Zero-gravity seat motor safety detection circuit

Abstract

The utility model is suitable for the technical field of seat posture control, and provides a zero-gravity seat motor safety detection circuit which is used for detecting the working current of a posture control motor through a current sampling resistor; the operational amplifier circuit is connected with the current sampling resistor so as to carry out operational output on the current output by the current sampling resistor; and the controller is used for acquiring the safety state of the attitude control motor through the operation signal output by the operation amplification circuit, so that the controller is used for judging whether abnormal conditions such as overcurrent and short circuit occur in the motor or not. For example, when the controller detects that the sampled current value exceeds the set value, it can be judged that the corresponding motor has overcurrent and short circuit faults, and at the moment, a control signal needs to be output to control the corresponding motor to stop working, so that safety protection control is conducted on the motor and the seat, and the safety problem of the motor is avoided.

Description

Technical Field

[0001] The utility model belongs to the technical field of seat posture control, and in particular relates to a zero-gravity seat motor safety detection circuit. Background Art

[0002] All parts of the zero-gravity seat need to be adjusted and controlled by various motors to ensure the seat is in the best condition, to suppress the discomfort caused to the passengers by the earth's gravity to a certain extent, to place the center of gravity of the human body in one place, and to free other parts of the body from pressure, making it more comfortable.

[0003] Since the adjustment motors in various parts of the seat are subject to different pressures, the pressure borne by the motor for adjusting the headrest may be relatively small, but the pressure borne by the motor for adjusting the backrest and seat cushion is relatively large, so a larger power motor is needed to drive it. When the motor current is too large, a short circuit problem is likely to occur, which will pose a certain safety hazard. Therefore, the utility model proposes a zero-gravity seat motor safety detection circuit to solve the above problem. Utility Model Content

[0004] The utility model provides a zero-gravity chair motor safety detection circuit, aiming to solve the problems raised by the background technology.

[0005] The utility model is implemented in this way: a zero-gravity chair motor safety detection circuit comprises:

[0006] A current sampling resistor, wherein the current sampling resistor is used to detect the working current of the attitude control motor;

[0007] An operational amplifier circuit, the operational amplifier circuit is connected to the current sampling resistor to perform operation and output the current output by the current sampling resistor;

[0008] A controller, the controller is used to obtain the safety state of the attitude control motor through the operation signal output by the operational amplifier circuit;

[0009] The controller is connected to the posture control motor through the motor drive circuit to drive and control the posture control motor.

[0010] Preferably, the operational amplifier circuit includes a first operational amplifier, a non-inverting input terminal of the first operational amplifier is connected to one end of a first resistor, the other end of the first resistor is connected to one end of a second resistor, the other end of the second resistor is connected to a current sampling output terminal of the current sampling resistor, a reverse input terminal of the first operational amplifier is connected to one end of a third resistor, the other end of the third resistor is connected to a reference ground via a fourth resistor, and the reverse input terminal of the first operational amplifier is also connected to the output terminal of the first operational amplifier via a fifth resistor.

[0011] Preferably, the operational amplifier circuit further includes a bias voltage circuit, and the bias voltage circuit is connected to the non-inverting input terminal of the first operational amplifier to provide a bias voltage for the non-inverting input terminal of the first operational amplifier.

[0012] Preferably, the bias voltage circuit comprises:

[0013] a sixth resistor, one end of which is connected to the power supply;

[0014] a seventh resistor, the other end of the seventh resistor being connected to the other end of the sixth resistor, and the other end of the seventh resistor being connected to a reference ground;

[0015] A second operational amplifier, wherein the non-inverting input terminal of the second operational amplifier is connected to the common terminal of the seventh resistor and the sixth resistor, the inverting input terminal of the second operational amplifier is connected to the output terminal of the second operational amplifier, and the output terminal of the second operational amplifier is connected to the non-inverting input terminal of the first operational amplifier through the eighth resistor.

[0016] Preferably, the bias voltage circuit further includes:

[0017] A first capacitor, one end of the first capacitor is connected to the power supply, and the other end of the first capacitor is connected to a reference ground;

[0018] a second capacitor, one end of the second capacitor being connected to the non-inverting input terminal of the second operational amplifier, and the other end of the second capacitor being connected to a reference ground;

[0019] A third capacitor, one end of the third capacitor is connected to the output end of the second operational amplifier, and the other end of the third capacitor is connected to a reference ground.

[0020] Preferably, the operational amplifier circuit further includes an output voltage clamping circuit, and the output voltage clamping circuit is connected to the output end of the first operational amplifier to clamp the output voltage of the second operational amplifier within a preset voltage range.

[0021] Preferably, the output voltage clamping circuit comprises:

[0022] a diode, wherein an anode of the diode is connected to the output end of the first operational amplifier through a ninth resistor, and a cathode of the diode is connected to a pull-up voltage;

[0023] A transient diode, one end of which is connected to the output end of the first operational amplifier, and the other end of which is connected to a reference ground;

[0024] A fourth capacitor, one end of the fourth capacitor is connected to the output end of the first operational amplifier, and the other end of the transient diode is connected to a reference ground.

[0025] Preferably, the motor drive circuit includes a relay switch, the first control end and the second control end of the relay switch are respectively connected to the main control circuit, the first drive signal end and the second drive signal end of the relay switch are respectively connected to the posture control motor, and the current sampling resistor is connected in series to the drive signal loop of the posture control motor through the relay switch.

[0026] Preferably, the motor drive circuit also includes a motor interface circuit, which includes a motor interface, wherein the first motor connection end of the motor interface is connected to the first drive signal output end of the relay switch, the second motor connection end of the motor interface is connected to the second drive signal output end of the relay switch, and the first motor connection end and the second motor connection end of the motor interface are also respectively connected to the posture control motor.

[0027] Compared with the prior art, the beneficial effects of the utility model are:

[0028] The zero-gravity seat motor safety detection circuit provided by the patent of the present invention is used to detect the working current of the posture control motor through the current sampling resistor; the operational amplifier circuit is connected to the current sampling resistor to perform operation and output the current output by the current sampling resistor; the controller is used to obtain the safety state of the posture control motor through the operation signal output by the operational amplifier circuit, so that the controller can judge whether the motor has abnormal conditions such as overcurrent and short circuit. For example, when the controller detects that the sampled current value exceeds the set value, it can be judged that the corresponding motor has an overcurrent or short circuit fault. At this time, a control signal should be output to control the corresponding motor to stop working, so as to perform safety protection control on the motor and the seat to avoid safety problems with the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The block diagram of the zero-gravity seat motor safety detection circuit provided by the patent of this invention;

[0030] Figure 2 A schematic diagram of the circuit structure of the motor interface circuit provided by the patent of the present invention;

[0031] Figure 3 A schematic diagram of the circuit structure of the motor drive circuit and the current sampling resistor provided by the patent of the present invention;

[0032] Figure 4 A schematic diagram of the operational amplifier circuit and output voltage clamp circuit structure provided by the patent of this invention;

[0033] Figure 5 This is a schematic diagram of the bias voltage circuit structure provided by the patent of this invention.

[0034] In the figure:

[0035] K1, relay switch; CN6, motor interface; U7A, first operational amplifier; U7B, second operational amplifier; R20, eighth resistor; R21, sixth resistor; R22, second resistor; R23, first resistor; R26, ninth resistor; R27, seventh resistor; R28, fourth resistor; R29, third resistor; R30, fifth resistor; C49, second capacitor; C50, first capacitor; D3, diode; VD3, transient diode. DETAILED DESCRIPTION

[0036] The technical solution of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present utility model, rather than all of the embodiments.

[0037] The components of the embodiments of the present invention generally described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention.

[0038] Based on the embodiments of the present utility model, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present utility model.

[0039] 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.

[0040] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] See also Figures 1 to 5 The utility model provides a technical solution: a zero-gravity chair motor safety detection circuit, including a current sampling resistor, an operational amplifier circuit and a controller, wherein the current sampling resistor is used to detect the working current of the posture control motor; the operational amplifier circuit is connected to the current sampling resistor to perform an operation and output the current output by the current sampling resistor; the controller is used to obtain the safety state of the posture control motor through the operation signal output by the operational amplifier circuit.

[0042] Specifically, each part of the zero-gravity seat needs to be adjusted and controlled by various motors to ensure the best condition of the seat and to suppress the discomfort caused by the earth's gravity to the passengers to a certain extent. By placing the center of gravity of the human body in one place, other parts of the body are not under pressure, so it is more comfortable; because the adjustment motors in various parts of the seat have to bear different pressures; the pressure borne by the motor for adjusting the headrest may be relatively small, but the pressure borne by the motor for adjusting the backrest and seat cushion is relatively large, so a higher-power motor is needed to drive it. When the motor current is too large, it is easy to cause a short circuit problem, which will have certain safety hazards; therefore, it is necessary to detect the current of each posture control motor of the zero-gravity seat to ensure the safety of the seat;

[0043] like Figure 1 and Figure 3 As shown in , the current sampling resistor R24 ​​is set in the driving current loop of the motor, so that the current value of the motor during operation can be sampled, such as Figure 3 As shown, the sampled current value is output to the operational amplifier circuit through the IV-1 signal terminal for operational processing, and then output to the controller, through which the controller can determine whether the motor has abnormal conditions such as overcurrent and short circuit; for example, when the controller detects that the sampled current value exceeds the set value, it can be determined that the corresponding motor has an overcurrent or short circuit fault, and at this time, a control signal should be output to control the corresponding motor to stop working, so as to protect the motor and the seat;

[0044] See also Figures 1 to 3The zero-gravity seat motor safety detection circuit also includes a motor drive circuit, and the controller is connected to the attitude control motor through the motor drive circuit to drive and control the attitude control motor. Figure 1 As shown in , the attitude control motor is driven by a motor drive circuit; wherein the controller outputs a control signal to the motor drive circuit, and controls the rotation of the corresponding attitude control motor through the drive circuit;

[0045] like Figure 3 As shown in, the motor drive circuit includes: a relay switch K1, a first control end and a second control end of the relay switch K1 are respectively connected to the main control circuit, a first drive signal end Motor-1+ and a second drive signal end Motor-1- of the relay switch K1 are respectively connected to the attitude control motor, a current sampling resistor R24 ​​is connected in series to the drive signal loop of the attitude control motor through the relay switch K1, a controller controls the relay switch K1 by outputting DJ_UH-1 and DJ_UL-1 control signals, and the relay switch K1 can be connected to the motor through the Motor-1+ and Motor-1- signal ends of the motor interface CN6, and the motor is driven to rotate through the Motor-1+ and Motor-1- signal ends; wherein, the relay switch K1 constitutes an H-bridge circuit, when the first control end DJ_UH-1 is a low level signal and DJ_UL-1 is a high level signal, the Motor-1+ signal end can be connected to the +12V power supply, and the Motor-1- signal end can be connected to the +12V power supply through the resistor R 24 is connected to the reference ground, so that the drive circuit of the motor is connected, and the motor rotates in the positive direction. On the contrary, when the first control terminal DJ_UH-1 is a high-level signal and DJ_UL-1 is a low-level signal, the motor rotates in the reverse direction, and the motor does not rotate in other states; in this way, the rotation of the motor can be controlled, and the current sampling resistor R24 ​​is connected in series to the drive signal circuit of the attitude control motor through the relay switch K1. When the attitude control motor starts to work, there is a drive current on the drive signal circuit of the attitude control motor. The current of the attitude control motor when working can be collected through the current sampling resistor R24, and output to the operational amplifier circuit through the IV-1 signal terminal. After isolation operation by the operational amplifier circuit, it is output to the controller to determine whether the motor has an abnormal situation such as overcurrent or short circuit; for example, when the controller detects that the sampled current value exceeds the set value, it can be determined that the corresponding motor has an overcurrent or short circuit fault. At this time, a control signal should be output to control the corresponding motor to stop working, so as to protect the motor and the seat safely;

[0046] like Figure 2As shown in , the zero-gravity chair motor safety detection circuit also includes: a motor interface circuit, the motor interface circuit includes a motor interface CN6, a first motor connection end of the motor interface CN6 is connected to the first drive signal output end Motor-1+ of the relay switch K1, a second motor connection end of the motor interface CN6 is connected to the second drive signal output end Motor-1- of the relay switch K1, the first motor connection end and the second motor connection end of the motor interface CN6 are also respectively connected to the posture control motor, and can be connected to the signal end of the posture control motor through the motor interface CN6, so that the posture control motor can be conveniently connected, and at the same time, the relay switch K1 can output a drive signal to the posture control motor through the motor interface CN6 to drive the rotation;

[0047] See also Figure 4 The operational amplifier circuit includes: a first operational amplifier U7A, a non-inverting input terminal of the first operational amplifier U7A is connected to one end of a first resistor R23, the other end of the first resistor R23 is connected to one end of a second resistor R22, the other end of the second resistor R22 is connected to a current sampling output terminal of a current sampling resistor R24, a reverse input terminal of the first operational amplifier U7A is connected to one end of a third resistor R29, the other end of the third resistor R29 is connected to a reference ground through a fourth resistor R28, and the reverse input terminal of the first operational amplifier U7A is also connected to the output terminal of the first operational amplifier U7A through a fifth resistor R30; specifically, as Figure 4 As shown in , the first operational amplifier U7A forms an operational circuit by connecting resistors, and the current sampling resistor R24 ​​uses the output current signal IV-1 to perform isolation operational amplification and output it to the controller to meet the sampling requirements of the controller;

[0048] See also Figure 1 , Figure 4 and Figure 5 The zero-gravity seat motor safety detection circuit also includes a bias voltage circuit, which is connected to the non-phase input terminal of the first operational amplifier U7A to provide a bias voltage for the non-phase input terminal of the first operational amplifier U7A. Since the first operational amplifier U7A is a single-power-supply operational amplifier, and the rotation direction of the motor may be a positive direction or a reverse direction, when the motor rotates in the positive direction, the current signal IV-1 is a positive voltage output, and when the motor rotates in the reverse direction, the current signal IV-1 is a negative voltage output. When the current signal IV-1 is a negative voltage output, the signal output requirement of the first operational amplifier U7A powered by a single power supply cannot be met. A positive voltage is connected to the non-phase input terminal of the first operational amplifier U7A through the bias voltage circuit, and the signal output requirement of the first operational amplifier U7A powered by a single power supply can be met by superimposing it with the current signal IV-1;

[0049] like Figure 4 and Figure 5 As shown in, the bias voltage circuit includes: a sixth resistor R21, a seventh resistor R27 and a second operational amplifier U7B, one end of the sixth resistor R21 is connected to the power supply, the other end of the seventh resistor R27 is connected to the other end of the sixth resistor R21, and the other end of the seventh resistor R27 is connected to the reference ground; the positive input end of the second operational amplifier U7B is connected to the common end of the seventh resistor R27 and the sixth resistor R21, the inverting input end of the second operational amplifier U7B is connected to the output end of the second operational amplifier U7B, and the output end of the second operational amplifier U7B is connected to the positive input end of the first operational amplifier U7A through the eighth resistor R20; wherein, a voltage divider circuit can be formed by the sixth resistor R21 and the seventh resistor R27, and the 3.3V input voltage is divided and output to the positive input end of the second operational amplifier U7B, and the second operational amplifier U7B forms a voltage follower, and the voltage divided and output by the sixth resistor R21 and the seventh resistor R27 is isolated and output, and output to the positive input end of the second operational amplifier U7B through the eighth resistor R20;

[0050] See also Figure 5 In one embodiment of the present invention, the bias voltage circuit further includes: a first capacitor C50, a second capacitor C49 and a third capacitor C51, one end of the first capacitor C50 is connected to the power supply, the other end of the first capacitor C50 is connected to the reference ground, one end of the second capacitor C49 is connected to the non-inverting input terminal of the second operational amplifier U7B, the other end of the second capacitor C49 is connected to the reference ground, one end of the third capacitor C51 is connected to the output terminal of the second operational amplifier U7B, and the other end of the third capacitor C51 is connected to the reference ground; Figure 5 As shown in, by connecting capacitors in parallel to each signal or power supply end, interference signals can be filtered out to ensure the problem of power supply or signal, wherein the first capacitor C50 can filter out interference signals at the 3.3V power supply end, the third capacitor C51 can filter out interference signals at the non-inverting input end of the second operational amplifier U7B, and the third capacitor C51 and capacitor C52 can filter out interference signals at the output end of the second operational amplifier U7B;

[0051] See also Figure 1 and Figure 4 In one embodiment of the present invention, the zero-gravity chair motor safety detection circuit further includes: an output voltage clamping circuit, which is connected to the output end of the first operational amplifier U7A to clamp the output voltage of the second operational amplifier U7B within a preset voltage range. In order to avoid damage to the controller by the abnormal pulse signal at the output end of the first operational amplifier U7A, the output signal of the first operational amplifier U7A can be clamped within a voltage range of 0 to 3.3V through the output voltage clamping circuit;

[0052] like Figure 4 As shown in, the output voltage clamping circuit includes: a diode D3, a transient diode VD3 and a fourth capacitor C54, the anode of the diode D3 is connected to the output end of the first operational amplifier U7A through the ninth resistor R26, and the cathode of the diode D3 is connected to the pull-up voltage; one end of the transient diode VD3 is connected to the output end of the first operational amplifier U7A, and the other end of the transient diode VD3 is connected to the reference ground; one end of the fourth capacitor C54 is connected to the output end of the first operational amplifier U7A, and the other end of the transient diode VD3 is connected to the reference ground; when the output end of the second operational amplifier U7B generates an abnormal signal and the signal voltage value is greater than 3.3V, the diode D3 can be turned on, so that the signal CURT-1 output to the controller does not exceed 3.3V. When the abnormal signal is very large, the transient diode VD3 can be turned on quickly, and the electricity can be quickly released to the ground to ensure that the controller is not damaged. The fourth capacitor C54 can filter out high-frequency signals to ensure the stability of the CURT-1 signal.

[0053] The working principle and use process of the utility model are as follows: the provided zero-gravity seat motor safety detection circuit is used to detect the working current of the posture control motor through a current sampling resistor; the operational amplifier circuit is connected to the current sampling resistor to perform operational output on the current output by the current sampling resistor; the controller is used to obtain the safety state of the posture control motor through the operational signal output by the operational amplifier circuit, so that the controller can determine whether the motor has abnormal conditions such as overcurrent and short circuit; for example, when the controller detects that the sampled current value exceeds the set value, it can be determined that the corresponding motor has an overcurrent or short circuit fault. At this time, a control signal should be output to control the corresponding motor to stop working, so as to perform safety protection control on the motor and the seat to avoid safety problems with the motor.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A zero gravity seat motor safety detection circuit, characterized in that: include: A current sampling resistor, wherein the current sampling resistor is used to detect the working current of the attitude control motor; An operational amplifier circuit, the operational amplifier circuit is connected to the current sampling resistor to perform operation and output the current output by the current sampling resistor; A controller, the controller is used to obtain the safety state of the attitude control motor through the operation signal output by the operational amplifier circuit; The controller is connected to the posture control motor through the motor drive circuit to drive and control the posture control motor.

2. The zero-gravity chair motor safety detection circuit according to claim 1, characterized in that: The operational amplifier circuit comprises a first operational amplifier (U7A), a non-inverting input terminal of the first operational amplifier (U7A) is connected to one end of a first resistor (R23), the other end of the first resistor (R23) is connected to one end of a second resistor (R22), the other end of the second resistor (R22) is connected to a current sampling output terminal of the current sampling resistor, a reverse input terminal of the first operational amplifier (U7A) is connected to one end of a third resistor (R29), the other end of the third resistor (R29) is connected to a reference ground via a fourth resistor (R28), and the reverse input terminal of the first operational amplifier (U7A) is also connected to the output terminal of the first operational amplifier (U7A) via a fifth resistor (R30).

3. The zero-gravity chair motor safety detection circuit according to claim 2, characterized in that: The operational amplifier circuit also includes a bias voltage circuit, which is connected to the non-inverting input terminal of the first operational amplifier (U7A) to provide a bias voltage for the non-inverting input terminal of the first operational amplifier (U7A).

4. The zero-gravity chair motor safety detection circuit according to claim 3, characterized in that: The bias voltage circuit comprises: a sixth resistor (R21), one end of the sixth resistor (R21) being connected to a power supply; a seventh resistor (R27), the other end of the seventh resistor (R27) being connected to the other end of the sixth resistor (R21), and the other end of the seventh resistor (R27) being connected to a reference ground; A second operational amplifier (U7B), wherein a non-inverting input terminal of the second operational amplifier (U7B) is connected to a common terminal of the seventh resistor (R27) and the sixth resistor (R21), an inverting input terminal of the second operational amplifier (U7B) is connected to an output terminal of the second operational amplifier (U7B), and an output terminal of the second operational amplifier (U7B) is connected to a non-inverting input terminal of the first operational amplifier (U7A) via an eighth resistor (R20).

5. The zero-gravity chair motor safety detection circuit according to claim 4, characterized in that: The bias voltage circuit also includes: A first capacitor (C50), one end of the first capacitor (C50) is connected to the power supply, and the other end of the first capacitor (C50) is connected to a reference ground; a second capacitor (C49), one end of the second capacitor (C49) being connected to the non-inverting input end of the second operational amplifier (U7B), and the other end of the second capacitor (C49) being connected to a reference ground; A third capacitor (C51), one end of the third capacitor (C51) is connected to the output end of the second operational amplifier (U7B), and the other end of the third capacitor (C51) is connected to a reference ground.

6. The zero-gravity chair motor safety detection circuit according to claim 4, characterized in that: The operational amplifier circuit also includes an output voltage clamping circuit, which is connected to the output end of the first operational amplifier (U7A) to clamp the output voltage of the second operational amplifier (U7B) within a preset voltage range.

7. The zero-gravity chair motor safety detection circuit according to claim 6, characterized in that: The output voltage clamping circuit comprises: a diode (D3), wherein an anode of the diode (D3) is connected to the output end of the first operational amplifier (U7A) via a ninth resistor (R26), and a cathode of the diode (D3) is connected to a pull-up voltage; a transient diode (VD3), one end of which is connected to the output end of the first operational amplifier (U7A), and the other end of which is connected to a reference ground; and a fourth capacitor (C54), one end of which is connected to the output end of the first operational amplifier (U7A), and the other end of which is connected to a reference ground.

8. The zero-gravity chair motor safety detection circuit according to claim 1, characterized in that: The motor drive circuit comprises a relay switch (K1), a first control end and a second control end of the relay switch (K1) are respectively connected to a main control circuit, a first drive signal end and a second drive signal end of the relay switch (K1) are respectively connected to the attitude control motor, and the current sampling resistor is connected in series to the drive signal loop of the attitude control motor through the relay switch (K1).

9. The zero-gravity chair motor safety detection circuit according to claim 8, characterized in that: The motor drive circuit also includes a motor interface circuit, which includes a motor interface (CN6), a first motor connection end of the motor interface (CN6) is connected to a first drive signal output end of the relay switch (K1), a second motor connection end of the motor interface (CN6) is connected to a second drive signal output end of the relay switch (K1), and the first motor connection end and the second motor connection end of the motor interface (CN6) are also respectively connected to the posture control motor.

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