Motor encoder drive circuit, motor and sensor

Abstract

The application provides a motor encoder driving circuit, a motor and a sensor, wherein the motor encoder driving circuit comprises: a photoelectric coupler comprising an input side and an output side; and a driving current adjusting circuit connected between the input side and the output side of the photoelectric coupler and used for adjusting the driving current of the input side according to the output voltage of the output side. The application sets the driving current adjusting circuit between the input side and the output side of the photoelectric coupler, thereby obtaining a motor encoder driving circuit capable of adjusting the driving current of the input side according to the output voltage of the output side. In the circuit, the driving current adjusting circuit adjusts the driving current of the input side according to the output voltage of the output side, so that the influence of temperature change on the output of the photoelectric coupler can be perceived through the change of the output voltage of the output side, and then the influence of temperature change on the position detection accuracy of the photoelectric coupler can be overcome by controlling the driving current of the photoelectric coupler.

Description

Technical Field

[0001] This application relates to the field of sensor technology, and in particular to a motor encoder drive circuit, a motor, and a sensor. Background Technology

[0002] High-precision motor control requires accurate detection of the motor's position. Optical couplers, as a low-cost solution, are widely used for motor position detection. (For example, an optical coupler encoder includes an optical coupler transmitter, an optical coupler receiver, and a code disk with alternating black and white teeth. When light emitted from the optical coupler transmitter shines on the white teeth of the code disk, the high reflectivity of the white teeth causes the light to return to the optical coupler receiver, generating a significant current. When light from the optical coupler transmitter shines on the black teeth of the code disk, the low reflectivity of the black teeth causes the light to be absorbed, and the receiver does not receive the light, thus not generating a large current. By detecting the current at the receiver, the black and white teeth of the code disk can be determined. During motor operation, the position is determined by knowing how many white and black teeth the motor has passed.) However, the luminous intensity of the optical coupler is affected by temperature changes, which leads to a decrease in the position detection accuracy of the optical coupler with temperature variations. Utility Model Content

[0003] To address at least one technical problem existing in the prior art, this application proposes a motor encoder drive circuit, a motor, and a sensor.

[0004] In a first aspect, this application provides a motor encoder drive circuit, which includes:

[0005] An optocoupler includes an input side and an output side;

[0006] A drive current adjustment circuit is connected between the input and output sides of the optocoupler and is used to adjust the drive current on the input side according to the output voltage on the output side.

[0007] In some embodiments, the drive current regulation circuit includes: a constant current source and a controller sequentially connected between the input side and the output side; the controller is used to control the drive current of the constant current source according to the output voltage of the output side.

[0008] In some embodiments, the drive current regulation circuit further includes a feedback voltage detection circuit disposed between the controller and the output side of the optocoupler, the feedback voltage detection circuit including an operational amplifier.

[0009] In some embodiments, the input side of the optocoupler includes a first connection terminal and a second connection terminal; the output side of the optocoupler includes a third connection terminal and a fourth connection terminal; wherein...

[0010] The first connection terminal is connected to a first voltage, and the constant current source is connected between the second connection terminal and the power supply ground; or, the constant current source is connected between the first voltage and the first connection terminal, and the second connection terminal is connected to the power supply ground; the control terminal of the controller is connected to the constant current source to adjust the drive current of the constant current source.

[0011] The third connection terminal is connected to the second voltage, the fourth connection terminal is connected to the power supply ground, and the third connection terminal is connected to the positive input terminal of the operational amplifier; the output terminal of the operational amplifier is connected to the input terminal of the controller and the negative input terminal of the operational amplifier, or the output terminal of the operational amplifier is connected to the negative input terminal of the operational amplifier through a first resistor, and the negative input terminal of the operational amplifier is connected to the power supply ground through a second resistor.

[0012] In some embodiments, a third resistor is provided between the second voltage and the third connection terminal.

[0013] In some embodiments, the resistance value of the third resistor is in the range of 2K~5K.

[0014] In some embodiments, the input side of the optocoupler includes an LED element, the input terminal of which is configured as the first connection terminal, and the output terminal of which is configured as the second connection terminal.

[0015] In some embodiments, the output side of the optocoupler includes a photosensitive element, the input end of which is configured as a third connection end, and the output end of which is configured as a fourth connection end.

[0016] Secondly, this application also provides a motor that includes the motor encoder drive circuit described in any embodiment of this application.

[0017] Thirdly, this application also provides a sensor that includes the motor described in any embodiment of this application.

[0018] This application provides a motor encoder drive circuit that adjusts the drive current on the input side based on the output voltage of the output side by setting a drive current adjustment circuit between the input and output sides of the optocoupler. Based on this circuit, only appropriate configuration of the drive current adjustment circuit is needed to enable it to adjust the drive current on the input side according to the output voltage. This allows the influence of temperature changes on the optocoupler output to be sensed through changes in the output voltage, and thus the influence of temperature changes on the position detection accuracy of the optocoupler can be overcome by controlling the drive current of the optocoupler. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a circuit schematic diagram of one embodiment of the motor encoder drive circuit of this application;

[0021] Figure 2 This is a circuit schematic diagram of another embodiment of the motor encoder drive circuit of this application;

[0022] Figure 3 This is a circuit schematic diagram of another embodiment of the motor encoder drive circuit of this application;

[0023] Figure 4 This is a circuit schematic diagram of another embodiment of the optocoupler in this application;

[0024] Figure 5 This is a circuit schematic diagram of another embodiment of the optocoupler in this application;

[0025] Figure 6 This is a circuit schematic diagram of another embodiment of the optocoupler in this application;

[0026] Figure 7 This is a circuit schematic diagram of another embodiment of the optocoupler in this application. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0028] This application provides a motor encoder drive circuit, comprising: an optocoupler including an input side and an output side; and a drive current adjustment circuit connected between the input side and the output side of the optocoupler, used to adjust the drive current of the input side according to the output voltage of the output side. The optocoupler includes an LED element and a photosensitive element, wherein the LED element emits light under the drive current and illuminates the photosensitive element, thereby forming an output voltage at the output terminal of the photosensitive element.

[0029] This application provides a motor encoder drive circuit capable of adjusting the input drive current based on the output voltage of the output side by incorporating a drive current adjustment circuit between the input and output sides of the optocoupler. Those skilled in the art can appropriately configure the drive current adjustment circuit to adjust the input drive current according to the output voltage. This allows the circuit to sense the influence of temperature changes on the optocoupler output by monitoring changes in the output voltage, and subsequently overcome the impact of temperature changes on the position detection accuracy of the optocoupler by controlling the drive current of the optocoupler.

[0030] In some embodiments, the drive current regulation circuit includes: a constant current source and a controller sequentially connected between the input side and the output side; the controller is used to control the drive current of the constant current source according to the output voltage of the output side. Exemplarily, the controller is a main control IC. Those skilled in the art can configure the controller appropriately to enable the drive current regulation circuit to adjust the drive current on the input side according to the output voltage of the output side, thereby achieving the purpose of overcoming the influence of optocoupler temperature changes on the optocoupler position detection accuracy by controlling the drive current of the optocoupler.

[0031] In some embodiments, the software configuration logic may be as follows: the output voltage is Vout. When temperature changes cause the light intensity of the optocoupler to increase, Vout will decrease. The main control IC detects the decrease in Vout and adjusts the current of the constant current source to decrease. The light intensity of the optocoupler weakens, and Vout increases. The adjustment stops when Vout rises to its initial value. Conversely, when temperature causes the light intensity of the optocoupler to decrease, the main control IC adjusts in the opposite direction.

[0032] It should be noted that the above software configuration logic is merely an example, and this application does not impose any limitations on it. Furthermore, based on the motor encoder drive circuit of this application, users can configure the software as needed to adjust the drive current on the input side according to the output voltage on the output side of the optocoupler, thereby achieving the purpose of overcoming the influence of optocoupler temperature changes on the position detection accuracy of the optocoupler by controlling the drive current of the optocoupler.

[0033] Furthermore, the inventors discovered during the development of this application that traditional encoders with built-in temperature compensation are extremely expensive, making them difficult to widely apply in low-cost design schemes. Moreover, they directly detect temperature to predict changes in light intensity, constituting open-loop control. In contrast, this application uses an external main control IC to monitor the current intensity at the receiving end to determine the intensity of the luminous power, thereby achieving feedback-based closed-loop control and reducing costs.

[0034] like Figure 1The diagram shown is a circuit schematic of one embodiment of the motor encoder drive circuit of this application. In this embodiment, the motor encoder drive circuit includes an optocoupler and a drive current adjustment circuit disposed between the input side (drive side) and the output side of the optocoupler. The drive current adjustment circuit is used to adjust the drive current on the input side according to the output voltage of the output side. The drive current adjustment circuit includes a feedback detection circuit (e.g., an operational amplifier), a main control IC, and a constant current source I1 sequentially connected between the output side and the input side of the optocoupler.

[0035] Continue to refer to, for example Figure 1 The optocoupler includes an LED element and a photosensitive element S. The input terminal of the LED element is configured as the first connection terminal 1 on the input side of the optocoupler, and the output terminal of the LED element is configured as the second connection terminal 2 on the input side of the optocoupler. The input terminal of the photosensitive element S is configured as the third connection terminal 3 on the output side of the optocoupler, and the output terminal of the photosensitive element S is configured as the fourth connection terminal 4 on the output side of the optocoupler.

[0036] In this configuration, the first connection terminal 1 is connected to the first voltage V, the constant current source I1 is connected between the second connection terminal 2 and the power supply ground, and the control terminal of the main control IC is connected to the constant current source I1 to adjust the driving current I of the constant current source I1 to drive the LED element to emit light; the third connection terminal 3 is connected to the second voltage Vref through a resistor R (the third resistor), the fourth connection terminal 4 is connected to the power supply ground, the third connection terminal 3 is connected to the positive input terminal of the operational amplifier, and the output terminal of the operational amplifier is connected to the input terminal of the main control IC and the negative input terminal of the operational amplifier. The operational amplifier is used to collect the output voltage of the optocoupler and feed it back to the main control IC, thereby determining the luminous intensity of the LED element.

[0037] In this embodiment, the main control IC controls the current on the drive side of the optocoupler to control the luminous intensity of the LED element. The output voltage of the optocoupler is detected on the output side. The output voltage of the optocoupler and the luminous intensity of the LED element are directly correlated; knowing the change in output voltage indicates the change in LED element luminous intensity. The main control IC used is NXP's S32K341, but this application is not limited to this; any MCU can be used as the main control IC.

[0038] When the temperature changes, even if the driving current remains constant, the light intensity of the LED element will change, which will cause the output voltage to change. The main control IC monitors this change through a voltage feedback detection circuit, and then adjusts the driving current I on the driving side to adjust the output voltage to a stable value, thereby achieving temperature compensation.

[0039] For example, the output voltage Vout = Vref - Iout * R. When temperature changes cause the luminous intensity of the optocoupler to increase, Iout increases and Vout decreases. The main control IC detects the decrease in Vout and adjusts the constant current source to reduce the current. This weakens the luminous intensity of the optocoupler, causing Iout to decrease and Vout to increase. Adjustment stops when Vout reaches its initial value. Conversely, when temperature causes the luminous intensity of the optocoupler to decrease, the main control IC adjusts in the opposite direction.

[0040] The optocoupler can be the VCNT-2025x01, but this application is not limited to it; other types or models of optocouplers can also be used. The output-side resistor R converts the optocoupler's output current into an output voltage. The value of resistor R depends on the choice of optocoupler. For example, with Vref at 5V, if the optocoupler is the VCNT-2025X01, the resistor can be 2K~5K. The operational amplifier can be the LM358, but this application is not limited to it; other operational amplifiers of the same type as the LM358 can also be used. The first voltage V on the drive side is generally 5V, and the second voltage Vref on the output side is generally 5V.

[0041] like Figure 2 The diagram shown is a circuit schematic of another embodiment of the motor encoder drive circuit of this application. This embodiment is similar to... Figure 1 The embodiments shown are basically the same, the only difference being that the constant current source I2 in this application is connected between the first connection terminal 1 of the optocoupler and the first voltage V. Other similarities can be found in the foregoing embodiments, and will not be repeated here.

[0042] like Figure 3 The diagram shown is a circuit schematic of another embodiment of the motor encoder drive circuit of this application. This embodiment is similar to... Figure 2 The illustrated embodiments are essentially the same, with the only difference being that a resistor R1 (first resistor) is connected between the output terminal and the negative input terminal of the operational amplifier, and the negative input terminal of the operational amplifier is connected to the power supply ground through a resistor R2 (second resistor). The values ​​of resistors R1 and R2 are between 1K and 50K. Through the cooperation of resistors R1 and R2 and the operational amplifier, the output voltage is amplified, facilitating voltage acquisition by the main control IC. Other similarities can be found in the aforementioned embodiments and will not be repeated here.

[0043] like Figure 4 The diagram shown is a circuit schematic of another embodiment of the optocoupler in this application. Figure 4In the illustrated embodiment, the connection terminals marked 1 to 4 correspond to the first to fourth connection terminals in the aforementioned embodiments of this application, respectively. The connection terminal marked 5 can be connected to the reference voltage Vref in the aforementioned embodiments via a resistor or to another external power supply. The connection terminal marked 5 is used to adjust the sensitivity of the optocoupler. Figure 4 The optocoupler shown replaces the optocoupler in the motor encoder drive circuit of the aforementioned embodiments of this application.

[0044] like Figure 5 The diagram shown is a circuit schematic of another embodiment of the optocoupler in this application. Figure 5 In the illustrated embodiment, the connection terminals marked 1 to 4 correspond to the first to fourth connection terminals in the aforementioned embodiments of this application, respectively. The connection terminal marked 5 can be connected to the reference voltage Vref in the aforementioned embodiments via a resistor or to another external power supply. The connection terminal marked 5 is used to adjust the sensitivity of the optocoupler. Figure 5 The optocoupler shown replaces the optocoupler in the motor encoder drive circuit of the aforementioned embodiments of this application.

[0045] like Figure 6 The diagram shown is a circuit schematic of another embodiment of the optocoupler in this application. Figure 6 In the illustrated embodiment, the connection terminals marked with serial numbers 1 to 4 correspond to the first to fourth connection terminals in the aforementioned embodiments of this application, respectively, and can be used to... Figure 6 The optocoupler shown replaces the optocoupler in the motor encoder drive circuit of the aforementioned embodiments of this application.

[0046] like Figure 7 The diagram shown is a circuit schematic of another embodiment of the optocoupler in this application. Figure 7 In the illustrated embodiment, the connection terminals marked 1 to 4 correspond to the first to fourth connection terminals in the aforementioned embodiments of this application, respectively. The connection terminal marked 5 can be connected to the reference voltage Vref in the aforementioned embodiments via a resistor or to another external power supply. The connection terminal marked 5 is used to adjust the sensitivity of the optocoupler. Figure 7 The optocoupler shown replaces the optocoupler in the motor encoder drive circuit of the aforementioned embodiments of this application.

[0047] In some embodiments, this application also provides a motor that includes the motor encoder drive circuit described in any embodiment of this application. It should be noted that the motor in the embodiments of this application does not limit the structure other than the motor encoder drive circuit.

[0048] In some embodiments, this application also provides a sensor that includes the motor described in any embodiment of this application. It should be noted that the sensor in this application does not limit the use of structures other than a motor.

[0049] In some embodiments, this application also provides a mobile platform that includes the sensor described in any embodiment of this application. It should be noted that the mobile platform in this application does not limit the use of structures other than sensors.

[0050] This application provides a motor encoder drive circuit that adjusts the drive current on the input side based on the output voltage of the output side by incorporating a drive current regulation circuit between the input and output sides of an optocoupler. Motors, sensors, or mobile platforms using this circuit only require appropriate configuration of the drive current regulation circuit to adjust the drive current on the input side according to the output voltage. This allows the circuit to sense the impact of temperature changes on the optocoupler output by detecting variations in the output voltage, and subsequently overcome the influence of temperature changes on the position detection accuracy of the optocoupler by controlling the drive current of the optocoupler.

[0051] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0052] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0053] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0054] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0055] The foregoing disclosure provides many different implementations or examples for carrying out different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described above. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various implementations and / or arrangements discussed.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. An electric motor encoder drive circuit, characterized by, include: An optocoupler includes an input side and an output side; A drive current adjustment circuit is connected between the input side and the output side of the optocoupler, and is used to adjust the drive current on the input side according to the output voltage on the output side; The drive current regulation circuit includes: A constant current source and a controller are sequentially connected between the input side and the output side; the controller is used to control the drive current of the constant current source according to the output voltage of the output side. A feedback voltage detection circuit is disposed between the controller and the output side of the optocoupler, the feedback voltage detection circuit including an operational amplifier; The input side of the optocoupler includes a first connection terminal and a second connection terminal; the output side of the optocoupler includes a third connection terminal and a fourth connection terminal; wherein... The first connection terminal is connected to a first voltage, and the constant current source is connected between the second connection terminal and the power supply ground; or, the constant current source is connected between the first voltage and the first connection terminal, and the second connection terminal is connected to the power supply ground; the control terminal of the controller is connected to the constant current source to adjust the drive current of the constant current source. The third connection terminal is connected to the second voltage, the fourth connection terminal is connected to the power supply ground, and the third connection terminal is connected to the positive input terminal of the operational amplifier; the output terminal of the operational amplifier is connected to the input terminal of the controller and the negative input terminal of the operational amplifier, or the output terminal of the operational amplifier is connected to the negative input terminal of the operational amplifier through a first resistor, and the negative input terminal of the operational amplifier is connected to the power supply ground through a second resistor.

2. The circuit according to claim 1, characterized in that, A third resistor is provided between the second voltage and the third connection terminal.

3. The circuit according to claim 2, characterized in that, The resistance value of the third resistor is in the range of 2K~5K.

4. The circuit according to any one of claims 1-3, characterized in that, The input side of the optocoupler includes an LED element, the input terminal of which is configured as the first connection terminal, and the output terminal of which is configured as the second connection terminal.

5. The circuit according to claim 4, characterized in that, The output side of the optocoupler includes a photosensitive element, the input end of which is configured as a third connection end, and the output end of which is configured as a fourth connection end.

6. An electric motor, characterized in that, Includes the motor encoder drive circuit as described in any one of claims 1-5.

7. A sensor, characterized in that, Includes the motor as described in claim 6.

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