A Hall sensor speed acquisition method and acquisition circuit with fault diagnosis

Abstract

The present invention provides a Hall sensor speed acquisition method and acquisition circuit with fault diagnosis, wherein a pull-up resistor is arranged inside the Hall sensor, a resistor is connected in series between the power supply end and the ground end of the Hall sensor, and a resistor is connected in parallel to the ground at the signal output end. In the Hall sensor speed acquisition method and acquisition circuit with fault diagnosis described in the present invention, a single-chip microcomputer detects whether there is a pulse signal at the signal acquisition end and a level signal of a fault feedback circuit, thereby identifying whether the speed test circuit is open, short-circuited, or the sensor itself is damaged, and effectively solves the problem that after the Hall sensor is installed and before the speed is acquired, there is no way to judge whether the sensor is good or bad, which brings inconvenience to the use.

Description

Technical Field

[0001] The invention belongs to the technical field of sensors and signal acquisition, and in particular relates to a rotation speed acquisition method and an acquisition circuit of a Hall sensor with fault diagnosis. Background Art

[0002] In engine control, the speed sensor is a necessary component. The most commonly used sensors are magnetoelectric and Hall type. Among them, the Hall sensor is the most widely used due to its superior ability to test low speeds and strong anti-interference ability. Hall sensors are generally composed of integrated Hall elements and magnetic steel. The output signal is a rectangular wave pulse signal. Signal conversion circuit is no longer required, and speed acquisition can be performed directly. When there is no speed signal, the sensor will output a high level or low level signal due to the different positions of the test probe at the top of the tooth or the secondary slot of the measuring gear. In this way, before the speed acquisition, there is no basis for self-diagnosis of whether the sensor has a fault; and the Hall sensor is an integrated chip. Unlike magnetoelectric sensors, it can test the coil resistance online to see if it is within a reasonable range for fault judgment. After the Hall sensor is installed, there is no way to judge the quality of the sensor before the speed acquisition, which brings inconvenience to use. Summary of the invention

[0003] In view of this, the present invention aims to propose a Hall sensor speed acquisition method with fault diagnosis to solve the problem that after the Hall sensor is installed and before the speed is acquired, there is no way to judge the quality of the sensor, which brings inconvenience to the use.

[0004] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0005] A Hall sensor speed acquisition method with fault diagnosis includes arranging a pull-up resistor inside the Hall sensor, connecting a resistor in series between a power supply terminal and a ground terminal of the Hall sensor, and connecting a resistor in parallel to the ground at a signal output terminal.

[0006] Compared with the prior art, the Hall sensor speed acquisition method with fault diagnosis described in the present invention has the following advantages:

[0007] (1) In the Hall sensor speed acquisition method with fault diagnosis described in the present invention, the single chip microcomputer detects whether there is a pulse signal at the signal acquisition end and the level signal of the fault feedback circuit, and thereby identifies whether the speed test circuit is open circuit, short circuit, or the sensor itself is damaged. This effectively solves the problem that after the Hall sensor is installed, there is no way to judge the quality of the sensor before the speed is acquired, which brings inconvenience to the use.

[0008] Another object of the present invention is to provide a Hall sensor speed acquisition circuit with fault diagnosis to solve the problem that after the Hall sensor is installed and before the speed is acquired, there is no way to judge the quality of the sensor, which brings inconvenience to the use.

[0009] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0010] A Hall sensor speed acquisition circuit with fault diagnosis includes a Hall sensor, and is characterized in that: the output end of the Hall sensor is respectively connected to a speed acquisition circuit and a level fault discrimination circuit through a signal filtering circuit, the lower boundary discrimination of the current fault discrimination circuit and the level discrimination circuit share a comparator U1B, the upper boundary of the current fault discrimination circuit is connected to the ground wire of the Hall sensor, the level fault discrimination circuit and the current fault discrimination circuit together form a fault feedback signal that enters a single-chip microcomputer, and the speed acquisition circuit outputs a rectangular wave signal connected to the single-chip microcomputer.

[0011] Furthermore, the Hall sensor has a built-in pull-up resistor Rx, a level matching resistor R1 is connected in series between the power supply end of the Hall sensor and the system power supply +5V, a level matching resistor R2 is connected in series between the ground line of the Hall sensor and the system ground GND, and a level matching resistor R3 is connected in series between the output end of the Hall sensor and the system ground GND.

[0012] Furthermore, the signal filtering circuit includes a filtering resistor R4 and a filtering capacitor C1, the output signal of the Hall sensor is connected to the first end of the filtering resistor R4, and the second end of the filtering resistor R4 is connected to the system ground GND after passing through the filtering capacitor C1.

[0013] Furthermore, the speed acquisition circuit includes a comparator U2A and an inverter U3A, the negative input terminal 2 of the comparator U2A is connected to the second end of the filter resistor R4, the positive input terminal 3 of the comparator U2A is connected to the system ground GND through the voltage divider resistor R11 and to the system power supply +5V through the voltage divider resistor R10, the output terminal 1 of the comparator U2A is connected to the input terminal 2 of the Schmitt trigger U3A, and the output terminal 3 of U3A outputs a rectangular wave signal connected to the single-chip microcomputer; the 8th and 4th pins of the comparator U2A are respectively connected to the system power supply +5V and the system ground GND.

[0014] Furthermore, the level fault judgment circuit includes a comparator U1A and a comparator U1B, the positive input terminal pin 3 of the comparator U1A is connected to one end of the voltage divider resistor R5 and the voltage divider resistor R6, and the other end of the voltage divider resistor R5 and the voltage divider resistor R6 is respectively connected to the system power supply +5V and the system ground GND; the negative input terminal pin 6 of the comparator U1B is connected to one end of the voltage divider resistor R7 and the voltage divider resistor R8, and the other end of the voltage divider resistor R7 and the voltage divider resistor R8 is respectively connected to the system power supply +5V and the system ground GND; the negative input terminal pin 2 of the comparator U1A and the positive input terminal pin 6 of the comparator U1B are both connected to the second end of the filter resistor R4.

[0015] Furthermore, the level fault determination circuit and the current fault determination circuit share the comparator U1B and the voltage-dividing resistors R7 and R8 at the lower boundary.

[0016] Furthermore, the upper boundary of the current fault judgment circuit includes a judgment comparator U4A, the negative input terminal 2 pin of the comparator U4A is connected to the ground line of the Hall sensor, the positive input terminal 3 pin of the comparator U4A is connected to one end of the voltage divider resistor R12 and the voltage divider resistor R13, and the other ends of the voltage divider resistor R12 and the voltage divider resistor R13 are respectively connected to the system power supply +5V and the system ground GND; the output terminal 1 pin of the comparator U1A, the output terminal 7 pin of the comparator U1B, and the output terminal 1 pin of the comparator U4A are connected together to form a fault feedback signal entering the single-chip microcomputer, and at the same time connected to the system power supply +5V through the pull-up resistor R9.

[0017] The Hall sensor speed acquisition circuit with fault diagnosis has the same advantages as the Hall sensor speed acquisition method with fault diagnosis over the prior art, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0019] Figure 1 It is a collection principle diagram of the Hall sensor speed collection circuit with fault diagnosis according to an embodiment of the present invention;

[0020] Figure 2 A schematic diagram of a conventional speed output signal according to an embodiment of the present invention;

[0021] Figure 3 A schematic diagram of a speed output signal of a Hall sensor speed acquisition circuit with fault diagnosis according to an embodiment of the present invention;

[0022] Figure 4A schematic diagram of a power supply circuit fault of a Hall sensor speed acquisition circuit with fault diagnosis according to an embodiment of the present invention;

[0023] Figure 5 A schematic diagram of a sensor chip failure of a Hall sensor speed acquisition circuit with fault diagnosis according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0025] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0026] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0027] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0028] A method for collecting the rotational speed of a Hall sensor with fault diagnosis. A pull-up resistor is set inside the Hall sensor, a resistor is connected in series between the power supply terminal and the ground terminal of the Hall sensor, and a resistor is connected in parallel between the signal output terminal and the ground. When there is no rotational speed in the static state, the signal output by the sensor is no longer a featureless signal with a low level of 0V and a high level of 5V like a conventional sensor; the signal received by the acquisition circuit is higher than the system ground wire 0V by a voltage difference and lower than the power supply 5V by a voltage difference, and fault feedback is given through the set upper and lower boundary operating currents of the sensor. The single-chip microcomputer identifies faults such as open circuit, short circuit, and damage to the sensor itself in the rotational speed test loop based on whether there is a pulse signal at the signal acquisition terminal of the acquired signal and the level signal of the fault feedback circuit.

[0029] As Figures 1 to 5 shown, a rotational speed acquisition circuit of a Hall sensor with fault diagnosis includes a Hall sensor, a signal filtering circuit, a rotational speed acquisition circuit, a level fault discrimination circuit, a current fault discrimination circuit, and a single-chip microcomputer. The output terminal of the Hall sensor is respectively connected to the rotational speed acquisition circuit and the level fault discrimination circuit through the signal filtering circuit. The lower boundary discrimination of the current fault discrimination circuit and the level discrimination circuit share the comparator U1B. The upper boundary of the current fault discrimination circuit is connected to the ground wire of the Hall sensor. The level fault discrimination circuit and the current fault discrimination circuit together form a fault feedback signal and enter the single-chip microcomputer. The rotational speed acquisition circuit outputs a rectangular wave signal and connects it to the single-chip microcomputer.

[0030] The Hall sensor has an internal pull-up resistor Rx. A level matching resistor R1 is connected in series between the power supply terminal of the Hall sensor and the system power supply +5V. A level matching resistor R2 is connected in series between the ground wire of the Hall sensor and the system ground GND. A level matching resistor R3 is connected in series between the output terminal of the Hall sensor and the system ground GND.

[0031] The signal filtering circuit includes a filtering resistor R4 and a filtering capacitor C1. The signal at the output terminal of the Hall sensor is connected to the first end of the filtering resistor R4, and the second end of the filtering resistor R4 is connected to the system ground GND after passing through the filtering capacitor C1.

[0032] The rotational speed acquisition circuit includes a comparator U2A and an inverter U3A. The negative input terminal 2 of the comparator U2A is connected to the second end of the filtering resistor R4. The positive input terminal 3 of the comparator U2A is respectively connected to the system ground GND through a voltage dividing resistor R11 and to the system power supply +5V through a voltage dividing resistor R10. The output terminal 1 of the comparator U2A is connected to the input terminal 2 of the Schmitt trigger U3A. The output terminal 3 of U3A outputs a rectangular wave signal and connects it to the single-chip microcomputer; the 8th and 4th pins of the comparator U2A are respectively connected to the system power supply +5V and the system ground GND.

[0033] The level fault judgment circuit includes a comparator U1A and a comparator U1B. The positive input terminal 3 pin of the comparator U1A is connected to one end of the voltage-dividing resistor R5 and the voltage-dividing resistor R6, and the other ends of the voltage-dividing resistor R5 and the voltage-dividing resistor R6 are respectively connected to the system power supply +5V and the system ground GND; the negative input terminal 6 pin of the comparator U1B is connected to one end of the voltage-dividing resistor R7 and the voltage-dividing resistor R8, and the other ends of the voltage-dividing resistor R7 and the voltage-dividing resistor R8 are respectively connected to the system power supply +5V and the system ground GND; the negative input terminal 2 pin of the comparator U1A and the positive input terminal 6 pin of the comparator U1B are both connected to the second end of the filter resistor R4.

[0034] The level fault determination circuit and the current fault determination circuit share the comparator U1B and the voltage dividing resistors R7 and R8 at the lower boundary.

[0035] The upper boundary of the current fault judgment circuit includes the judgment comparator U4A, the negative input terminal 2 pin of the comparator U4A is connected to the ground wire of the Hall sensor, the positive input terminal 3 pin of the comparator U4A is connected to one end of the voltage divider resistor R12 and the voltage divider resistor R13, and the other ends of the voltage divider resistor R12 and the voltage divider resistor R13 are respectively connected to the system power supply +5V and the system ground GND; the output terminal 1 pin of the comparator U1A, the output terminal 7 pin of the comparator U1B, and the output terminal 1 pin of the comparator U4A are connected together to form a fault feedback signal entering the microcontroller, and at the same time connected to the system power supply +5V through the pull-up resistor R9.

[0036] The English abbreviation of single chip microcomputer is MCU.

[0037] like Figure 2 As shown, based on the 5V power supply of the Hall sensor, the normal speed outputs a rectangular wave signal n, the low level is 0V, and the high level is 5V.

[0038] like Figure 3 As shown, the present invention is based on the 5V power supply and matching resistor of the Hall sensor, and the speed outputs a rectangular wave signal n, the low level is 0.5V, and the high level is 4.5V.

[0039] The analysis is as follows:

[0040] This speed acquisition method uses the wide power supply range of the Hall sensor to set a 1K pull-up resistor inside the Hall sensor, connect a 10-ohm resistor in series from the sensor power supply end to the system power supply 5V, connect a 50-ohm resistor in series from the ground end to the system ground GND, and pull down a 9K matching resistor from the signal output end to the system ground GND. Based on the simplified model working principle of the inductive core inside the Hall sensor and the equivalent output mode of the transistor T1, if the sensor has no fault, and there is no short circuit or open circuit fault in the power supply, output, and ground test circuits, when the sensor test probe is at the top of the tooth of the measuring toothed disc, the transistor is turned on and outputs a low level. Based on the design parameters of the Hall sensor working current of 10mA, the voltage on the level matching resistor is 0.5V, the voltage drop on the transistor T is 0.02V, and the voltage of the output signal is about 0.5V; when the sensor test probe is in the tooth groove of the measuring toothed disc, the transistor is cut off and outputs a high level. Based on the matching resistor R1, the internal pull-up resistor Rx of the sensor and the resistor R3 connected to the GND at the output end, the voltage of the output signal after voltage division is about 4.5V.

[0041] like Figure 4 As shown, there is no speed signal between t0 and t1, the sensor and the test loop cable are fault-free, the collected level voltage is between 0.45V and 4.55V, and the fault feedback terminal output is high level; fault type 1 occurs between t1 and t2, including: sensor power supply short circuit problem, sensor output short circuit problem, sensor output to power supply ground short circuit problem, the collected level voltage is lower than 0.45V, and the fault feedback terminal output is low level; fault type 2 occurs between t2 and t3, including: sensor power supply ground short circuit problem, sensor output to power supply short circuit problem, the collected level voltage is greater than 4.55V, and the fault feedback terminal output is low level; there is no speed signal between t3 and t4, and the sensor is normal and fault-free; the collected speed signal is normal between t4 and t5. In this state, there is no need to worry about the fault feedback state, the sensor is normal, and the test loop is normal.

[0042] like Figure 5 As shown, between t0 and t1, an internal short circuit problem occurs in the sensor chip, the sensor power supply is basically 0mA, there is no voltage drop on the level matching resistor R1, the collected level voltage is greater than 4.55V, and the fault feedback terminal output is a low level; between t1 and t2, an internal short circuit problem occurs in the sensor chip, the sensor power supply current increases, and when the voltage drop on the level matching resistor R2 is greater than the designed upper limit of the normal working current of 15mA, the fault feedback terminal output is a low level.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A Hall sensor speed acquisition method with fault diagnosis, Features: A pull-up resistor is arranged inside the Hall sensor, a resistor is connected in series between the power supply terminal and the ground terminal of the Hall sensor, and a resistor is connected in parallel to the ground at the signal output terminal.

2. A collection circuit for a Hall sensor speed collection method with fault diagnosis as claimed in claim 1, comprising a Hall sensor, Features: The output end of the Hall sensor is connected to the speed acquisition circuit and the level fault judgment circuit respectively through the signal filtering circuit. The lower boundary judgment of the current fault judgment circuit and the level judgment circuit share the comparator U1B. The upper boundary of the current fault judgment circuit is connected to the ground wire of the Hall sensor. The level fault judgment circuit and the current fault judgment circuit together form a fault feedback signal that enters the single-chip microcomputer. The speed acquisition circuit outputs a rectangular wave signal connected to the single-chip microcomputer.

3. A Hall sensor speed acquisition circuit with fault diagnosis according to claim 2, Features: The Hall sensor has a built-in pull-up resistor Rx, a level matching resistor R1 is connected in series between the power supply end of the Hall sensor and the system power supply +5V, a level matching resistor R2 is connected in series between the ground line of the Hall sensor and the system ground GND, and a level matching resistor R3 is connected in series between the output end of the Hall sensor and the system ground GND.

4. A Hall sensor speed acquisition circuit with fault diagnosis according to claim 3, Features: The signal filtering circuit includes a filtering resistor R4 and a filtering capacitor C1. The output signal of the Hall sensor is connected to the first end of the filtering resistor R4. The second end of the filtering resistor R4 is connected to the system ground GND after passing through the filtering capacitor C1.

5. A Hall sensor speed acquisition circuit with fault diagnosis according to claim 2, Features: The speed acquisition circuit includes a comparator U2A and an inverter U3A. The negative input terminal 2 of the comparator U2A is connected to the second end of the filter resistor R4. The positive input terminal 3 of the comparator U2A is connected to the system ground GND through a voltage divider resistor R11 and to the system power supply +5V through a voltage divider resistor R10. The output terminal 1 of the comparator U2A is connected to the input terminal 2 of the Schmitt trigger U3A. The output terminal 3 of U3A outputs a rectangular wave signal connected to the single-chip microcomputer. Pin 8 and pin 4 of comparator U2A are connected to system power supply +5V and system ground GND respectively.

6. A Hall sensor speed acquisition circuit with fault diagnosis according to claim 2, Features: The level fault judgment circuit includes a comparator U1A and a comparator U1B. The positive input terminal 3 pin of the comparator U1A is connected to one end of the voltage-dividing resistor R5 and the voltage-dividing resistor R6, and the other ends of the voltage-dividing resistor R5 and the voltage-dividing resistor R6 are respectively connected to the system power supply +5V and the system ground GND; the negative input terminal 6 pin of the comparator U1B is connected to one end of the voltage-dividing resistor R7 and the voltage-dividing resistor R8, and the other ends of the voltage-dividing resistor R7 and the voltage-dividing resistor R8 are respectively connected to the system power supply +5V and the system ground GND; the negative input terminal 2 pin of the comparator U1A and the positive input terminal 6 pin of the comparator U1B are both connected to the second end of the filter resistor R4.

7. A Hall sensor speed acquisition circuit with fault diagnosis according to claim 2 or 6, Features: The level fault determination circuit and the current fault determination circuit share the comparator U1B and the voltage dividing resistors R7 and R8 at the lower boundary.

8. A Hall sensor speed acquisition circuit with fault diagnosis according to claim 7, Features: The upper boundary of the current fault judgment circuit includes the judgment comparator U4A, the negative input terminal 2 pin of the comparator U4A is connected to the ground wire of the Hall sensor, the positive input terminal 3 pin of the comparator U4A is connected to one end of the voltage divider resistor R12 and the voltage divider resistor R13, and the other ends of the voltage divider resistor R12 and the voltage divider resistor R13 are respectively connected to the system power supply +5V and the system ground GND; the output terminal 1 pin of the comparator U1A, the output terminal 7 pin of the comparator U1B, and the output terminal 1 pin of the comparator U4A are connected together to form a fault feedback signal entering the microcontroller, and at the same time connected to the system power supply +5V through the pull-up resistor R9.

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