Steering engine limiting circuit

Abstract

The invention relates to the technical field of steering engines, and discloses a steering engine limiting circuit which comprises a reverse comparison module connected with a potentiometer and used for receiving feedback voltage of the potentiometer and outputting a lower limit comparison result after comparing the feedback voltage with lower limit reference voltage, and the feedback voltage is voltage corresponding to the current position; the forward comparison module is connected with the potentiometer and is used for receiving the feedback voltage, comparing the feedback voltage with an upper limit reference voltage and outputting an upper limit comparison result; the detection module is connected with the lower limit comparison module and the upper limit comparison module and used for receiving the lower limit comparison result and the upper limit comparison result, obtaining a control signal based on the lower limit comparison result and the upper limit comparison result and outputting the control signal to the steering engine power supply end to control power supply of the steering engine so as to limit the steering engine. The problem that a high-precision mechanical limiting device is high in cost is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of steering gears, and in particular to a steering gear limiting circuit. Background Art

[0002] A servo is a device that can control parameters such as angle, speed, and position. It is usually composed of a motor, a reducer, and a control circuit. The purpose of the servo's angle limit is to prevent the servo from over-rotating or exceeding the design limit, thereby protecting the safety and reliability of the system. The design of the servo limit helps prevent the mechanical system from operating when the rudder angle is too large or too small, which not only avoids adverse effects on the control of the system equipment, but also protects the servo from overload and damage.

[0003] The existing steering gear angle limit is to set a mechanical limit device. A mechanical limit device similar to a limit lever is designed in the steering gear to limit the steering angle range of the steering gear. When the steering gear reaches the limit position, the mechanical limit device will prevent further steering angle movement.

[0004] However, the limit accuracy of the mechanical limit device is not only affected by the machining accuracy of the mechanical limit device, but also by the installation accuracy of the servo output end. The production and processing center can generally ensure that the machining accuracy is within ±3′ (±0.05°), but the mechanical zero position accuracy of the servo output end is generally required to be ±0.2°, resulting in low accuracy of the mechanical limit device, and therefore high cost caused by precision processing. Summary of the invention

[0005] In view of this, the present invention provides a steering gear limit circuit to solve the problem of high cost of high-precision mechanical limit devices.

[0006] In a first aspect, the present invention provides a steering gear limit circuit, the circuit comprising:

[0007] A reverse comparison module is connected to the potentiometer, and is used to receive a feedback voltage from the potentiometer, and compare the feedback voltage with a lower limit reference voltage, and then output a lower limit comparison result;

[0008] A positive comparison module is connected to the potentiometer and is used to receive a feedback voltage, compare the feedback voltage with an upper limit reference voltage, and output an upper limit comparison result, wherein the feedback voltage is a voltage corresponding to the current position;

[0009] The detection module is connected to the lower limit comparison module and the upper limit comparison module respectively, and is used to receive the lower limit comparison result and the upper limit comparison result, and obtain a control signal based on the lower limit comparison result and the upper limit comparison result, and output the control signal to the servo power supply end to control the servo power supply so as to limit the servo.

[0010] The servo limit circuit provided by the present invention obtains the feedback voltage signal of the potentiometer and controls the power supply of the servo motor according to the comparison result of the feedback voltage signal. There is no need to set a high-precision mechanical limit device and an angle sensor, thereby greatly reducing the cost.

[0011] In an optional implementation, the reverse comparison module includes:

[0012] A lower limit reference unit, the lower limit reference unit is connected to the power supply terminal and is used to output a lower limit reference voltage;

[0013] The reverse hysteresis comparison unit is connected to the lower limit reference unit, the potentiometer and the detection module respectively, and is used to receive the lower limit reference voltage and the feedback voltage, perform hysteresis comparison on the lower limit reference voltage and the feedback voltage, and output the lower limit comparison result.

[0014] In an optional implementation, the reverse hysteresis comparison unit includes:

[0015] a first resistor, wherein a first end of the first resistor is connected to the potentiometer;

[0016] A first comparator, wherein a first input terminal of the first comparator is connected to the lower limit reference unit, a second input terminal of the first comparator is connected to the second end of the first resistor, an output terminal of the first comparator is connected to the first input terminal of the detection module, a positive power supply terminal of the first comparator is connected to the power supply terminal, and a negative power supply terminal of the first comparator is grounded;

[0017] A second resistor, wherein a first end of the second resistor is connected to the second input end of the first comparator, and a second end of the second resistor is connected to the output end of the first comparator.

[0018] In an optional implementation, the reverse hysteresis comparison unit further includes:

[0019] A first capacitor, a first end of the first capacitor is connected to the potentiometer, and a second end of the first capacitor is grounded;

[0020] A second capacitor, wherein a first end of the second capacitor is connected to the positive power supply end of the first comparator, and a second end of the second capacitor is grounded;

[0021] A third capacitor, wherein a first end of the third capacitor is connected to the negative power supply end of the first comparator, and a second end of the third capacitor is grounded.

[0022] In an optional implementation, the lower limit reference unit includes:

[0023] A third resistor, a first end of the third resistor is connected to the power supply end;

[0024] a fourth resistor, wherein a first end of the fourth resistor is connected to a second end of the third resistor, and a second end of the fourth resistor is grounded;

[0025] A fourth capacitor, wherein a first end of the fourth capacitor is connected to the second end of the third resistor, and a second end of the fourth capacitor is grounded.

[0026] In an optional implementation, the forward comparison module includes:

[0027] An upper limit reference unit, the upper limit reference unit is connected to the power supply terminal and is used to output an upper limit reference voltage;

[0028] The positive hysteresis comparison unit is connected to the upper limit reference unit, the potentiometer and the detection module respectively, and is used to receive the upper limit reference voltage and the feedback voltage, perform hysteresis comparison on the upper limit reference voltage and the feedback voltage, and output the upper limit comparison result.

[0029] In an optional implementation, the forward hysteresis comparison unit includes:

[0030] a fifth resistor, wherein a first end of the fifth resistor is connected to the upper limit reference unit;

[0031] A second comparator, wherein a first input terminal of the second comparator is connected to a second terminal of the fifth resistor, a second input terminal of the second comparator is connected to a potentiometer, an output terminal of the second comparator is connected to a second input terminal of the detection module, a positive power supply terminal of the second comparator is connected to a power supply terminal, and a negative power supply terminal of the second comparator is grounded;

[0032] A sixth resistor, wherein a first end of the sixth resistor is connected to the first input end of the second comparator, and a second end of the sixth resistor is connected to the output end of the second comparator.

[0033] In an optional implementation, the upper limit reference unit includes:

[0034] a seventh resistor, wherein a first end of the seventh resistor is connected to the power supply end;

[0035] an eighth resistor, wherein a first end of the eighth resistor is connected to a second end of the seventh resistor, and a second end of the eighth resistor is grounded;

[0036] A fifth capacitor, wherein a first end of the fifth capacitor is connected to a second end of the seventh resistor, and a second end of the fifth capacitor is grounded.

[0037] In an optional embodiment, the detection module includes:

[0038] An AND gate device, wherein the first input end of the AND gate device is connected to the reverse comparison module, the second input end of the AND gate device is connected to the forward comparison module, the output end of the AND gate device is connected to the servo power supply end, and is used to receive a lower limit comparison result and an upper limit comparison result, the output end of the AND gate device is connected to the servo power supply end, and the AND gate device outputs a control signal based on the lower limit comparison result and the upper limit comparison result. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0040] Figure 1 is a structural diagram of a steering gear limit circuit according to an embodiment of the present invention;

[0041] Figure 2 is a schematic diagram of lower limit control of a steering gear limit circuit according to an embodiment of the present invention;

[0042] Figure 3 is a schematic diagram of upper limit control of a steering gear limit circuit according to an embodiment of the present invention;

[0043] Figure 4 1 is a schematic diagram of a steering gear control of a steering gear limiting circuit according to an embodiment of the present invention. DETAILED DESCRIPTION

[0044] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0046] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, it can also be the internal connection of two components, it can be a wireless connection, or it can be a wired connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0048] In the related art, the main methods of limiting the steering gear angle are mechanical limiting devices and sensor detection. The mechanical limiting device limits the steering gear's rudder angle range through a limiting lever, and the sensor detection detects the steering gear's rudder angle by installing a sensor and sends a signal when the preset rudder angle limit is reached. When it is detected that the rudder angle exceeds the design limit, the control system can take corresponding measures, such as sounding an alarm, automatically stopping the steering gear movement, etc. However, sensor detection requires the arrangement of angle sensors and the design of detection circuits. The detection accuracy is limited by the accuracy of the sensor, resulting in complexity and high cost, and does not meet the economic requirements. In addition, the sensor detection angle can only achieve a single-point steering gear limit, and its sensitivity is very high, but its anti-interference performance is poor. Slight fluctuations in the detection signal near the steering gear limit position will cause frequent jumps in the steering gear output signal.

[0049] In this embodiment, a steering gear limit circuit is provided, such as Figure 1 , Figure 1 : is a structural diagram of a steering gear limiting circuit according to an embodiment of the present invention, the circuit comprises:

[0050] A reverse comparison module 10, which is connected to the potentiometer, is used to receive a feedback voltage VF of the potentiometer, and compare the feedback voltage VF with a lower limit reference voltage Vref1, and then output a lower limit comparison result V12 EN1, wherein the feedback voltage VF is a voltage corresponding to the current position;

[0051] A positive comparison module 20, the positive comparison module 20 is connected to the potentiometer, and is used to receive the feedback voltage VF, and compare the feedback voltage VF with the upper limit reference voltage Vref2, and then output an upper limit comparison result V12 EN2;

[0052] The detection module 30 is connected to the lower limit comparison module 10 and the upper limit comparison module 20 respectively, and is used to receive the lower limit comparison result and the upper limit comparison result, and obtain the control signal V12EN based on the lower limit comparison result and the upper limit comparison result, and output the control signal to the servo power supply end to control the power supply of the servo, so as to limit the servo.

[0053] The lower limit reference voltage Vref1 can be the voltage of the servo potentiometer when the target minimum limit angle is set, and the upper limit reference voltage Vref2 can be the voltage of the servo potentiometer when the target maximum limit angle is set. The lower limit comparison result output by the reverse comparison module 10 to the detection module 30 is V12 EN1, and the upper limit comparison result output by the forward comparison module 20 to the detection module 30 is V12 EN2. After performing a logic operation based on the lower limit comparison result V12 EN1 and the upper limit comparison result V12 EN2, the detection module 30 outputs a control signal V12 EN for driving the motor power supply of the servo, and the control signal includes power on and power off. That is, when the lower limit comparison result V12 EN1 and the upper limit comparison result V12 EN2 of the detection feedback voltage VF meet the requirements, that is, when they are within the preset range, the motor power supply is allowed, and when they are not within the preset range, the motor power supply is disconnected. Among them, when the lower limit comparison result V12EN1 received by the detection module 30 is a high level, the feedback voltage VF meets the lower limit requirement, and when the upper limit comparison result V12EN2 received by the detection module 30 is a high level, the feedback voltage VF meets the upper limit requirement. Only when the feedback voltage VF meets both the lower limit requirement and the upper limit requirement, a high level is output to the servo power supply end to control the servo power supply end to power on. Thus, by obtaining the feedback voltage signal of the potentiometer and controlling the power supply of the servo motor according to the comparison result of the feedback voltage signal, there is no need to set a high-precision mechanical limit device and an angle sensor, thereby greatly reducing the cost.

[0054] For example, the full range of the potentiometer is 110° and the power supply voltage is 5V, and the center point of the potentiometer is set to 0°, then the center point voltage is 2.5V, and the feedback voltage VF is the voltage fed back from the current position. Specifically, the lower limit reference voltage Vref1 can be set to 1.35V, and the upper limit reference voltage Vref2 can be set to 3.65V. Specifically, the reverse comparison module 10 outputs the lower limit comparison result V12EN1 as a high level when it detects that the feedback voltage VF is greater than 1.35V, and the forward comparison module 20 outputs the upper limit comparison result V12EN2 as a high level when it detects that the feedback voltage VF is less than 3.65V. After receiving the two high levels, the detection module 30 outputs a high level to the servo power supply terminal to control the servo power supply terminal to power on.

[0055] In some optional embodiments, such as Figure 1 As shown, the reverse comparison module 10 includes:

[0056] A lower limit reference unit 11, the lower limit reference unit 11 is connected to the power supply terminal VCC and is used to output a lower limit reference voltage Vref1;

[0057] The reverse hysteresis comparison unit 12 is connected to the lower limit reference unit 11, the potentiometer and the detection module 30 respectively, and is used to receive the lower limit reference voltage Vref1 and the feedback voltage VF, perform hysteresis comparison on the lower limit reference voltage Vref1 and the feedback voltage VF, and output the lower limit comparison result V12EN1.

[0058] The reverse hysteresis comparison unit 12 is used to perform hysteresis comparison, that is, instead of directly comparing the lower limit reference voltage Vref1 with the feedback voltage VF, the combination of the lower limit comparison result V12 EN1 and the feedback voltage VF is compared with the lower limit reference voltage Vref1. Therefore, compared with only comparing the feedback voltage VF with the lower limit reference voltage Vref1, the lower limit comparison result V12 EN1 at the previous moment can be used to affect the lower limit comparison result V12 EN1 at the current moment. Furthermore, on the basis of setting the lower limit power supply threshold of the feedback voltage VF, the lower limit jitter threshold of the servo after power-on is also set, which greatly improves the reliability of the servo operation.

[0059] In some optional embodiments, such as Figure 1 As shown, the reverse hysteresis comparison unit 12 includes:

[0060] A first resistor R1, a first end of the first resistor R1 is connected to the potentiometer;

[0061] A first comparator A1, wherein a first input terminal of the first comparator A1 is connected to the lower limit reference unit 11, a second input terminal of the first comparator A1 is connected to the second terminal of the first resistor R1, an output terminal of the first comparator A1 is connected to the first input terminal of the detection module 30, a positive power supply terminal of the first comparator A1 is connected to the power supply terminal VCC, and a negative power supply terminal of the first comparator A1 is grounded;

[0062] A second resistor R2, wherein a first end of the second resistor R2 is connected to the second input end of the first comparator A1, and a second end of the second resistor R2 is connected to the output end of the first comparator A1.

[0063] It should be noted that the reverse hysteresis comparison unit 12 does not directly compare the feedback voltage VF with the lower limit reference voltage Vref1, because the first comparator A1 uses a rail-to-rail operational amplifier. The reverse input lower limit reference voltage Vref1 of the first comparator A1 and the positive input feedback voltage VF of the first comparator A1 constitute a hysteresis comparator circuit in which the feedback voltage VF is input from the positive input of the operational amplifier. According to the voltage superposition theorem,

[0064]

[0065] Thus, we can obtain

[0066]

[0067] The first comparator A1 outputs a high level and a low level, the high level is 5V, the low level is 0V, when the output terminal Vout1 of the first comparator takes the minimum value 0V, the threshold of the feedback voltage VF is 1.38V; when the output terminal Vout1 of the first comparator takes the maximum value 5V, the threshold of the feedback voltage VF is 1.28V, where the threshold width is 0.1V. At this time, the reference Figure 2 , Figure 2 is the output transfer characteristic curve of the output terminal Vout1 of the first comparator. Since the hysteresis circuit actually compares the VP1 point and the lower limit reference voltage Vref1, the voltage of the output terminal Vout1 of the first comparator has an impact on the comparison result. When the feedback voltage VF drops from high voltage to 1.28V, the output terminal Vout1 of the first comparator changes from high level to low level. When the feedback voltage VF increases from low voltage to 1.38V, the output terminal Vout1 of the first comparator changes from low level to high level. It can be understood that the lower limit threshold of the servo motor power-on is 1.38V, that is, when the feedback voltage VF is greater than 1.38V, the lower limit comparison result V12 EN1 outputs a high level, and the lower limit threshold of the jitter of the servo motor after power-on is 1.28V, that is, when the feedback voltage VF drops to 1.28V, it outputs a low level. In other words, when the feedback voltage VF fluctuates slightly near the servo limit position, the motor will not be powered on again, which greatly improves the stability of the jitter when the servo rotates in the opposite direction.

[0068] In some optional embodiments, such as Figure 1 As shown, the reverse hysteresis comparison unit 12 also includes:

[0069] A first capacitor C1, a first end of the first capacitor C1 is connected to the potentiometer, and a second end of the first capacitor C1 is grounded;

[0070] A second capacitor C2, wherein a first end of the second capacitor C2 is connected to the positive power supply end of the first comparator A1, and a second end of the second capacitor C2 is grounded;

[0071] A third capacitor C3, a first end of the third capacitor C3 is connected to the negative power supply end of the first comparator A1, and a second end of the third capacitor C3 is grounded.

[0072] The first capacitor C1 plays a role of filtering the feedback voltage VF, and the second capacitor C2 and the third capacitor C3 play a role of filtering.

[0073] In some optional embodiments, such as Figure 1As shown, the lower limit reference unit 11 includes:

[0074] A third resistor R3, a first end of the third resistor R3 is connected to the power supply end VCC;

[0075] a fourth resistor R4, wherein a first end of the fourth resistor R4 is connected to a second end of the third resistor R3, and a second end of the fourth resistor R4 is grounded;

[0076] A fourth capacitor C4, a first end of the fourth capacitor C4 is connected to the second end of the third resistor R3, and a second end of the fourth capacitor C4 is grounded.

[0077] The voltage of the power supply terminal VCC is 5V, and the voltage division of the third resistor R3 and the fourth resistor R4 provides a lower limit reference voltage Vref1 of 1.35V to the inverting input terminal of the first comparator A1. The fourth capacitor C4 plays a role in filtering the lower limit reference voltage Vref1.

[0078] In some optional embodiments, such as Figure 1 As shown, the forward comparison module 20 includes:

[0079] An upper limit reference unit 21, the upper limit reference unit 21 is connected to the power supply terminal VCC and is used to output an upper limit reference voltage Vref2;

[0080] The positive hysteresis comparison unit 22 is connected to the upper limit reference unit 21, the potentiometer and the detection module 30 respectively, and is used to receive the upper limit reference voltage Vref2 and the feedback voltage VF, and perform hysteresis comparison on the upper limit reference voltage Vref2 and the feedback voltage VF, and output the upper limit comparison result V12EN2.

[0081] The positive hysteresis comparison unit 22 is used to perform hysteresis comparison, that is, instead of directly comparing the upper limit reference voltage Vref2 with the feedback voltage VF, the combination of the upper limit comparison result V12 EN2 and the feedback voltage VF is compared with the upper limit reference voltage Vref2. Therefore, compared with only comparing the feedback voltage VF with the upper limit reference voltage Vref2, the upper limit comparison result V12 EN2 at the previous moment can be used to affect the upper limit comparison result V12 EN2 at the current moment. Furthermore, on the basis of setting the upper limit power supply threshold of the feedback voltage VF, the upper limit jitter threshold of the servo after power-on is also set, which greatly improves the reliability of the servo operation.

[0082] In some optional embodiments, such as Figure 1 As shown, the forward hysteresis comparison unit 22 includes:

[0083] a fifth resistor R5, wherein a first end of the fifth resistor R5 is connected to the upper limit reference unit 21;

[0084] A second comparator A2, wherein a first input terminal of the second comparator A2 is connected to a second terminal of the fifth resistor R5, a second input terminal of the second comparator A2 is connected to a potentiometer, an output terminal of the second comparator A2 is connected to a second input terminal of the detection module 30, a positive power supply terminal of the second comparator A2 is connected to a power supply terminal VCC, and a negative power supply terminal of the second comparator A2 is grounded;

[0085] A sixth resistor R6, a first end of the sixth resistor R6 is connected to the first input end of the second comparator A2, and a second end of the sixth resistor R6 is connected to the output end of the second comparator A2.

[0086] It should be noted that the positive hysteresis comparison unit 22 does not directly compare the feedback voltage VF with the upper limit reference voltage Vref2, because the second comparator A2 uses a rail-to-rail operational amplifier. The upper limit reference voltage Vref2 is input to the positive input of the second comparator A2, and the feedback voltage VF is input to the reverse input of the second comparator A2, forming a hysteresis comparator circuit in which the feedback voltage VF is input from the reverse input of the operational amplifier. According to the voltage superposition theorem, it is obtained that:

[0087]

[0088] The second comparator A1 outputs high level and low level, the high level is 5V, the low level is 0V, when the output terminal Vout2 of the second comparator takes the minimum value 0V, the threshold of the feedback voltage VF is 3.58V; when the output terminal Vout2 of the second comparator takes the maximum value 5V, the threshold of the feedback voltage VF is 3.68V, where the threshold width is 0.1V. At this time, the reference Figure 3 , Figure 3 is the output transfer characteristic curve of the output terminal Vout2 of the second comparator. Since the hysteresis circuit actually compares the VP2 point and the upper limit reference voltage Vref2, the voltage of the output terminal Vout2 of the second comparator has an impact on the comparison result. When the feedback voltage VF increases from low voltage to 3.68V, the output terminal Vout2 of the second comparator changes from high level to low level. When the feedback voltage VF drops from high voltage to 3.58V, the output terminal Vout2 of the second comparator changes from low level to high level. It can be understood that the lower limit threshold of the servo motor power-on is 3.58V, that is, when the feedback voltage VF is less than 3.58V, the upper limit comparison result V12 EN2 outputs a high level, and the upper limit threshold of the jitter of the servo motor after power-on is 3.68V, that is, when the feedback voltage VF increases to 3.68V, it outputs a low level. In other words, when the feedback voltage VF fluctuates slightly near the servo limit position, the motor will not be powered on again, which greatly improves the stability of the jitter during the forward rotation of the servo.

[0089] In some optional embodiments, such as Figure 1As shown, the upper limit reference unit includes:

[0090] a seventh resistor R7, wherein a first end of the seventh resistor R7 is connected to the power supply end VCC;

[0091] an eighth resistor R8, wherein a first end of the eighth resistor R8 is connected to a second end of the seventh resistor R7, and a second end of the eighth resistor R8 is grounded;

[0092] A fifth capacitor C5, a first end of the fifth capacitor C5 is connected to the second end of the seventh resistor R7, and a second end of the fifth capacitor C5 is grounded.

[0093] The voltage of the power supply terminal VCC is 5V, and the voltage division of the seventh resistor R7 and the eighth resistor R8 provides the upper limit reference voltage Vref2 of 3.65V to the inverting input terminal of the second comparator A2. The fifth capacitor C5 plays a role in filtering the upper limit reference voltage Vref2.

[0094] In some optional embodiments, such as Figure 1 As shown, the detection module 30 includes:

[0095] AND gate device U1, a first input end of the AND gate device U1 is connected to the reverse comparison module 10, a second input end of the AND gate device U1 is connected to the forward comparison module 20, an output end of the AND gate device U1 is connected to the servo power supply end, and is used to receive the lower limit comparison result V12 EN1 and the upper limit comparison result V12 EN2. The AND gate device U1 outputs a control signal V12 EN based on the lower limit comparison result V12 EN1 and the upper limit comparison result V12 EN2.

[0096] The AND gate device U1 outputs a high level only when all inputs are high at the same time, otherwise it is a low level. Therefore, when the upper limit comparison result V12 EN2 and the lower limit comparison result V12 EN1 are both high at the same time, the output is a high level, thereby powering on the power supply end of the servo motor.

[0097] In some optional embodiments, such as Figure 1 As shown, the detection module 30 also includes:

[0098] A ninth resistor R9, a first end of the ninth resistor R9 is connected to the output end of the AND gate device U1, and a second end of the ninth resistor R9 is connected to the power supply end of the steering gear.

[0099] The ninth resistor R9 plays the role of voltage regulation and protection, thereby outputting the control signal V12 EN to the steering gear power supply terminal.

[0100] refer to Figure 4, the servo motor is powered on when the control signal V12 EN outputs a high level, and the servo motor is powered off when the output is a low level. When the control signal V12 EN of the servo potentiometer is in the high level working area, the servo is limited when the servo rotates in the reverse direction to -26.84°. At this time, the detection feedback voltage VF will not cause the motor to be powered on again if it fluctuates slightly near the servo limit position, and the hysteresis range is 1.1°, until it is reduced to -25.74° and powered on again; when the control signal V12 EN of the servo potentiometer is in the high level working area, the servo is limited when the servo rotates in the positive direction to 24.86°. At this time, the detection feedback voltage VF will not cause the motor to be powered on again if it fluctuates slightly near the servo limit position, and the hysteresis range is 1.1°, until it is reduced to 23.76° and powered on again.

[0101] That is to say, when the feedback voltage VF is between 1.38V and 3.58V, that is, when the angle is between -25.74° and 23.76°, the detection module 30 outputs a high level to control the power supply end of the servo to power on, and after the servo is powered on, the jitter range is between 1.28V and 3.68V, that is, the angle is between -26.84° and 24.86°. Figure 4 Area a in the figure indicates the lower limit jitter tolerance area of ​​the servo after power-on, and area b indicates the upper limit jitter tolerance area of ​​the servo after power-on. There is a 0.1V tolerance value above and below, thereby avoiding output jumps caused by jitter of the feedback voltage VF.

[0102] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the scope of protection of the invention.

Claims

1. A steering gear limit circuit, characterized in that: The circuit comprises: A reverse comparison module, the reverse comparison module is connected to the potentiometer, and is used to receive a feedback voltage from the potentiometer, and compare the feedback voltage with a lower limit reference voltage, and then output a lower limit comparison result, wherein the feedback voltage is a voltage corresponding to the current position; A forward comparison module, the forward comparison module is connected to the potentiometer, and is used to receive the feedback voltage, and compare the feedback voltage with an upper limit reference voltage, and then output an upper limit comparison result; A detection module, wherein the detection module is connected to the lower limit comparison module and the upper limit comparison module respectively, and is used to receive the lower limit comparison result and the upper limit comparison result, and obtain a control signal based on the lower limit comparison result and the upper limit comparison result, and output the control signal to the servo power supply end to control the power supply of the servo, so as to limit the servo.

2. The circuit according to claim 1, characterized in that The reverse comparison module comprises: A lower limit reference unit, the lower limit reference unit is connected to the power supply terminal and is used to output a lower limit reference voltage; A reverse hysteresis comparison unit, wherein the reverse hysteresis comparison unit is respectively connected to the lower limit reference unit, the potentiometer and the detection module, and is used to receive the lower limit reference voltage and the feedback voltage, perform hysteresis comparison on the lower limit reference voltage and the feedback voltage, and output a lower limit comparison result.

3. The circuit according to claim 2, characterized in that The reverse hysteresis comparison unit comprises: a first resistor, wherein a first end of the first resistor is connected to the potentiometer; A first comparator, wherein a first input terminal of the first comparator is connected to the lower limit reference unit, a second input terminal of the first comparator is connected to the second end of the first resistor, an output terminal of the first comparator is connected to the first input terminal of the detection module, a positive power supply terminal of the first comparator is connected to a power supply terminal, and a negative power supply terminal of the first comparator is grounded; A second resistor, wherein a first end of the second resistor is connected to the second input end of the first comparator, and a second end of the second resistor is connected to the output end of the first comparator.

4. The circuit according to claim 3, characterized in that The reverse hysteresis comparison unit also includes: A first capacitor, wherein a first end of the first capacitor is connected to the potentiometer, and a second end of the first capacitor is grounded; a second capacitor, wherein a first end of the second capacitor is connected to the positive power supply end of the first comparator, and a second end of the second capacitor is grounded; A third capacitor, wherein a first end of the third capacitor is connected to the negative power supply end of the first comparator, and a second end of the third capacitor is grounded.

5. The circuit according to claim 4, characterized in that The lower limit reference unit comprises: a third resistor, a first end of the third resistor being connected to the power supply end; a fourth resistor, wherein a first end of the fourth resistor is connected to a second end of the third resistor, and a second end of the fourth resistor is grounded; A fourth capacitor, wherein a first end of the fourth capacitor is connected to the second end of the third resistor, and a second end of the fourth capacitor is grounded.

6. The circuit according to claim 1, characterized in that The forward comparison module comprises: An upper limit reference unit, the upper limit reference unit is connected to the power supply terminal and is used to output an upper limit reference voltage; A positive hysteresis comparison unit is connected to the upper limit reference unit, the potentiometer and the detection module respectively, and is used to receive the upper limit reference voltage and the feedback voltage, perform hysteresis comparison on the upper limit reference voltage and the feedback voltage, and output an upper limit comparison result.

7. The circuit according to claim 6, characterized in that The forward hysteresis comparison unit comprises: a fifth resistor, a first end of the fifth resistor being connected to the upper limit reference unit; A second comparator, wherein a first input terminal of the second comparator is connected to the second terminal of the fifth resistor, a second input terminal of the second comparator is connected to the potentiometer, an output terminal of the second comparator is connected to the second input terminal of the detection module, a positive power supply terminal of the second comparator is connected to the power supply terminal, and a negative power supply terminal of the second comparator is grounded; a sixth resistor, wherein a first end of the sixth resistor is connected to the first input end of the second comparator, and a second end of the sixth resistor is connected to the output end of the second comparator.

8. The circuit according to claim 7, characterized in that The upper limit reference unit comprises: a seventh resistor, wherein a first end of the seventh resistor is connected to the power supply end; an eighth resistor, a first end of the eighth resistor being connected to the second end of the seventh resistor, and a second end of the eighth resistor being grounded; A fifth capacitor, wherein a first end of the fifth capacitor is connected to a second end of the seventh resistor, and a second end of the fifth capacitor is grounded.

9. The circuit according to claim 1, characterized in that The detection module comprises: An AND gate device, wherein the first input end of the AND gate device is connected to the reverse comparison module, the second input end of the AND gate device is connected to the forward comparison module, and the output end of the AND gate device is connected to the servo power supply end, and is used to receive the lower limit comparison result and the upper limit comparison result, and the AND gate device outputs a control signal based on the lower limit comparison result and the upper limit comparison result.

10. The circuit according to claim 9, characterized in that The detection module also includes: A ninth resistor, wherein a first end of the ninth resistor is connected to the output end of the AND gate device, and a second end of the ninth resistor is connected to the power supply end of the servo.

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