CN108414785B - Sensor and detection device - Google Patents
Sensor and detection device Download PDFInfo
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- CN108414785B CN108414785B CN201810417142.6A CN201810417142A CN108414785B CN 108414785 B CN108414785 B CN 108414785B CN 201810417142 A CN201810417142 A CN 201810417142A CN 108414785 B CN108414785 B CN 108414785B
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P3/00—Measuring linear or angular speed; Measuring differences of linear or angular speeds
- G01P3/42—Devices characterised by the use of electric or magnetic means
- G01P3/44—Devices characterised by the use of electric or magnetic means for measuring angular speed
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P13/00—Indicating or recording presence, absence, or direction, of movement
- G01P13/02—Indicating direction only, e.g. by weather vane
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- Transmission And Conversion Of Sensor Element Output (AREA)
Abstract
The application provides a sensor and a detection device, which relate to the technical field of industrial application and comprise an assembly circuit board, a magnetic component and a shell for fixing the assembly circuit board and the magnetic component; the shell is sleeved on the target object so that the target object drives the magnetic component to rotate; the magnetic component is used for providing a triggering magnetic field for the assembly circuit board; the assembly circuit board is used for outputting square wave signals according to the triggering magnetic field and sending the square wave signals to the controller so that the controller can detect the rotating direction and the speed of the target object through the square wave signals.
Description
Technical Field
The invention relates to the technical field of industrial application, in particular to a sensor and a detection device.
Background
According to the detection principle, currently, a hall sensor integrated with one hall speed band direction chip or two hall switch chips is commonly used to measure the speed and direction of a rotating object at the same time.
Meanwhile, the two schemes are matched with each other and are respectively a magnetic encoder or a ferromagnetic signal wheel. The former is injection molding magnetism, so the mold and unit price are high, and the magnetizing mold is complex in design. Secondly, as the design is shaped, the flexibility of changing the number of magnetic poles to adapt to different demands is lacking; the latter has a large volume of signal wheel and requires mounting or integrating magnets behind the chip, with a consequent increase in system costs.
Disclosure of Invention
In view of the above, it is an object of the present invention to provide a sensor and a detection device, which provide a sensor with a smaller volume and a lower cost for simultaneously measuring the direction and the speed of a rotating object.
In a first aspect, embodiments of the present invention provide a sensor comprising an assembly circuit board, a magnetic component, and a housing for securing the assembly circuit board and the magnetic component;
The shell is sleeved on the target object so that the target object drives the magnetic assembly to rotate;
the magnetic component is used for providing a triggering magnetic field for the assembly circuit board;
The assembly circuit board is used for outputting square wave signals according to the triggering magnetic field and sending the square wave signals to the controller so that the controller can detect the rotating direction and the rotating speed of the target object through the square wave signals.
With reference to the first aspect, the embodiment of the present invention provides a first possible implementation manner of the first aspect, wherein the magnetic assembly includes a plurality of magnets and a magnet plastic housing for fixing the plurality of magnets, wherein the magnet plastic housing equally spaces the magnets.
With reference to the first aspect, the embodiment of the present invention provides a second possible implementation manner of the first aspect, wherein the assembly circuit board outputs different square wave signals according to different trigger magnetic fields generated by the magnetic components, wherein different numbers of magnetic components of the magnet generate different trigger magnetic fields, and different rotation speeds and directions of the target object generate different trigger magnetic fields.
With reference to the first aspect, an embodiment of the present invention provides a third possible implementation manner of the first aspect, wherein the magnetic component increases a difference between a duty cycle of the square wave signal output by the assembly circuit board when the target object rotates forward and a duty cycle of the square wave signal output by the assembly circuit board when the target object rotates backward by reducing the trigger magnetic field generated by the number of magnets.
With reference to the first aspect, the embodiment of the present invention provides a fourth possible implementation manner of the first aspect, wherein the assembly circuit board includes a magnetic switch chip, a capacitor C, a resistor R1, a light emitting diode LED, and a load resistor R2;
The input end of the magnetic switch chip is respectively connected with a power supply VCC and one end of the capacitor C, the other end of the capacitor C is grounded, and the output end of the magnetic switch chip is respectively connected with one ends of the resistor R1 and the load resistor R2; the other end of the resistor R1 is connected with the positive electrode of the light-emitting diode LED, the negative electrode of the light-emitting diode LED is grounded, the other end of the load resistor R2 is grounded, and the grounding end of the magnetic switch chip is connected with the negative electrode of the light-emitting diode LED.
With reference to the first aspect, an embodiment of the present invention provides a fifth possible implementation manner of the first aspect, where the magnetic assembly is detachably connected to the housing, and the magnetic assemblies with different numbers of magnets may be detachably assembled with the housing.
With reference to the first aspect, an embodiment of the present invention provides a sixth possible implementation manner of the first aspect, where the device further includes a wire harness and a sealing assembly;
the wire harness is connected with the assembly circuit board and used for providing electric energy for the assembly circuit board and sending the square wave signal to the controller;
the sealing assembly is respectively arranged at the connection position of the wire harness and the shell and the connection position of the shell and the target object and is used for dust prevention and water prevention.
With reference to the first aspect, the embodiment of the present invention provides a seventh possible implementation manner of the first aspect, wherein the magnetic assembly and the inner ring of the housing are fixed and limited in an axial direction by a buckle.
In a second aspect, an embodiment of the present invention further provides a detection apparatus, including the sensor as described above, and further including a controller connected to the sensor, configured to receive a square wave signal sent by the sensor, and analyze the square wave signal to obtain a rotation direction and a speed of a target object.
With reference to the second aspect, the embodiment of the present invention provides a first possible implementation manner of the second aspect, wherein the controller learns a rotation direction of the target object according to a duty cycle of the square wave signal, and learns a speed of the target object according to a preset level number of the square wave signal in a preset time.
The embodiment of the application provides a sensor and a detection device, which comprises an assembly circuit board, a magnetic component and a shell for fixing the assembly circuit board and the magnetic component; the shell is sleeved on the target object so that the target object drives the magnetic component to rotate; the magnetic component is used for providing a triggering magnetic field for the assembly circuit board; the assembly circuit board is used for outputting square wave signals according to the triggering magnetic field and sending the square wave signals to the controller so that the controller can detect the rotating direction and the speed of the target object through the square wave signals.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
In order to make the above objects, features and advantages of the present invention more comprehensible, preferred embodiments accompanied with figures are described in detail below.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present invention, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic diagram of a sensor structure according to an embodiment of the present invention;
FIG. 2 is an exploded view of a sensor according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of a sensor waveform according to an embodiment of the present invention;
FIG. 4 is a schematic circuit diagram of an assembly circuit board in a sensor according to an embodiment of the present invention;
Fig. 5 is a schematic diagram of the appearance of a sensor according to an embodiment of the present invention.
Icon: 1-a housing; 2-a magnet plastic housing; 3-magnet; 4-an assembly circuit board; a 5-plastic cover; 6-a rubber sealing ring; 7-sealing and plugging the wire harness; 8-wire harness; 9-magnetic assembly.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Magnetic hall sensors currently in common use for measuring the speed and direction of a rotating object are typically implemented in several ways:
The hall sensor uses two hall switch chips, and the chips are arranged at an angle on the circuit board. When the gear or the magnetic encoder rotates, the rotation speed of the gear is measured by counting the pulse number in a certain time, and the direction detection is performed according to the phase relation of the two signal outputs. The two paths of signal output are defined as A and B, the phase difference of the A signal is advanced by 90 degrees compared with the phase difference of the B signal when forward transmission is carried out, and the phase difference of the B signal is advanced by 90 degrees when reverse transmission is carried out, so that the rotation direction can be detected;
the Hall sensor uses an integrated Hall speed belt direction chip, and at the moment, two or three Hall units which are arranged at intervals are still arranged in the chip. When the gear or the magnetic encoder rotates, the rotation speed of the gear is obtained by counting the pulse number in a certain time. Regarding direction detection, the direction detection is judged by different pulse widths in forward and reverse directions, for example, the pulse width is 45 mu s in the forward transmission case and the pulse width is 90 mu s in the reverse rotation case;
The disadvantage of both of the above techniques is the high cost of the system of sensors and magnetic encoders, the lack of varying flexibility. Currently the mainstream solution uses at least two hall switches or one integrated speed direction chip. Hall chips are a major cost source for sensors, accounting for more than half of the total material cost. Therefore, it has been a design goal to reduce the number of chips to achieve high cost performance speed and direction detection; for the latter, the chip itself is more complex, and besides 2-3 differential hall cells, there are dedicated circuits and the like responsible for processing signals, so that the cost of the hall chip is higher than that of two hall switches in the former.
Based on the above, the sensor and the detection device provided by the embodiment of the invention can be used for simultaneously measuring the direction and the speed of the rotating object by using the sensor with smaller volume and lower cost.
The following is a detailed description of examples.
Fig. 1 is a schematic diagram of a sensor structure according to an embodiment of the present invention.
Referring to fig. 1, the sensor includes an assembly circuit board 4, a magnetic component 9, and a housing 1 for fixing the assembly circuit board 4 and the magnetic component 9;
the shell 1 is sleeved on the target object so that the target object drives the magnetic component 9 to rotate;
The magnetic component 9 is used for providing a triggering magnetic field for the assembly circuit board 4;
The assembly circuit board 4 is used for outputting a square wave signal according to the triggering magnetic field and sending the square wave signal to the controller so that the controller can detect the rotating direction and the rotating speed of the target object through the square wave signal.
Specifically, the sensor provided by the application has compact modular design, is installed through holes, and is easy to integrate with the application to be tested, such as a bearing, a motor and other target objects. Different from shaft end detection, the sensor is sleeved on the target object without extra space, so that the detection of the rotating speed and the rotating direction of the target object can be realized, the volume is small, and the cost is saved, and is particularly shown in fig. 5;
The sensor is a plastic shell and is used for fixing an Assembly circuit board 4 (PCBA, printed Circuit Board +assembly), and provides a closed space of packaging materials against external mechanical external force so as to protect electronic components;
Further, as shown in fig. 2, the magnetic assembly 9 includes a plurality of magnets 3 and a magnet plastic housing 2 for fixing the plurality of magnets 3, wherein the magnet plastic housing 2 equally spaces the magnets 3. The magnet plastic shell 2 is used for providing external protection for the magnet 3, and equidistantly spacing the magnet 3, the magnet 3 has the function of generating a magnetic field for triggering the magnetic switch chip in the assembly circuit board 4 to work, and the chip senses different magnetic field intensities by outputting different magnetic curves so as to trigger the change of the working state of the chip;
Here, the principle of the magnetic encoder is explained by way of examples of 8 magnets 3 and 12 magnets 3. The difference between 8 magnets 3 and 12 magnets 3 is mainly represented by the difference in the spacing distance between adjacent magnets 3, and the spacing distance of 8 magnets 3 is larger. Further, the magnetic switch chip on the assembly circuit board 4 outputs different square wave signals according to different trigger magnetic fields generated by the magnetic components 9, wherein the magnetic components 9 with different numbers of the magnets 3 generate different characteristic trigger magnetic fields which change periodically, and the target object generates different trigger magnetic fields with different rotation speeds and directions.
When the magnetic component 9 rotates (driven by a shaft or other driving elements), the magnetic switch chip on the assembly circuit board 4 is affected by the changing magnetic field of the magnetic component 9, so that the sensor outputs continuous square wave signals with fixed duty ratio, the sensor transmits the generated square wave signals to the controller, and the controller analyzes the square wave signals to further obtain the rotating direction and speed of the target object;
The installation of the magnet 3 and the sensor is compact in mechanical design, the magnetic assembly 9 and the inner ring of the sensor shell 1 are fixed and limited in the axial direction through the buckle, so that the magnetic assembly 9 is only allowed to circularly rotate, the sensor is smaller in size due to the design, the product yield is higher due to the one-to-one installation mode of the sensor and the magnetic assembly 9, and the possibility of failure or faults of the product in the use process is reduced.
Further, the magnetic component 9 increases the difference between the duty ratio of the square wave signal output by the assembly circuit board 4 when the target object is rotated forward and the duty ratio of the square wave signal output when the target object is rotated backward by reducing the trigger magnetic field generated by the number of magnets.
Specifically, if the number of magnets 3 is increased, the duty ratio of the forward rotation or the reverse rotation will be close to 50%, i.e., the duty ratios of the forward rotation and the reverse rotation are equally distributed; but if the number of magnets 3 is reduced the forward or reverse sensor output duty cycle will be 50% away. For example, if the number of magnets 3 reaches 12, the duty ratio is about 46% in the forward direction and about 54% in the reverse direction. At this time, when the number of magnets 3 is reduced to 10, the forward rotation duty ratio is about 42% and the reverse rotation duty ratio is about 58%. For the same part, the sum of the forward rotation and reverse rotation duty ratios is 100%;
the difference between the duty ratios of the positive and negative rotation square wave signals is increased, so that the recognition capability of the controller on the square wave signals is more outstanding, and the recognition on the rotation direction of the target object is more accurate;
further, the magnetic assembly 9 is detachably connected with the housing 1, and the magnetic assemblies 9 with different numbers of magnets can be detached and assembled with the housing 1.
Here, according to different practical situations, the magnetic assemblies 9 with different numbers of magnets may need to be matched, at this time, if the cost of replacing different sensors is higher, the magnetic assemblies 9 with different numbers of magnets meeting the requirements can be assembled and disassembled with the shell 1, so that the sensor meeting the requirements is obtained, and the cost is saved;
In addition, the embodiment of the invention provides a simplified magnetic circuit design, eliminates an injection-molded magnet encoder, uses small magnets convenient to install to assemble a magnetic assembly 9, and realizes flexible adjustment of different duty ratios by controlling the positions of adjacent magnets;
Further, as shown in fig. 4, the assembly circuit board 4 includes a magnetic switch chip, a capacitor C, a resistor R1, a light emitting diode LED, and a load resistor R2;
The input end of the magnetic switch chip is respectively connected with one end of a power supply VCC and one end of a capacitor C, the other end of the capacitor C is grounded, and the output end of the magnetic switch chip is respectively connected with one ends of a resistor R1 and a load resistor R2; the other end of the resistor R1 is connected with the anode of the light-emitting diode LED, the cathode of the light-emitting diode LED is grounded, the other end of the load resistor R2 is grounded, and the grounding end of the magnetic switch chip is connected with the cathode of the light-emitting diode LED.
Here, the components on the assembly circuit board 4 are soldered to the circuit board by SMT (Surface Mount Technology ) equipment patches, and then the circuit board assembly is soldered with the wiring harness 8. The circuit inputs and is 5V direct current, and the output is square wave signal, and the high level is: 3.4-4.2V, and the output low level is 0-0.5V;
wherein, the adjustment of the output voltage value can be realized by adjusting the parameter values of the components such as the resistor in the circuit, and the output level value is only an example and is not limited to the example;
the PCBA circuit board subassembly is used for providing an installation carrier of electronic components and providing a circuit and also comprises an EMC (electromagnetic compatibility) protection function;
the application adopts the non-contact magnetic induction principle, only uses low cost, and judges the forward and reverse rotation of the rotating shaft through the different output duty ratio of one magnetic switch chip (switch chips such as Hall, AMR, GMR, TMR and the like);
here, the magnetic switch chip is preferably a hall chip;
according to the application, the optimal arrangement of the chip and the magnetic field switching point analysis result is obtained through software simulation, and a simplified circuit design is adopted, so that only one chip is needed, and a complex operation circuit or processor is not needed;
further, the light emitting diode LED is used for displaying the working state of the sensor.
The Light Emitting Diode (LED) is welded on the circuit board, and each magnet (3) rotates to trigger the LED to flash, so that whether the sensor is in a normal working state or not is judged;
here, the light emitting diode LED, the magnetic switch chip are soldered on the assembly circuit board 4, not shown in fig. 2;
The sensor provided by the embodiment of the application further comprises a plastic cover 5, which is used for sealing and protecting the sensor, and sealing the opening of the plastic shell of the sensor, thereby protecting electronic devices such as an assembly circuit board 4 and the like;
Further, a harness 8 is connected to the assembly circuit board 4, and is used for providing electric energy for the assembly circuit board 4 and sending square wave signals to the controller.
Here, the wiring harness 8 (including the connector) is used to supply the voltage required for the sensor to operate and to transmit the sensor output signal to the controller;
further, the device also comprises a dustproof and waterproof sealing assembly which is respectively arranged at the connection position of the wire harness 8 and the shell 1 and the connection position of the shell 1 and the target object.
The sealing assembly comprises a rubber sealing ring 6 arranged at the connection position of the shell 1 and the target object, and a wire harness sealing plug 7 arranged at the connection position of a wire harness 8 and the shell 1;
Further, the embodiment of the invention also provides a detection device which comprises the sensor and a controller connected with the sensor, wherein the controller is used for receiving square wave signals sent by the sensor and analyzing the square wave signals to acquire the rotation direction and the speed of the target object. Further, the controller knows the rotation direction of the target object according to the duty ratio of the square wave signal, and knows the speed of the target object through the preset level number of the square wave signal in the preset time.
According to the embodiment of the invention, the judgment of the rotation direction is realized by enlarging the duty ratio mode of forward and reverse rotation;
Specifically, the controller calculates the rotation speed of the target object through the frequency of the square wave; whether the target object is forward or reverse is judged by whether the duty ratio of the square wave is lower than 50% or higher than 50%. It is conceivable that if the number of magnets is too large, the duty ratio is 50% regardless of the forward rotation or the reverse rotation, and it is impossible to determine whether the magnets are forward or reverse, so that the number of magnets is reduced to increase the duty ratio value of the forward rotation or the reverse rotation, and the controller can identify whether the magnets are forward rotation or reverse rotation;
Here, the controller may learn the speed of the target object by detecting the number of high levels or low levels within a preset fixed time;
The embodiment of the invention provides a low-cost Hall switch type sensor, which is provided with a magnetic encoder with an increased or decreased number, so that a low-cost system solution with an adjustable duty ratio is realized, the sensor only uses one bipolar latch type Hall switch, and the aim of detecting the rotation direction through different duty ratios is realized through forward rotation and reverse rotation of a magnetic component encoder with a specific design, therefore, the invention relates to the matching of two parts of the sensor and a magnetic wheel.
As shown in fig. 3, if the curve a in fig. 3a is characterized by positive rotation of the magnetic encoder in the positive direction of the magnetic field intensity B axis, the bipolar latch type hall switch is characterized in that when the positive magnetic field (for example, N pole) reaches a certain triggering magnetic field value, the hall switch is triggered to a low level state (i.e., square wave mn segment), and the low level state is kept all the time, as the magnetic encoder rotates until the magnetic field reaches the same magnetic field triggering value in the reverse direction (for example, S pole), at this time, the curve a is in the negative direction of the magnetization M axis, and the square wave level state is turned to a high level. Until the next N-pole magnetic field is triggered again, thereby reciprocating.
In addition, the magnetic field between adjacent magnets changes to sine and cosine curves periodically alternating. When the number of magnets is small, the distance between adjacent magnets is far, so that the adjacent positions of the magnetic field curves are gentle, as shown by the curve a in fig. 3 a; when the number of magnets is large, the distance between adjacent magnets is relatively short, so that the magnetic field curve is relatively steep adjacent to each other, as shown by the b curve in fig. 3 b. The data difference in duty cycle is the percentage difference of T high/T.
By utilizing the method, the duty ratio value of forward rotation can be controlled by adjusting the number of different magnets, namely, the theoretical duty ratio value is 50% when the number of the magnets is large. However, if the number of magnets is reduced, it is possible to increase or decrease the duty cycle (i.e., to increase the difference in the forward and reverse duty cycles) by, for example, 30% or 70% (depending on the north and south arrangement direction of the magnets).
Normally, if the magnets are closely arranged circumferentially, the duty cycle should be infinitely close to 50%. However, as shown in fig. 3, the chip is bipolar latch, so the magnetic field that triggers the operation of the chip must be the next adjacent magnetic field of the same magnitude but opposite polarity. The number of 8 magnets is small relative to 10 magnets, so for a small number of magnets, the time elapsed from point n to point p is longer than the number of magnets (i.e., left plot t high is longer than right plot t high), so the duty cycle of fig. 3a is greater than that of fig. 3b, i.e., the duty cycle can be adjusted by the number of magnets;
when the magnetic switch chip is placed on the front side, the magnetic switch chip is set to rotate clockwise, at the moment, the duty ratio in forward rotation is smaller than the duty ratio in reverse rotation (the specific situation still needs to be determined according to whether the chip patch is on the front side or the reverse side of the circuit board), the duty ratios in forward rotation and reverse rotation are complementary, the duty ratio in forward rotation is added to 100%, the duty ratio in forward rotation is 35% -45%, and the duty ratio in reverse rotation is 65% -55%;
By utilizing the difference of the forward duty ratio and the reverse duty ratio, the detection and judgment of the rotation direction of the motor can be realized. The controller may set the duty cycle of the acquired square wave to 30% for forward and 70% for reverse rotation. The application omits the cost of at least one Hall chip, related circuits and signal wires, and simplifies the design difficulty of the controller.
The embodiment of the invention is a low-cost Hall switch type sensor combined with a low-cost magnetic component encoder, can be applied to assisting a pedal coaxial motor of a booster bicycle, has the advantages of high measurement precision, quick response time, simple process, long service life, capability of working in an environment with high temperature and greasy dirt, simple circuit design, no involvement of a decoding chip and ingenious implementation mode, and simultaneously has the advantages of high measurement precision, quick response time, less research and development investment and low cost.
The detection device provided by the embodiment of the invention has the same technical characteristics as the sensor provided by the embodiment, so that the same technical problems can be solved, and the same technical effects can be achieved.
In the description of embodiments of the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.
In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. The above-described apparatus embodiments are merely illustrative, for example, the division of the units is merely a logical function division, and there may be other manners of division in actual implementation, and for example, multiple units or components may be combined or integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be through some communication interface, device or unit indirect coupling or communication connection, which may be in electrical, mechanical or other form.
The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of 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.
In addition, each functional unit in the embodiments of the present invention may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit.
Finally, it should be noted that: the above examples are only specific embodiments of the present invention, and are not intended to limit the scope of the present invention, but it should be understood by those skilled in the art that the present invention is not limited thereto, and that the present invention is described in detail with reference to the foregoing examples: any person skilled in the art may modify or easily conceive of the technical solution described in the foregoing embodiments, or perform equivalent substitution of some of the technical features, while remaining within the technical scope of the present disclosure; such modifications, changes or substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention, and are intended to be included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (7)
1. A sensor, comprising an assembly circuit board, a magnetic component and a shell for fixing the assembly circuit board and the magnetic component;
The shell is sleeved on the target object so that the target object drives the magnetic assembly to rotate;
the magnetic component is used for providing a triggering magnetic field for the assembly circuit board;
The assembly circuit board is used for outputting a square wave signal according to the trigger magnetic field and sending the square wave signal to the controller so that the controller can detect the rotating direction and the rotating speed of the target object through the square wave signal;
The magnetic component increases the difference between the duty ratio of the square wave signal output by the assembly circuit board when the target object rotates positively and the duty ratio of the square wave signal output by the assembly circuit board when the target object rotates negatively by reducing the triggering magnetic field generated by the number of magnets;
the magnetic assembly comprises a plurality of magnets and a magnet plastic housing for fixing the plurality of magnets, wherein the magnet plastic housing equally spaces the magnets;
the magnetic components are detachably connected with the shell, and the magnetic components with different numbers of magnets can be detached and assembled with the shell.
2. The sensor of claim 1, wherein the assembly circuit board outputs different square wave signals according to different trigger magnetic fields generated by the magnetic components, wherein different numbers of magnets of the magnetic components generate different trigger magnetic fields, and different rotation speeds and directions of the target object generate different trigger magnetic fields.
3. The sensor of claim 1, wherein the assembly circuit board comprises a magnetic switch chip, a capacitor C, a resistor R1, a light emitting diode LED, and a load resistor R2;
The input end of the magnetic switch chip is respectively connected with a power supply VCC and one end of the capacitor C, the other end of the capacitor C is grounded, and the output end of the magnetic switch chip is respectively connected with one ends of the resistor R1 and the load resistor R2; the other end of the resistor R1 is connected with the positive electrode of the light-emitting diode LED, the negative electrode of the light-emitting diode LED is grounded, the other end of the load resistor R2 is grounded, and the grounding end of the magnetic switch chip is connected with the negative electrode of the light-emitting diode LED.
4. The sensor of claim 1, further comprising a wire harness and a seal assembly;
the wire harness is connected with the assembly circuit board and used for providing electric energy for the assembly circuit board and sending the square wave signal to the controller;
the sealing assembly is respectively arranged at the connection position of the wire harness and the shell and the connection position of the shell and the target object and is used for dust prevention and water prevention.
5. The sensor of claim 4, wherein the magnetic assembly is axially fixed and retained with the inner ring of the housing by a snap fit.
6. A detection device, characterized by comprising the sensor according to any one of claims 1-5, and further comprising a controller connected to the sensor, for receiving the square wave signal sent by the sensor, and analyzing the square wave signal to obtain the rotation direction and speed of the target object.
7. The apparatus according to claim 6, wherein the controller knows the rotation direction of the target object from the duty ratio of the square wave signal and knows the speed of the target object from the preset number of levels of the square wave signal in a preset time.
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| CN111273053B (en) * | 2020-01-22 | 2022-11-01 | 武汉船用机械有限责任公司 | Rotating speed measuring device for motor |
| CN112067995A (en) * | 2020-09-11 | 2020-12-11 | 广东美的暖通设备有限公司 | Detection device and detection method of magnetic suspension motor and magnetic suspension motor |
| CN113405562A (en) * | 2021-06-18 | 2021-09-17 | 广东工业大学 | Mileage measurement system and method based on magnetic sensor |
| CN113659879A (en) * | 2021-07-26 | 2021-11-16 | 极限人工智能有限公司 | Motor closed-loop control device and method for surgical robot |
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