Gear orthogonal output speed measuring device based on Hall element

Abstract

The invention discloses a gear orthogonal output speed measuring device based on a Hall element, and belongs to the technical field of integrated circuits, the gear orthogonal output speed measuring device comprises a shell, a support, a permanent magnet and an IC, the permanent magnet and the IC are both installed on the support, the permanent magnet is used for generating a stable magnetic field, and the support is sleeved with the shell; according to the invention, the motion position and speed of the detected magnetic target are detected at different points by using the plurality of Hall units arranged in an array manner and by using the magnetic field intensity, and the magnetic flux formed by the detected magnetic target with the motion and position change is measured through an independent measurement channel formed by different Hall units, so that the anti-interference performance on radial vibration is realized; the problems that the speed measurement of the current vehicle transmission wheel assembly is easily interfered, and the phase angle deviation under the fixed duty ratio in the full speed section is too large are solved.

Description

Technical Field

[0001] The invention relates to a gear orthogonal output speed measuring device based on a Hall element, belonging to the technical field of integrated circuits. Background Art

[0002] At present, the speed measurement of vehicle transmission wheel assemblies is mainly focused on gears, and the measurement of gears is mainly carried out through Hall devices. Each Hall unit in the Hall device includes active offset compensation, and the amplifier pre-processes the voltage signal of the Hall unit. Since the gears are always rotating, if the difference in the response speed of each unit has a large apparent delay, then the sinusoidal signal measured by the Hall unit will also have an equal fixed time difference. In this case, the theoretical phase angle deviation at different speeds (equivalent to frequency) will not be a constant value. The phase angle at a fixed duty cycle in the full speed range will produce a very large deviation. Once the phase angle deviation reaches 180° in the high frequency band, the output signal will be unfavorable for determining the direction of rotation, which will have serious consequences for subsequent instruments and control systems. Summary of the Invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a transmission wheel assembly speed measuring device that can independently measure the magnetic flux formed by the moving and position-changing magnetic target being measured, has anti-interference properties against radial vibration, and solves the current problems of vehicle transmission wheel assembly speed measurement being susceptible to interference and excessive phase angle deviation under a fixed duty cycle in the full speed range.

[0004] In order to solve the above technical problems, the present invention is implemented by adopting the following technical solutions: A gear quadrature output speed measuring device based on a Hall element, comprising: shell; a bracket, disposed in the housing; A permanent magnet is provided on the bracket; The IC is mounted on a bracket and includes a plurality of Hall elements arranged in an array for responding at different points to the changing differential magnetic field generated by a rotating ring magnet and an iron target coupled to the magnet during rotation, an operational amplifier connected to the Hall element, a filter connected to the operational amplifier, a Schmitt trigger connected to the filter, and a drive gate circuit connected to the Schmitt trigger.

[0005] Optionally, the Hall unit includes a first unit, a second unit, a third unit and a fourth unit; The first unit and the third unit have orthogonal outputs and form an A-phase measurement channel corresponding to the second unit; The second unit and the fourth unit have orthogonal outputs and form a B-phase measurement channel corresponding to the third unit.

[0006] Optionally, the support material includes modified plastic of glass fiber and black masterbatch.

[0007] Optionally, a potting structure is further provided between the housing and the bracket, and the potting structure includes epoxy potting glue 9002.

[0008] Optionally, the first unit, the second unit, the third unit and the fourth unit are arranged at equal distances.

[0009] Optionally, the distance between the geometric center of the A-phase measurement channel and the geometric center of the B-phase measurement channel is .

[0010] Optionally, the signal polarity of the A-phase measurement channel is opposite to the signal polarity of the B-phase measurement channel.

[0011] Optionally, when the measured transmission wheel passes through the first unit, the square wave of the phase A measurement channel is pulled low; when passing through the second unit, the square wave of the phase B measurement channel is pulled high; when passing through the third unit, the square wave of the phase A measurement channel is pulled low; when passing through the fourth unit, the square wave of the phase B measurement channel is pulled low.

[0012] Optionally, the output end of the first unit is connected to an operational amplifier A1, the output end of the third unit is connected to an operational amplifier A2, the output ends of the operational amplifier A1 and the operational amplifier A2 are connected to a first operational amplifier, the output end of the first operational amplifier is connected to a first filter, the output end of the first filter is connected to a first Schmitt trigger, and the first Schmitt trigger is connected to a driving gate circuit.

[0013] Optionally, the output end of the second unit is connected to an operational amplifier B1, the output end of the fourth unit is connected to an operational amplifier B2, the output ends of the operational amplifier B1 and the operational amplifier B2 are connected to a second operational amplifier, the output end of the second operational amplifier is connected to a second filter, the output end of the second filter is connected to a second Schmitt trigger, and the second Schmitt trigger is connected to the driving gate circuit.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention utilizes multiple arrayed Hall elements to detect the moving position and speed of a magnetic target using magnetic field strength at different points. The magnetic flux generated by the moving and position-changing magnetic target is measured through independent measurement channels formed by different Hall elements. This method is resistant to radial vibration and solves the current problems of vehicle transmission wheel assembly speed measurement being susceptible to interference and excessive phase angle deviation at a fixed duty cycle within the full speed range.

[0015] 2. The present invention forms an A-phase measurement channel corresponding to the second unit through the orthogonal output of the first unit and the third unit, and forms a B-phase measurement channel corresponding to the third unit through the orthogonal output of the second unit and the fourth unit. When the measured transmission wheel passes through the first unit, the square wave of the A-phase measurement channel is pulled low, and when passing through the second unit, the square wave of the B-phase measurement channel is pulled high. When passing through the third unit, the square wave of the A-phase measurement channel is pulled low, and when passing through the fourth unit, the square wave of the B-phase measurement channel is pulled low. In the measurement cycle of the measured transmission wheel, the phase difference is equivalent to 90°. The A and B-phase square waves are synchronized with the gears, and the rotation direction can be read through the square wave sequence. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 1 is a schematic diagram of the overall structure of a gear orthogonal output speed measuring device based on a Hall element provided in an embodiment of the present invention; Figure 2 1 is a schematic diagram of the IC structure of a gear quadrature output speed measuring device based on a Hall element provided by an embodiment of the present invention; Figure 3 This is a schematic diagram of the change direction of the square wave of the Hall element of a gear orthogonal output speed measurement device based on a Hall element provided by an embodiment of the present invention; Figure 4 The present invention is a schematic diagram of a self-calibration of the offset voltage of the first unit and the third unit of a gear quadrature output speed measuring device based on a Hall element provided by an embodiment of the present invention.

[0017] In the figure: 1. Housing; 2. Bracket; 3. Permanent magnet; 4. IC; 401. First unit; 402. Second unit; 403. Third unit; 404. Fourth unit; 5. A-phase measurement channel; 601. Operational amplifier A1; 602. Operational amplifier A2; 603. First operational amplifier; 604. First filter; 605. First Schmitt trigger; 7. B-phase measurement channel; 801. Operational amplifier B1; 802. Operational amplifier B2; 803. Second operational amplifier; 804. Second filter; 805. Second Schmitt trigger; 9. Drive gate circuit. DETAILED DESCRIPTION

[0018] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0019] 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 orientations or positional relationships based on the orientations 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", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. 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.

[0020] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0021] Example 1 like Figure 1 As shown, a gear orthogonal output speed measuring device based on a Hall element includes a housing 1, a bracket 2, a permanent magnet 3 and an IC, wherein the permanent magnet 3 and the IC4 are both mounted on the bracket 2, the permanent magnet 3 is used to generate a stable magnetic field, and the housing 1 is sleeved on the outside of the bracket 2; IC4 includes a plurality of Hall elements arranged in an array for responding at different points to the changing differential magnetic field generated by the rotating ring magnet and the iron target coupled to the magnet during rotation, an operational amplifier connected to the Hall element, a filter connected to the operational amplifier, a Schmitt trigger connected to the filter, and a drive gate circuit 9 connected to the Schmitt trigger. Specifically: like Figure 2 As shown, the Hall unit includes a first unit 401, a second unit 402, a third unit 403 and a fourth unit 404. In this embodiment, the first unit 401, the second unit 402, the third unit 403 and the fourth unit 404 are arranged equidistantly. The first unit 401 and the third unit 403 have quadrature outputs and form an A-phase measurement channel 5 corresponding to the second unit 402. The output of the first unit 401 is connected to an operational amplifier A1601, and the output of the third unit 403 is connected to an operational amplifier A2602. The outputs of the operational amplifiers A1601 and A2602 are connected to a first operational amplifier 603. The output of the first operational amplifier 603 is connected to a first filter 604. The output of the first filter 604 is connected to a first Schmitt trigger 605. The first Schmitt trigger 605 is connected to the drive gate circuit 9. The second unit 402 and the fourth unit 404 have quadrature outputs and form a B-phase measurement channel 7 corresponding to the third unit 403. The output of the second unit 402 is connected to an operational amplifier B1801, and the output of the fourth unit 404 is connected to an operational amplifier B2802. The outputs of the operational amplifiers B1801 and B2802 are connected to a second operational amplifier 803. The output of the second operational amplifier 803 is connected to a second filter 804. The output of the second filter 804 is connected to a second Schmitt trigger 805. The second Schmitt trigger 805 is connected to the drive gate circuit 9. The signal polarity of the A-phase measurement channel 5 is opposite to that of the B-phase measurement channel 7, and the distance between the geometric center of the A-phase measurement channel 5 and the geometric center of the B-phase measurement channel 7 is ; In this embodiment, the distance between the geometric center of the A-phase measurement channel 5 and the geometric center of the B-phase measurement channel 7 is 1 mm. It should be noted that the width of each tooth of the gear in the existing vehicle transmission wheel assembly is not less than 2 mm. Therefore, the distance between the A-phase measurement channel 5 and the B-phase measurement channel 7 can meet the measurement of the full-speed running gear.

[0022] Example 2

[0023] like Figure 1 As shown, a gear orthogonal output speed measuring device based on a Hall element includes a housing 1, a bracket 2, a permanent magnet 3 and an IC, wherein the permanent magnet 3 and the IC are both mounted on the bracket 2, the permanent magnet 3 is used to generate a stable magnetic field, and the housing 1 is sleeved on the outside of the bracket 2; In this embodiment, the material of the bracket 2 is modified plastic of glass fiber and black masterbatch, whose physical properties can withstand high temperatures of 225°C. At the same time, its expansion coefficient is 0.00003 cm / cm / °C, which is a raw material with a low expansion coefficient; A potting structure is also provided between the housing 1 and the bracket 2. The potting structure includes epoxy potting glue 9002, which has a heat resistance of -60 to 260°C.

[0024] The IC includes a plurality of Hall elements arranged in an array for responding at different points to the changing differential magnetic field generated by a rotating ring magnet and an iron target coupled to the magnet during rotation, an operational amplifier connected to the Hall element, a filter connected to the operational amplifier, a Schmitt trigger connected to the filter, and a drive gate circuit 9 connected to the Schmitt trigger. Specifically: like Figure 2 As shown, the Hall unit includes a first unit 401, a second unit 402, a third unit 403 and a fourth unit 404. In this embodiment, the first unit 401, the second unit 402, the third unit 403 and the fourth unit 404 are arranged equidistantly. The first unit 401 and the third unit 403 have quadrature outputs and form an A-phase measurement channel 5 corresponding to the second unit 402. The output of the first unit 401 is connected to an operational amplifier A1601, and the output of the third unit 403 is connected to an operational amplifier A2602. The outputs of the operational amplifiers A1601 and A2602 are connected to a first operational amplifier 603. The output of the first operational amplifier 603 is connected to a first filter 604. The output of the first filter 604 is connected to a first Schmitt trigger 605. The first Schmitt trigger 605 is connected to the drive gate circuit 9. The second unit 402 and the fourth unit 404 have quadrature outputs and form a B-phase measurement channel 7 corresponding to the third unit 403. The output of the second unit 402 is connected to an operational amplifier B1801, and the output of the fourth unit 404 is connected to an operational amplifier B2802. The outputs of the operational amplifiers B1801 and B2802 are connected to a second operational amplifier 803. The output of the second operational amplifier 803 is connected to a second filter 804. The output of the second filter 804 is connected to a second Schmitt trigger 805. The second Schmitt trigger 805 is connected to the drive gate circuit 9. The signal polarity of the A-phase measurement channel 5 is opposite to that of the B-phase measurement channel 7, and the distance between the geometric center of the A-phase measurement channel 5 and the geometric center of the B-phase measurement channel 7 is In this embodiment, the distance between the geometric center of the A-phase measurement channel 5 and the geometric center of the B-phase measurement channel 7 is 1 mm. It should be noted that the width of each gear tooth in the existing vehicle transmission wheel assembly is not less than 2 mm. Therefore, the distance between the A-phase measurement channel 5 and the B-phase measurement channel 7 can meet the measurement requirements for gears running at full speed. When the measured transmission wheel passes through the first unit 401, the square wave of the A-phase measurement channel 5 is pulled low. When passing through the second unit 402, the square wave of the B-phase measurement channel 7 is pulled high. When passing through the third unit 403, the square wave of the A-phase measurement channel 5 is pulled low. When passing through the fourth unit 404, the square wave of the B-phase measurement channel 7 is pulled low. In the measurement cycle of the measured transmission wheel, the phase difference is equivalent to 90°. Both the A-phase and B-phase square waves are synchronized with the gears, and the rotation direction can be read through the square wave sequence. In this embodiment, the Hall unit can also perform self-calibration of the offset voltage. The chip's active offset voltage distortion mainly occurs when the measured magnetic field is not perpendicular to the measurement plane and is not parallel to the normal. At this time, both the pre-biased magnetic field and the re-magnetized gear magnetic field deviate from the parameters in the magnetic circuit design. The mathematical model is the " " is multiplied by the sine of the angle. Since the polarity of the offset voltage does not change periodically with the orthogonal reversal of the current, the polarity of the injected current of the first unit 401, the second unit 402, the third unit 403 and the fourth unit 404 is injected once in each positive direction, such as Figure 3 As shown, the Hall voltage signal with offset voltage and periodic polarity changes, which is sent to the subsequent circuit through the first unit 401, the second unit 402, the third unit 403 and the fourth unit 404, can filter the offset voltage under the action of the filter, and then drive the final output after Schmitt trigger debouncing and shaping; Taking the first unit 401 and the third unit 403 as an example, Figure 4 As shown in Figure 1, the mathematical representation of offset voltage self-calibration is: the vector product of any pair of perpendicular vectors is zero, cos90°=0, and the polarity of the output Hall voltage signal will also change periodically. Operational amplifiers A1, A2, B1, and B2 are all temperature-compensated amplifiers. Combined with offset voltage self-calibration, they can ensure stable operation within the supply voltage range and achieve accurate measurement.

[0025] How it works When the measured transmission wheel passes through the first unit 401, the square wave of the A-phase measurement channel 5 is pulled low; when passing through the second unit 402, the square wave of the B-phase measurement channel 7 is pulled high; when passing through the third unit 403, the square wave of the A-phase measurement channel 5 is pulled low; when passing through the fourth unit 404, the square wave of the B-phase measurement channel 7 is pulled low. The Hall voltage signal mixed with the offset voltage and with periodic polarity changes in the subsequent circuit is sent through the first unit 401, the second unit 402, the third unit 403 and the fourth unit 404 and is transmitted to the first filter 604 and the second filter 804. The Hall voltage signal has the offset voltage removed in the first filter 604 and the second filter 804, and then undergoes Schmitt trigger debouncing and shaping to drive the final output.

[0026] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A gear orthogonal output speed measuring device based on Hall element, characterized in that: include: housing (1); A bracket (2) is provided in the housing (1); A permanent magnet (3) is provided on the bracket (2) and is used to generate a stable magnetic field; The IC (4) is arranged on the bracket (2), and includes a plurality of arrayed Hall units for responding at different points to the changing differential magnetic field generated by the rotating annular magnet and the iron target coupled to the magnet during rotation, an operational amplifier connected to the Hall unit, a filter connected to the operational amplifier, a Schmitt trigger connected to the filter, and a drive gate circuit (9) connected to the Schmitt trigger.

2. The gear orthogonal output speed measuring device based on Hall element according to claim 1, characterized in that: The Hall unit includes a first unit (401), a second unit (402), a third unit (403) and a fourth unit (404); The first unit (401) and the third unit (403) have quadrature outputs and form an A-phase measurement channel (5) corresponding to the second unit (402); The second unit (402) and the fourth unit (404) have quadrature outputs and form a B-phase measurement channel (7) corresponding to the third unit (403).

3. The gear orthogonal output speed measuring device based on Hall element according to claim 1, characterized in that: The material of the bracket (2) includes modified plastic of glass fiber and black masterbatch.

4. The gear orthogonal output speed measuring device based on Hall element according to claim 1, characterized in that: A potting structure is also provided between the housing (1) and the bracket (2), and the potting structure comprises epoxy potting glue 9002.

5. The gear orthogonal output speed measuring device based on Hall element according to claim 2, characterized in that: The first unit (401), the second unit (402), the third unit (403) and the fourth unit (404) are arranged at equal intervals.

6. The gear orthogonal output speed measuring device based on Hall element according to claim 2, characterized in that: The distance between the geometric center of the A-phase measurement channel (5) and the geometric center of the B-phase measurement channel (7) is .

7. The gear orthogonal output speed measuring device based on Hall element according to claim 6, characterized in that: The signal polarity of the A-phase measurement channel (5) is opposite to the signal polarity of the B-phase measurement channel (7).

8. The gear orthogonal output speed measuring device based on Hall element according to claim 7, characterized in that: When the measured transmission wheel passes through the first unit (401), the square wave of the A-phase measurement channel (5) is pulled low; when passing through the second unit (402), the square wave of the B-phase measurement channel (7) is pulled high; when passing through the third unit (403), the square wave of the A-phase measurement channel (5) is pulled low; when passing through the fourth unit (404), the square wave of the B-phase measurement channel (7) is pulled low.

9. The gear orthogonal output speed measuring device based on Hall element according to claim 6, characterized in that: The output end of the first unit (401) is connected to an operational amplifier A1 (601), the output end of the third unit (403) is connected to an operational amplifier A2 (602), the output ends of the operational amplifier A1 (601) and the operational amplifier A2 (602) are connected to a first operational amplifier (603), the output end of the first operational amplifier (603) is connected to a first filter (604), the output end of the first filter (604) is connected to a first Schmitt trigger (605), and the first Schmitt trigger (605) is connected to a driving gate circuit (9).

10. The gear orthogonal output speed measuring device based on Hall element according to claim 6, characterized in that: The output end of the second unit (402) is connected to an operational amplifier B1 (801), the output end of the fourth unit (404) is connected to an operational amplifier B2 (802), the output ends of the operational amplifier B1 (801) and the operational amplifier B2 (802) are connected to a second operational amplifier (803), the output end of the second operational amplifier (803) is connected to a second filter (804), the output end of the second filter (804) is connected to a second Schmitt trigger (805), and the second Schmitt trigger (805) is connected to a driving gate circuit (9).

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