiment of the present application;

[0043] Figure 7 It is a system schematic diagram of a signal processing circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0045] Figure 1 It is a schematic diagram of a WSS signal processing system provided in an embodiment of the present application.

[0046] like Figure 1As shown in (a), a signal processing system of a WSS includes a wheel speed sensor 110, an integrated chip 120 and a microcontroller (MCU) 130. The integrated chip 120 includes a voltage regulating module 121 and a decoding module 122. The wheel speed signal output by the wheel speed sensor 110 is input to the integrated chip 120 for decoding, and the decoded signal is input to the MCU 130.

[0047] The above solution can effectively process wheel speed signals, but it has disadvantages such as many restrictions on application scenarios, poor application flexibility and high cost.

[0048] like Figure 1 As shown in (b), another signal processing system of WSS includes a wheel speed sensor 110, an analog circuit 140 and a microprocessor 130. The wheel speed signal output by the wheel speed sensor 110 is input to the analog circuit 140 for wheel speed signal recognition, and the recognized signal is input to the MCU 130.

[0049] The above solution can effectively identify the wheel speed signals of the standard protocol and the PWM protocol, but cannot process the signals of the AK protocol that carry more information.

[0050] In order to solve the above problems, the present application embodiment proposes a signal processing circuit, system and mobile carrier of a wheel speed sensor. Figures 2 to 7 Detailed description.

[0051] Before describing the embodiments of the present application in detail, three wheel speed sensor signals involved in the embodiments of the present application are briefly described first.

[0052] When the wheel speed sensor is working normally, there is a static current of 7mA. Under the standard protocol and PWM protocol, the current of the effective signal output by the wheel speed sensor is 14mA. Among them, the 14mA effective signal of the wheel speed sensor under the standard protocol includes wheel speed information, and the 14mA effective signal of the wheel speed sensor under the PWM protocol includes wheel speed and direction information. Under the AK protocol, the current of the effective signal output by the wheel speed sensor includes 14mA and 28mA, among which the 28mA effective signal includes wheel speed information, and the 14mA effective signal includes other information such as air gap and direction.

[0053] Figure 2 This is a schematic diagram of a signal filtering circuit in a signal processing circuit provided in an embodiment of the present application.

[0054] The signal processing circuit includes a signal filtering circuit 200 , and the signal filtering circuit 200 includes a first comparison element 210 , a second comparison element 220 and a first switch component 250 .

[0055] The first comparison element 210 is used to output a first signal greater than a first threshold value, and the second comparison element 220 is used to output a second signal greater than a second threshold value. The first signal and the second signal are both valid signals of the wheel speed sensor; when both the first signal and the second signal are output, the first switch component 250 is used to output the valid signals corresponding to the two current values ​​in the first signal and the second signal from the first output terminal and the second output terminal of the signal filtering circuit 200, respectively.

[0056] The first WSS signal input terminal is connected to the first input terminal of the first comparison element 210 , and the first WSS signal input terminal is connected to the second input terminal of the second comparison element 220 . The first input terminal and the second input terminal have the same direction.

[0057] For example, Figure 2 As shown, the first WSS signal input terminal is connected to the in-phase terminal 211 of the first comparison element 210, and the first WSS signal input terminal is connected to the in-phase terminal 221 of the second comparison element 220. At this time, the valid signals output by the first comparison element 210 and the second comparison element 220 are high level.

[0058] It should be understood that the first WSS signal input terminal maintains the same direction as the input terminals connected to the two comparison elements, and the embodiment of the present application does not limit the first WSS signal input terminal and the in-phase terminals of the two comparison elements (such as Figure 2 The “+” input terminal in the comparison element) or the inverting terminal of the two comparison elements (such as Figure 2 The “-” input terminal in the figure is connected, and this embodiment of the present application does not limit this.

[0059] Exemplarily, the first WSS signal input terminal is connected to the inverting terminal 212 of the first comparison element 210, and the first WSS signal input terminal is connected to the inverting terminal 222 of the second comparison element 220. At this time, the output signals of the first comparison element 210 and the second comparison element 220 are low level. It should be understood that this exemplary connection mode is not shown in the drawings.

[0060] The third input terminal of the first comparison element 210 is connected to the first reference voltage input terminal, and the fourth input terminal of the second comparison element 220 is connected to the second reference voltage input terminal, wherein the third input terminal and the fourth input terminal have the same direction, the first input terminal and the third input terminal have different directions, and the reference voltages of the first reference voltage input terminal and the second reference voltage input terminal are different.

[0061] For example, Figure 2 As shown, the inverting terminal 212 of the first comparison element 210 is connected to the first reference voltage input terminal, and the inverting terminal 222 of the second comparison element 220 is connected to the second reference voltage input terminal.

[0062] The output terminal 215 of the first comparison element 210 is connected to the first output terminal, and the output terminal of the second comparison element 220 is connected to the second output terminal.

[0063] The first switch component 250 is connected between the output terminal of the first comparison element 210 and the output terminal of the second comparison element 220 .

[0064] Exemplarily, the first threshold is 7 mA, and the second threshold is 14 mA. The first comparison element 210 is used to output a first signal greater than 7 mA, and the second comparison element is used to output a second signal greater than 14 mA.

[0065] It should be understood that the first comparison element 210 and the second comparison element 220 may be comparators, or other operational amplifier devices or other devices with a voltage comparison function, and the embodiment of the present application does not limit this.

[0066] When the WSS signal under the standard protocol or the PWM protocol is input into the first comparison element 210 and the second comparison element 220 through the first WSS signal input terminal, since the WSS signals under the standard protocol and the PWM protocol have two current levels of 7mA and 14mA, the first comparison element 210 can filter out the 14mA first signal with wheel speed information and output it from the first output terminal.

[0067] When the WSS signal under the AK protocol is input into the first comparison element 210 and the second comparison element 220 through the first WSS signal input terminal, since the WSS signal under the AK protocol has three current levels of 7mA, 14mA and 28mA, the first comparison element 210 can output first signals of 14mA and 28mA, and the second comparison element 220 can output a second signal of 28mA.

[0068] If both the first comparison element 210 and the second comparison element 220 have signal outputs, that is, both the first signal and the second signal are output, at this time, the first switch component 250 is turned on, so that the effective signal of the 14mA level and the effective signal of the 28mA level are output from the first output terminal and the second output terminal respectively.

[0069] For example, if the signal filtering circuit is Figure 2As shown, the WSS signal under the AK protocol is input from the in-phase end of the first comparison element 210 and the second comparison element 220, the valid signal output from the output end 215 of the first comparison element 210 is a high level, and the valid signal output from the output end 225 of the second comparison element 220 is a high level. At this time, the high level output by the output end 225 turns on the first switch 251 and changes the high level output by the first comparison element 210 to a low level. In this way, the first output end outputs a valid signal corresponding to the current level of 14mA, and the second output end outputs a valid signal corresponding to the current level of 28mA.

[0070] In the above technical solution, when both the output end 215 of the first comparison element 210 and the output end 225 of the second comparison element 220 have signal outputs, the first switch component 250 is turned on, so that the first output end and the second output end respectively output WSS signals corresponding to different current levels, thereby distinguishing between signals with wheel speed information and signals with other information under the AK protocol.

[0071] Optionally, the first switch component 250 includes a first switch 251 , a first end of the first switch 250 is connected to the first output end, and a third end of the first switch 250 is connected to the second output end.

[0072] It should be understood that the first switch 251 in the first switch component 250 may be a transistor, and the embodiment of the present application does not limit the type of the transistor.

[0073] A transistor refers to a single component based on semiconductor materials, including diodes (two terminals), triodes, field effect transistors, thyristors (the latter three are all three terminals) made of various semiconductor materials, among which field effect transistors are the most widely used.

[0074] The Metal Oxide Semiconductor Field Effect Transistor (MOSFET) is a field effect transistor that can be widely used in analog and digital circuits. According to the polarity of its "channel" (working carrier), MOSFET can be divided into two types: "N-type" and "P-type", namely N-type Metal Oxide Semiconductor (Negative-channel Metal Oxide Semiconductor, NMOS) and P-type Metal Oxide Semiconductor (Positive-channel Metal Oxide Semiconductor, PMOS).

[0075] When the transistor is implemented using MOSFET, the first and second ends of the transistor may refer to the drain (drain, referred to as D pole) and source (source, referred to as S pole) of the MOSFET respectively, and the third end of the transistor refers to the gate (gate, referred to as G pole) of the MOSFET.

[0076] For example, Figure 2 As shown, the effective signal output by the first comparison element 210 and the second comparison element 220 is a high level, the first switch 251 can be an NMOS, the first end of the NMOS is a D pole, the second end of the NMOS is an S pole, and the third end of the NMOS is a G pole. The D pole of the NMOS is connected to the first output terminal, the S pole of the NMOS is connected to the ground terminal, the G pole of the NMOS is connected to the second output terminal, and the first capacitor 252 and the first resistor 253 are connected in parallel between the G pole and the S pole of the NMOS. Among them, the diode in the NMOS can prevent electrostatic damage through the discharge path.

[0077] Exemplarily, if the valid signals output by the first comparison element 210 and the second comparison element 220 are at a low level, the first switch 251 may be a PMOS, the first end of the PMOS is a D pole, the second end of the PMOS is an S pole, and the third end of the PMOS is a G pole. The D pole of the PMOS is connected to the first output terminal, the S pole of the PMOS is connected to the power input terminal, the G pole of the PMOS is connected to the second output terminal, and the first capacitor 252 and the first resistor 253 are connected in parallel between the G pole and the S pole of the PMOS. It should be understood that this exemplary connection is not shown in the drawings.

[0078] When the transistor is implemented using a triode, the first end and the second end of the transistor may refer to the collector and the emitter of the triode respectively, and the third end refers to the base of the triode.

[0079] Exemplarily, if the valid signals output by the first comparison element 210 and the second comparison element 220 are at a high level, the first switch 251 may also be an NPN transistor, with the collector at the first terminal connected to the first output terminal, the base at the third terminal connected to the second output terminal, and the emitter at the second terminal connected to the ground terminal. It should be understood that this exemplary connection is not shown in the drawings.

[0080] Exemplarily, if the valid signals output by the first comparison element 210 and the second comparison element 220 are at a low level, the first switch 250 may also be a PNP-type transistor, with the emitter at the first terminal connected to the first output terminal, the base at the third terminal connected to the second output terminal, and the collector at the second terminal connected to the power input terminal. It should be understood that this exemplary connection is not shown in the drawings.

[0081] Optionally, the first switch component 250 further includes a first capacitor 252 and a first resistor 253 , and the first capacitor 252 and the first resistor 253 are connected in parallel between the third end and the second end of the first switch 251 .

[0082] The first capacitor 252 is used to adjust the driving speed of the first switch 251 , and the first resistor 253 is used to prevent the first switch 251 from switching on or off incorrectly and to accelerate the shutdown.

[0083] Optionally, the signal filtering circuit also includes a second resistor 230 and a third resistor 240, the second resistor 230 is connected between the output terminal 215 of the first comparison element 210 and the first end of the first switch 251; the third resistor 240 is connected between the output terminal 225 of the second comparison element 220 and the third end of the first switch 251.

[0084] The second resistor 230 is used to adjust the current waveform of the output signal of the first comparison element 210, thereby limiting the output current to prevent output short circuit failure, and the third resistor 240 is used to adjust the current waveform of the output signal of the second comparison element 220, thereby limiting the output current to prevent output short circuit failure.

[0085] Optionally, the signal filtering circuit also includes a first circuit 260, which is used to stabilize the power supply voltage. The first circuit 260 is connected between the power input terminal and the ground terminal, the power terminal 213 of the first comparison element 210 is connected to the power input terminal, and the power terminal 223 of the second comparison element 220 is connected to the power input terminal.

[0086] Exemplarily, the first circuit 260 includes a second capacitor 261 and a third capacitor 262 , and the second capacitor 261 and the third capacitor 262 are connected in parallel between the power input terminal and the ground terminal.

[0087] It should be understood that if the power supply terminal 213 of the first comparison element 210 and the power supply terminal 223 of the second comparison element 220 are connected to the same power supply input terminal, that is, the first comparison element 210 and the second comparison element 220 have the same power supply, then the power supply voltage can be stabilized by only one first circuit 260. If the power supply terminal 213 of the first comparison element 210 and the power supply terminal 223 of the second comparison element 220 are connected to different power supply input terminals, that is, the first comparison element 210 and the second comparison element 220 have independent power supplies, then each power supply input terminal is respectively connected to a voltage stabilizing circuit.

[0088] Figure 3 It is a schematic diagram of another signal filtering circuit in the signal processing circuit provided in an embodiment of the present application.

[0089] Optionally, the signal screening circuit 200 further includes a first voltage divider circuit 270, which is used to convert the reference voltage signal into a first reference voltage signal and a second reference voltage signal, and input them into the first reference voltage input terminal and the second reference voltage input terminal respectively.

[0090] For example, Figure 3 As shown, the signal screening circuit 200 also includes a first voltage dividing circuit 270, and there are two voltage dividing branches between the first voltage dividing circuit 270 and the ground terminal, namely a first voltage dividing branch 273 and a second voltage dividing branch 276. The first voltage dividing branch 273 is connected in series with a fourth resistor 271 and a fifth resistor 272, and the second voltage dividing branch 276 is connected in series with a sixth resistor 274 and a seventh resistor 275. The first reference voltage input terminal is connected between the fourth resistor 271 and the fifth resistor 272, and the second reference voltage input terminal is connected between the sixth resistor 274 and the seventh resistor 275.

[0091] In the technical solution of the present application, two reference voltage signals with different voltage values ​​can be output through a voltage divider circuit, which can reduce the number of reference voltage input terminals.

[0092] Figure 4 It is a schematic diagram of a fault detection circuit in a signal processing circuit provided in an embodiment of the present application.

[0093] The signal processing circuit includes a fault detection circuit 300 , and the fault detection circuit 300 includes a third comparison element 310 , a fourth comparison element 320 , a second switch component 330 and a third switch component 340 .

[0094] The third comparison element 310 is used to output a third signal that is less than a third threshold, and the fourth comparison element 320 is used to output a fourth signal that is greater than a fourth threshold.

[0095] It should be understood that the fault current range may be (fourth threshold, third threshold), and the fourth threshold and the third threshold are positive numbers.

[0096] When both the third signal and the fourth signal are output, the second switch component 330 and the third switch component 340 are used to control the fault signal to be output from the third output terminal, the fault current of the fault signal is greater than the fourth threshold, and the fault current of the fault signal is less than the third threshold.

[0097] The first WSS signal input terminal is connected to the fifth input terminal of the third comparison element 310 , the first WSS signal input terminal is connected to the sixth input terminal of the fourth comparison element 320 , and the fifth input terminal and the sixth input terminal have different directions.

[0098] For example, Figure 4As shown, the first WSS signal input terminal is connected to the inverting terminal 312 of the third comparison element 310, and the first WSS signal input terminal is connected to the non-inverting terminal 321 of the fourth comparison element 320. It should be understood that the first WSS signal input terminal is kept in a different direction from the input terminals connected to the two comparison elements, and the embodiment of the present application does not limit the first WSS signal input terminal to be connected to the non-inverting terminal of the third comparison element and the inverting terminal of the fourth comparison element; or the first WSS signal input terminal is connected to the inverting terminal of the third comparison element and the non-inverting terminal of the fourth comparison element (such as Figure 3 The present application embodiment does not limit this.

[0099] The seventh input terminal of the third comparison element 310 is connected to the third reference voltage input terminal, and the eighth input terminal of the fourth comparison element 320 is connected to the fourth reference voltage input terminal, wherein the seventh input terminal and the eighth input terminal have different directions, and the reference voltages of the third reference voltage input terminal and the fourth reference voltage input terminal are different.

[0100] For example, Figure 4 As shown, the input terminal of the third reference voltage is connected to the non-inverting terminal 311 of the third comparison element 310 , and the input terminal of the fourth reference voltage is connected to the inverting terminal 322 of the fourth comparison element 320 .

[0101] The second switch component 330 connects the output terminal 315 of the third comparison element 310 and the third output terminal, and the third switch component 340 connects the output terminal 325 of the fourth comparison element 320 and the second switch component 330 .

[0102] Specifically, the second switch component 330 includes a second switch 331 and an eighth resistor 332, and the third switch component 340 includes a third switch 341 and a ninth resistor 342. The first end of the second switch 331 is connected to the output end 315 of the third comparison element 310, the second end of the second switch 331 is connected to the third output end, the eighth resistor 332 is connected to the third end of the second switch 331 and the first end of the third switch 341; the second end of the third switch 341 is connected to the ground end, the ninth resistor 342 is connected between the third end of the third switch 341 and the second end of the third switch 341, and the third end of the third switch 341 is connected to the output end 325 of the fourth comparison element 320.

[0103] For example, Figure 4 As shown, the second switch 331 may be a PNP transistor, the first end of the second switch 331 is an emitter, the second end of the second switch 331 is a collector, and the third end of the second switch 331 is a base. The first end of the third switch 341 is a collector, the second end of the third switch 341 is an emitter, and the third end of the third switch 341 is a base.

[0104] Exemplarily, the second switch 331 may also be a PMOS, and the third switch 341 may also be an NMOS. The first end of the PMOS is a drain, the second end of the PMOS is a source, and the third end of the PMOS is a base. The first end of the NMOS is a drain, the second end of the NMOS is a source, and the third end of the NMOS is a base.

[0105] Optionally, the fault detection circuit 300 further includes a tenth resistor 380 , which is used to limit the current in the circuit to prevent damage to the third switch 341 .

[0106] One end of the tenth resistor 380 is connected to the power input end, and the other end of the tenth resistor 380 is connected to the first end of the third switch 341 and the eighth resistor 332 .

[0107] For example, if the fault detection circuit is Figure 4 As shown, the WSS signal is input from the inverting terminal of the third comparison element 310 and the non-inverting terminal of the fourth comparison element 320 .

[0108] For example, the fault range of the wheel speed sensor is (1, 3.8) mA, and the WSS signal is 3.5 mA. The third comparison element 310 is used to output a signal less than 3.8 mA, and the fourth comparison element 320 is used to output a signal greater than 1 mA. When the 3.5 mA WSS signal is input to the inverting end of the third comparison element 310 and the non-inverting end of the fourth comparison element 320, the valid signal output by the output end 315 of the third comparison element 310 is a high level signal, and the valid signal output by the output end 325 of the fourth comparison element 320 is a high level signal. At this time, the second switch 331 and the third switch 341 are turned on at the same time, and the fault signal is output from the third output end.

[0109] Optionally, the fault detection circuit 300 further includes a second circuit 350, which is used for filtering, stabilizing voltage and limiting output signal current, and is connected between the third output terminal and the ground terminal.

[0110] Exemplarily, the second circuit 350 includes a fourth capacitor 352 and an eleventh resistor 351. The fourth capacitor 352 and the eleventh resistor 351 are connected in parallel between the third output terminal and the ground terminal. The eleventh resistor 351 is a pull-down resistor, which is used to maintain a low level in the initial circuit and to limit the current of the output signal. The fourth capacitor is used for filtering and voltage stabilization.

[0111] Optionally, the fault detection circuit 300 further includes a third circuit 360, the third circuit 360 is used to stabilize the power supply voltage, and the third circuit 360 is connected between the power supply input terminal and the ground terminal. The power supply terminal 313 of the third comparison element 310 is connected to the power supply input terminal, and the power supply terminal 323 of the fourth comparison element 320 is connected to the power supply input terminal.

[0112] Specifically, the third circuit 360 includes a fifth capacitor 361 and a sixth capacitor 362 , and the fifth capacitor 361 and the sixth capacitor 362 are connected in parallel between the power input terminal and the ground terminal.

[0113] It should be understood that the third comparison element 310 and the fourth comparison element 320 are on the same chip and connected to the same power input terminal, so only one third circuit 360 is needed. If the third comparison element 310 and the fourth comparison element 320 have independent power supplies, then each power input terminal is connected to a voltage stabilizing circuit.

[0114] Optionally, the fault detection circuit 300 also includes a twelfth resistor 371 and a thirteenth resistor 372, the twelfth resistor 371 is connected between the output terminal 315 of the third comparison element 310 and the first end of the second switch 331, and the thirteenth resistor 372 is connected between the third end of the third switch 341 and the output terminal 325 of the fourth comparison element 320.

[0115] The twelfth resistor 371 is used to adjust the current waveform of the output signal of the third comparison element 310, thereby limiting the output current to prevent output short circuit failure. The thirteenth resistor 372 is used to adjust the current waveform of the output signal of the fourth comparison element 320, thereby limiting the output current to prevent output short circuit failure.

[0116] Figure 5 It is a schematic diagram of another fault detection circuit in the signal processing circuit provided in an embodiment of the present application.

[0117] Optionally, the fault detection circuit 300 further includes a second voltage divider circuit 390, which is used to convert the reference voltage signal into a third reference voltage signal and a fourth reference voltage signal, which are input into the third reference voltage input terminal and the fourth reference voltage input terminal respectively.

[0118] For example, Figure 5 As shown, the fault detection circuit 300 also includes a second voltage-dividing circuit 390, and there are two voltage-dividing branches between the second voltage-dividing circuit 390 and the ground terminal, namely a third voltage-dividing branch 393 and a fourth voltage-dividing branch 396. The third voltage-dividing branch 393 is connected in series with a fourteenth resistor 391 and a fifteenth resistor 392, and the fourth voltage-dividing branch 396 is connected in series with a sixteenth resistor 394 and a seventeenth resistor 395. The third reference voltage input terminal is connected between the fourteenth resistor 391 and the fifteenth resistor 392, and the fourth reference voltage input terminal is connected between the sixteenth resistor 394 and the seventeenth resistor 395.

[0119] In the technical solution of the present application, two reference voltage signals with different voltage values ​​can be output through a voltage divider circuit, which can reduce the number of reference voltage input terminals.

[0120] Figure 6 It is a schematic diagram of a sampling filter circuit of a signal processing circuit provided in an embodiment of the present application.

[0121] Optionally, the signal processing circuit further includes a sampling filter circuit 410, which is used to filter out high-frequency noise of the WSS signal. The second WSS signal input terminal of the sampling filter circuit 410 is connected to the wheel speed sensor, the first WSS signal output terminal of the sampling filter circuit 410 is connected to the first WSS signal input terminal of the signal screening circuit 200, and the first WSS signal output terminal of the sampling filter circuit 410 is connected to the first WSS signal input terminal of the fault detection circuit 300.

[0122] For example, Figure 6 As shown, the sampling filter circuit 410 includes an eighteenth resistor 411, a seventh capacitor 412 and an eighth capacitor 413. The eighteenth resistor 411 is connected between the second WSS signal input terminal and the first WSS signal output terminal, the seventh capacitor 412 is connected between one end of the eighteenth resistor 411 and the ground terminal, and the eighth capacitor 413 is connected between the other end of the eighteenth resistor 411 and the ground terminal.

[0123] Optionally, when the wheel speed sensor is a current type wheel speed sensor, the signal processing circuit also includes a current-voltage conversion element 430, which is used to convert the current signal of the WSS into a voltage signal of the WSS, and the current-voltage conversion element 430 is connected between the first WSS signal output terminal and the ground terminal.

[0124] For example, the wheel speed sensor may be a current type Hall wheel speed sensor.

[0125] Optionally, the signal processing circuit further includes a power supply circuit 420, and the power supply circuit 420 is used to supply power to the wheel speed sensor.

[0126] Exemplarily, the power supply circuit 420 provides a 12V voltage to the wheel speed sensor.

[0127] Figure 7 It is a system schematic diagram of a signal processing circuit provided in an embodiment of the present application.

[0128] The system includes a signal processing circuit 400 , a wheel speed sensor 710 and a processor 730 . The signal processing circuit 400 may include a sampling and filtering circuit 410 , a signal identification circuit 200 , a fault detection circuit 300 and a power supply circuit 420 .

[0129] Exemplarily, the power supply circuit 420 supplies power to the wheel speed sensor 710 .

[0130] Exemplarily, the WSS current signal output by the wheel speed sensor 710 is input into the sampling filter circuit 410 and the current-to-voltage conversion element 430 , and a WSS voltage signal after high-frequency noise is filtered out is output.

[0131] The WSS voltage signal is input to the signal identification circuit 200. The WSS voltage signal under the standard protocol or the PMW protocol is output from the first output terminal through the signal identification circuit 200, and the signal with the wheel speed information is input to the processor 730. The WSS voltage signal under the AK protocol is output from the second output terminal through the signal identification circuit 200, and the signal with the wheel speed information is input to the processor 730, and the signal with other information is output from the first output terminal and input to the processor 730.

[0132] The WSS voltage signal is input to the fault detection circuit 300. If the WSS voltage signal is within the fault current range, a fault signal is input to the processor 730 from the third output terminal.

[0133] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. 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.

[0134] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0135] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0136] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0137] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0138] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A signal processing circuit (400), characterized in that: include: A signal screening circuit (200), the signal screening circuit (200) comprising a first comparison element (210), a second comparison element (220) and a first switch component (250); The first comparison element (210) is used to output a first signal greater than a first threshold, and the second comparison element (220) is used to output a second signal greater than a second threshold, and the first signal and the second signal are both valid signals of the wheel speed sensor WSS; When both the first signal and the second signal are output, the first switch component (250) is used to output effective signals corresponding to two current values ​​in the first signal and the second signal from the first output terminal and the second output terminal of the signal screening circuit (200) respectively.

2. The signal processing circuit (400) according to claim 1, characterized in that: The first input end of the first comparison element (210) is connected to the first WSS signal input end, and the second input end of the second comparison element (220) is connected to the first WSS signal input end, wherein the first input end and the second input end have the same direction; The third input terminal of the first comparison element (210) is connected to the first reference voltage input terminal, and the fourth input terminal of the second comparison element (220) is connected to the second reference voltage input terminal, wherein the third input terminal and the fourth input terminal have the same direction, the third input terminal and the first input terminal have different directions, and the reference voltages of the first reference voltage input terminal and the second reference voltage input terminal are different; The output end (215) of the first comparison element (210) is connected to the first output end, and the output end (225) of the second comparison element (220) is connected to the second output end; The first switch component (250) is connected between an output terminal (215) of the first comparison element (210) and an output terminal (225) of the second comparison element (220).

3. The signal processing circuit (400) according to claim 2, characterized in that: The first switch component (250) comprises a first switch (251), a first end of the first switch (251) being connected to the first output end, and a third end of the first switch (251) being connected to the second output end.

4. The signal processing circuit (400) according to claim 3, characterized in that: The first switch component (250) further comprises a first capacitor (252) and a first resistor (253), and the first capacitor (252) and the first resistor (253) are connected in parallel between the third end of the first switch (251) and the second end of the first switch (251).

5. The signal processing circuit (400) according to any one of claims 1 to 4, characterized in that: The signal filtering circuit (200) further comprises a second resistor (230) and a third resistor (240), wherein the second resistor (230) is connected between the output end (215) of the first comparison element (210) and the first end of the first switch (251); and the third resistor (240) is connected between the output end (225) of the second comparison element (220) and the third end of the first switch (251).

6. The signal processing circuit (400) according to any one of claims 1 to 5, characterized in that: The signal filtering circuit (200) further comprises a first circuit (260), wherein the first circuit (260) is used to stabilize the power supply voltage, the first circuit (260) is connected between a power supply input terminal and a ground terminal, a power supply terminal (213) of the first comparison element (210) is connected to the power supply input terminal, and a power supply terminal (223) of the second comparison element (220) is connected to the power supply input terminal.

7. The signal processing circuit (400) according to any one of claims 2 to 6, characterized in that: The signal screening circuit (200) further comprises a first voltage divider circuit (270), wherein the first voltage divider circuit (270) is used to convert the reference voltage signal into the first reference voltage signal and the second reference voltage signal, which are input into the first reference voltage input terminal and the second reference voltage input terminal respectively.

8. The signal processing circuit (400) according to any one of claims 1 to 7, characterized in that: The signal processing circuit (400) further comprises a fault detection circuit (300), wherein the fault detection circuit (300) comprises a third comparison element (310), a fourth comparison element (320), a second switch component (330) and a third switch component (340); The third comparison element (310) is used to output a third signal that is less than a third threshold value; The fourth comparison element (320) is used to output a fourth signal greater than a fourth threshold; When both the third signal and the fourth signal are output, the second switch component (330) and the third switch component (340) are used to control a fault signal to be output from a third output terminal, a fault current of the fault signal being greater than the fourth threshold value, and the fault current being less than the third threshold value.

9. The signal processing circuit (400) according to claim 8, characterized in that: The fifth input terminal of the third comparison element (310) is connected to the first WSS signal input terminal, and the sixth input terminal of the fourth comparison element (320) is connected to the first WSS signal input terminal, wherein the fifth input terminal and the sixth input terminal have different directions; The seventh input terminal of the third comparison element (310) is connected to the third reference voltage input terminal, and the eighth input terminal of the fourth comparison element (320) is connected to the fourth reference voltage input terminal, wherein the seventh input terminal and the eighth input terminal have different directions, the fifth input terminal and the seventh input terminal have different directions, and the reference voltages of the third reference voltage input terminal and the fourth reference voltage input terminal are different; The second switch component (330) is connected to the output end (315) of the third comparison element (310) and the third output end, and the third switch component (340) is connected to the output end (325) of the fourth comparison element (320) and the second switch component (330).

10. The signal processing circuit (400) according to claim 9, characterized in that: The fault detection circuit (300) further comprises a second circuit (350), the second circuit (350) being used for filtering, stabilizing voltage and limiting output signal current, the second circuit (350) being connected between the third output terminal and the ground terminal.

11. The signal processing circuit (400) according to any one of claims 8 to 10, characterized in that: The fault detection circuit (300) further comprises a third circuit (360), the third circuit (360) being used for stabilizing the power supply voltage, the third circuit (360) being connected between a power supply input terminal and a ground terminal, the power supply terminal (313) of the third comparison element (310) being connected to the power supply input terminal, and the power supply terminal (323) of the fourth comparison element (320) being connected to the power supply input terminal.

12. The signal processing circuit (400) according to any one of claims 8 to 11, characterized in that: The fault detection circuit (300) further comprises a twelfth resistor (371) and a thirteenth resistor (372), wherein the twelfth resistor (371) is connected between the output end (315) of the third comparison element (310) and the first end of the second switch (331) of the second switch component (330), and the thirteenth resistor 372 is connected between the third end of the third switch (341) of the third switch component (340) and the output end (325) of the fourth comparison element (320).

13. The signal processing circuit (400) according to any one of claims 9 to 12, characterized in that: The fault detection circuit (300) further comprises a second voltage divider circuit (390), which is used to convert the reference voltage signal into the third reference voltage signal and the fourth reference voltage signal, and input them into the third reference voltage input terminal and the fourth reference voltage input terminal respectively.

14. The signal processing circuit (400) according to any one of claims 2 to 13, characterized in that: The signal processing circuit (400) further comprises a sampling filter circuit (410), and the sampling filter circuit (410) is used to filter out high-frequency noise of the WSS signal output by the wheel speed sensor.

15. The signal processing circuit (400) according to claim 14, characterized in that: The second WSS signal input end of the sampling and filtering circuit (410) is connected to the wheel speed sensor, and the first WSS signal output end of the sampling and filtering circuit (410) is connected to the first WSS signal input end.

16. The signal processing circuit (400) according to claim 15, characterized in that: The signal processing circuit (400) further comprises a current-voltage conversion element (430), wherein the current-voltage conversion element (430) is used to convert the current signal of the WSS after filtering out high-frequency noise into a voltage signal of the WSS, and the current-voltage conversion element (430) is connected between the first WSS signal output terminal and the ground terminal.

17. The signal processing circuit (400) according to any one of claims 1 to 16, characterized in that: The signal processing circuit (400) further comprises a power supply circuit (420), and the power supply circuit (420) is used to supply power to the wheel speed sensor.

18. A wheel speed sensor, characterized in that: The wheel speed sensor comprises the signal processing circuit (400) according to any one of claims 1 to 17.

19. A signal processing system, characterized in that: The signal processing system comprises a wheel speed sensor, a processor and a signal processing circuit (400) according to any one of claims 1 to 17, wherein the signal processing circuit (400) is connected between the wheel speed sensor and the processor.

20. A mobile carrier, characterized in that: The mobile carrier includes the signal processing circuit (400) according to any one of claims 1 to 17, or the mobile carrier includes the wheel speed sensor according to claim 18, or the mobile carrier includes the signal processing system according to claim 19.

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