Controller signal input circuit

Abstract

This invention provides a controller signal input circuit, comprising: a signal input terminal for receiving acquired signals, a channel selection circuit module, and a signal processing circuit module; the signal processing circuit module includes a digital signal processing unit and an analog signal processing unit; the channel selection circuit module sends the acquired signal to its first or second channel switching terminal based on the control signal received at its channel control terminal; the digital signal processing unit adjusts the acquired signal input at the first channel switching terminal into a digital input signal adapted to the controller of agricultural machinery and sends it to the controller through its first signal output terminal; the analog signal processing unit adjusts the acquired signal input at the second channel switching terminal into an analog input signal adapted to the controller and sends it to the controller through its second signal output terminal. The technical solution provided by this invention can achieve the acquisition and processing of multiple types of signals through only one signal input terminal, saving resources.

Description

Technical Field

[0001] This invention relates to the field of signal processing technology, and in particular to a controller signal input circuit. Background Technology

[0002] Agricultural machinery, also known as agricultural equipment, plays a vital role in agricultural production. Within agricultural machinery, signal acquisition and input circuits transmit collected input signals to a controller, such as a programmable logic controller (PLC), which then controls the operational status of the agricultural machinery based on the received signals.

[0003] Signal acquisition input circuits in agricultural machinery can include three types of input circuits: digital input circuits, voltage input circuits, and current input circuits. Currently, each input circuit has an independent input terminal, meaning each circuit has only one independent input terminal and can only use its own input terminal to receive signals. Therefore, if only one type of signal is input, the other input terminals will be idle, resulting in a waste of resources. Summary of the Invention

[0004] This invention provides a controller signal input circuit to solve the problem that in the prior art, each signal input circuit of agricultural machinery equipment needs to be equipped with an independent input terminal, which easily leads to resource waste.

[0005] This invention provides a controller signal input circuit for use in agricultural machinery. The controller signal input circuit includes a signal input terminal, a channel selection circuit module, and a signal processing circuit module. The signal processing circuit module includes a digital quantity processing unit, an analog quantity processing unit, a first signal output terminal, and a second signal output terminal.

[0006] The signal input terminal is used to receive the acquired signal;

[0007] The channel selection circuit module includes a signal receiving end, a channel control end, a first channel switching end, and a second channel switching end. The signal receiving end is connected to the signal input end. The channel control end is used to connect to the processor. The first channel switching end is connected to the digital quantity processing unit. The second channel switching end is connected to the analog quantity processing unit. The channel selection circuit module sends the acquired signal to the first channel switching end or the second channel switching end based on the control signal received by the channel control end.

[0008] The digital signal processing unit is used to adjust the acquisition signal input from the first channel switching terminal to a digital input signal adapted to the controller of the agricultural machinery equipment, and send the digital input signal to the controller through the first signal output terminal;

[0009] The analog signal processing unit is used to adjust the acquisition signal input from the second channel switching terminal into an analog input signal adapted to the controller, and send the analog input signal to the controller through the second signal output terminal.

[0010] According to a controller signal input circuit provided by the present invention, the channel selection circuit module further includes a first transistor, a second transistor, and a sampling resistor;

[0011] The emitter of the first transistor is connected to the signal input terminal, the base is connected to the channel control terminal, and the collector is connected to the first channel switching terminal.

[0012] The collector of the second transistor is connected to the signal input terminal and the second channel switching terminal, the base is connected to the channel control terminal, and the emitter is grounded through the sampling resistor.

[0013] When the control signal controls the first transistor to be turned on and the second transistor to be turned off, the acquired signal is transmitted to the digital signal processing unit through the first channel switching terminal; when the control signal controls the first transistor to be turned off and the second transistor to be turned on, the acquired signal is transmitted to the analog signal processing unit through the second channel switching terminal.

[0014] According to a controller signal input circuit provided by the present invention, the first transistor is a PNP transistor and the second transistor is an NPN transistor;

[0015] The first transistor is cut off when the control signal is high and turned on when the control signal is low;

[0016] The second transistor is turned on when the control signal is high and turned off when the control signal is low.

[0017] According to a controller signal input circuit provided by the present invention, the switching quantity processing unit includes a first filter circuit and an amplifier;

[0018] The first filtering circuit includes a first filtering input terminal and a first filtering output terminal. The first filtering input terminal is connected to the first channel switching terminal, and the first filtering output terminal is connected to the non-inverting input terminal of the amplifier. The first filtering circuit is used to perform amplitude adjustment and filtering processing on the acquisition signal transmitted by the first channel switching terminal.

[0019] The inverting input of the amplifier is connected to a reference voltage source that provides a reference voltage signal. The output of the amplifier is connected to the first signal output. The amplifier is used to compare the signal at the first filtered output with the reference voltage signal at the inverting input and output a digital input signal adapted to the controller through the first output.

[0020] According to a controller signal input circuit provided by the present invention, the analog signal processing unit includes a first signal processing circuit, a second signal processing circuit, and an analog selection switch. The analog selection switch includes a first selection terminal, a second selection terminal, and an analog output terminal, wherein the analog output terminal is connected to the second signal output terminal.

[0021] The first signal processing circuit includes a first input terminal and a first output terminal. The first input terminal is connected to the second channel switching terminal, and the first output terminal is connected to the first selection terminal. The first signal processing circuit is used to adjust the current amplitude and filter the signal input from the first input terminal to obtain an analog current signal adapted to the controller.

[0022] The second signal processing circuit includes a second input terminal and a second output terminal. The second input terminal is connected to the second channel switching terminal, and the second output terminal is connected to the second selection terminal. The second signal processing circuit is used to perform voltage amplitude adjustment and filtering on the signal input from the second input terminal to obtain an analog voltage signal adapted to the controller.

[0023] The analog selection switch is used to select the output signal of the first selection terminal or the second selection terminal according to the control signal.

[0024] According to a controller signal input circuit provided by the present invention, the analog signal processing unit further includes a fully differential amplifier circuit, which is used to differentially amplify the analog signal output from the analog output terminal and then input it to the controller through the second signal output terminal.

[0025] According to a controller signal input circuit provided by the present invention, the fully differential amplifier circuit adopts a rail-to-rail input and output operational amplifier.

[0026] According to a controller signal input circuit provided by the present invention, the first signal processing circuit includes a first voltage divider resistor, a second voltage divider resistor, a first filter capacitor, and a second filter capacitor.

[0027] One end of the first voltage divider resistor is connected to the first input terminal, and the other end is connected in series with the second voltage divider resistor, grounded, and connected to the first output terminal.

[0028] One end of the first filter capacitor is connected to the first input terminal, and the other end is grounded;

[0029] One end of the second filter capacitor is connected to the series node of the first voltage divider resistor and the second voltage divider resistor, and the other end is grounded.

[0030] According to a controller signal input circuit provided by the present invention, the second signal processing circuit includes a filter inductor, a third filter capacitor, a third voltage divider resistor, a fourth voltage divider resistor, and a fourth filter capacitor.

[0031] One end of the filter inductor is connected to the second input terminal, and the other end is connected in series with the third filter capacitor and then grounded.

[0032] One end of the third voltage divider resistor is connected to the series node of the filter inductor and the third filter capacitor, and the other end is connected to the fourth voltage divider resistor in series, grounded, and connected to the second output terminal.

[0033] One end of the fourth filter capacitor is connected to the series node of the third and fourth voltage divider resistors, and the other end is grounded.

[0034] According to a controller signal input circuit provided by the present invention, an electrostatic discharge (ESD) resistor is further included, and the signal input terminal is connected to ground through the ESD.

[0035] The controller signal input circuit provided by this invention receives and inputs the acquired signal to the channel selection circuit module through a single signal input terminal. Under the control of a control signal sent by the processor, the channel selection circuit module selects a signal processing channel for the acquired signal. Based on the selected signal channel, it performs either digital or analog signal processing. Digital signals can be input to the digital processing unit through a first channel switching terminal, where they are adjusted to a digital input signal suitable for the controller. Similarly, analog signals can be input to the analog processing unit through a second channel switching terminal, where they are adjusted to an analog input signal suitable for the controller. This allows the controller to control the operating status of agricultural machinery based on the received signals. Because multiple types of signals can be acquired and processed through a single signal input terminal, the number of ports is reduced, the printed circuit board (PCB) size is decreased, and resources are saved. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0037] Figure 1 This is one of the structural schematic diagrams of the controller signal input circuit provided by the present invention;

[0038] Figure 2 This is the second schematic diagram of the controller signal input circuit provided by the present invention;

[0039] Figure 3 This is a schematic diagram of the structure of the switch quantity processing unit provided by the present invention;

[0040] Figure 4 This is the third schematic diagram of the controller signal input circuit provided by the present invention;

[0041] Figure 5 This is a schematic diagram of the analog signal processing unit provided by the present invention;

[0042] Figure 6 This is the fourth schematic diagram of the controller signal input circuit provided by the present invention;

[0043] Figure 7 This is the fifth schematic diagram of the controller signal input circuit provided by the present invention. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention 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 invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0045] In agricultural machinery, sensors of different modes can be used to detect signals. The collected signals can include switching signals, analog current signals, and analog voltage signals. These signals are then transmitted to a microcontroller via an input circuit to control the machinery's operation. In related technologies, each type of sensor signal requires a separate input port in the input circuit; that is, three input ports are needed to complete the acquisition. Each input port can only acquire one type of signal. Therefore, if all signals are of the same type, such as switching signals, the other input ports become unusable, resulting in wasted resources.

[0046] Based on this, in this embodiment of the invention, a controller signal input circuit is designed, which concentrates the multiple input interfaces required in related technologies to complete various types of signal acquisition into one input port. The acquired signal is received through a signal input terminal and input to the channel selection circuit module. The channel selection circuit module selects a signal processing channel for the acquired signal. The signal is processed according to the selected signal processing channel. The switch signal can be input to the switch processing unit through the first channel switching terminal, and the switch processing unit adjusts it into a digital input signal suitable for the controller. The analog signal can be input to the analog processing unit through the second channel switching terminal, and the analog processing unit adjusts it into an analog input signal suitable for the controller, so that the controller can control the working state of the agricultural machinery equipment according to the received signal.

[0047] The following is combined with Figures 1-7 The controller signal input circuit provided by the present invention is described below, and the controller signal input circuit can be applied to agricultural machinery equipment.

[0048] Figure 1 This schematic diagram illustrates one of the structural schematics of the controller signal input circuit provided in an embodiment of the present invention. (Refer to...) Figure 1 As shown, the controller signal input circuit may include a signal input terminal IN, a channel selection circuit module 11, and a signal processing circuit module 12. The signal processing circuit module 12 may include a digital quantity processing unit 121, an analog quantity processing unit 122, a first signal output terminal Dout, and a second signal output terminal Aout. The first signal output terminal Dout can be connected to the controller's digital input channel, and the second signal output terminal Aout can be connected to the controller's analog input channel.

[0049] The signal input terminal IN can be used to receive acquired signals, such as any one of the following: switch signals, analog current signals, and analog voltage signals acquired by the sensor.

[0050] The channel selection circuit module 11 may include a signal receiving terminal In1, a channel control terminal G, a first channel switching terminal A1, and a second channel switching terminal A2. The signal receiving terminal In1 is connected to the signal input terminal IN. The channel control terminal G is used to connect to the processor and can receive control signals from the processor. The first channel switching terminal A1 is connected to the digital quantity processing unit 121, and the second channel switching terminal A2 is connected to the analog quantity processing unit 122. The channel selection circuit module 11 can send the acquired signal received by the signal input terminal IN to the first channel switching terminal A1 or the second channel switching terminal A2 based on the control signal received by the channel control terminal G. For example, users can control sensors connected to the signal input terminal IN to collect required signals through human-machine interaction devices such as operating handles, buttons, and touch screens of agricultural machinery. The collected signals are then input to the signal input terminal IN. Based on the user's control operation and the sensor's signal type, the processor can send a corresponding control signal to the channel control terminal G. The control channel selection circuit module 11 then sends the collected signal from the signal input terminal IN to the switch quantity processing unit 121 or analog quantity processing unit 122 in the signal processing circuit module 12 for processing, obtaining a digital or analog input signal adapted to the controller. For instance, if the sensor detects a switch quantity signal, the processor can send a control signal to the channel selection circuit module 11 to send the collected signal to the first channel switching terminal A1, triggering the switch quantity processing unit 121 to process the collected signal. Alternatively, if the sensor detects an analog quantity signal, the processor can send a control signal to the channel control terminal G to send the collected signal to the second channel switching terminal A2, triggering the analog quantity processing unit 122 to process the collected signal.

[0051] The digital input processing unit 121 adjusts the acquired signal input from the first channel switching terminal A1 into a digital input signal adapted to the controller of the agricultural machinery, and sends the digital input signal to the controller through the first signal output terminal Dout. The analog input processing unit 122 adjusts the acquired signal input from the second channel switching terminal A2 into an analog input signal adapted to the controller, and sends the analog input signal to the controller through the second signal output terminal Aout. The controller can control the working state of the agricultural machinery based on the received digital or analog input signal. The controller may be, for example, a programmable logic controller (PLC).

[0052] The controller signal input circuit provided by this invention, on the one hand, can realize the acquisition and processing of multiple types of signals through a single signal input terminal, saving the number of ports, reducing the layout size and overall volume of the PCB board and the number of interfaces, thus saving resources; on the other hand, with the same number of signal input terminals, it effectively improves the versatility of the product, can adapt to various models of agricultural machinery and equipment, and significantly reduces the use cost and control cost of agricultural machinery and equipment.

[0053] based on Figure 1 The controller signal input circuit corresponding to the embodiment, Figure 2 This schematic diagram illustrates a second structural diagram of the controller signal input circuit provided in an embodiment of the present invention, with reference to... Figure 2 As shown, the channel selection circuit module 11 of the controller signal input circuit also includes a first transistor Q1, a second transistor Q2, and a sampling resistor R1. The emitter of the first transistor Q1 is connected to the signal input terminal IN, the base is connected to the channel control terminal G, and the collector is connected to the first channel switching terminal A1. The collector of the second transistor Q2 is connected to both the signal input terminal IN and the second channel switching terminal A2, the base is connected to the channel control terminal G, and the emitter is grounded through the sampling resistor R1.

[0054] The channel control terminal G can receive control signals sent by the processor. When the control signal controls the first transistor Q1 to be turned on and the second transistor Q2 to be turned off, the acquisition signal input at the signal input terminal IN is transmitted to the digital quantity processing unit 121 through the first channel switching terminal A1. When the control signal controls the first transistor Q1 to be turned off and the second transistor Q2 to be turned on, the acquisition signal input at the signal input terminal IN is transmitted to the analog quantity processing unit 122 through the second channel switching terminal A2.

[0055] For example, the first transistor Q1 can be a PNP transistor, and the second transistor Q2 can be an NPN transistor. When the control signal at the channel control terminal G is high, the first transistor Q1 is cut off, the second transistor Q2 is turned on, and the acquired signal is transmitted to the analog signal processing unit 122 through the second channel switching terminal A2; when the control signal at the channel control terminal G is low, the first transistor Q1 is turned on, the second transistor Q2 is cut off, and the acquired signal is transmitted to the digital signal processing unit 121 through the first channel switching terminal A1.

[0056] In one example embodiment, Figure 3 The schematic diagram illustrates the structure of the switch quantity processing unit 121 provided in an embodiment of the present invention. (Refer to...) Figure 3As shown, the digital signal processing unit 121 may include a first filter circuit 311 and an amplifier 312. The first filter circuit 311 includes a first filter input terminal a1 and a first filter output terminal b1. The first filter input terminal a1 is connected to a first channel switching terminal A1, and the first filter output terminal b1 is connected to the non-inverting input terminal of the amplifier 312. The first filter circuit 311 is used to perform amplitude adjustment and filtering processing on the acquired signal transmitted through the first channel switching terminal A1.

[0057] For example, the first filter circuit 311 can be an RC filter circuit. For instance... Figure 3 As shown, the first filter circuit 311 may include a first resistor R31, a second resistor R32, a third resistor R33, a fifth filter capacitor C35, and a sixth filter capacitor C36. The first resistor R31 and the second resistor R32 are connected in series to the first filter output terminal b1; the third resistor R33 and the sixth filter capacitor C36 are connected in parallel, with one end connected to the first filter output terminal b1 and the other end grounded; one end of the fifth filter capacitor C35 is connected to the series node of the first resistor R31 and the second resistor R32, and the other end is grounded. The first filter circuit 311 can adjust the amplitude of the input signal at the first filter input terminal a1 by the voltage division of the first resistor R31, the second resistor R32, and the third resistor R33.

[0058] The first resistor R31, the second resistor R32, and the third resistor R33 divide the input signal at the first filter input terminal a1 by voltage division. This voltage division adjusts the amplitude of the input signal at the first filter input terminal a1 to match the voltage requirements of the back-end controller. By setting the values ​​of the first resistor R31, the second resistor R32, and the third resistor R33, the range of switch signals that the circuit can detect can be set. For example, if a switch signal of 0–36V needs to be acquired, appropriate voltage divider resistors can be selected based on the circuit structure.

[0059] The inverting input of amplifier 312 is connected to a reference voltage source, which can provide a reference voltage signal, such as a +1.65V reference voltage signal. The output of amplifier 312 is connected to the first signal output terminal Dout. Amplifier 312 can compare the signal at the first filtered output terminal b1 with the reference voltage signal at the inverting input terminal, and output a digital input signal adapted to the controller through the first output terminal Dout.

[0060] based on Figure 1 The controller signal input circuit corresponding to the embodiment, Figure 4 This schematic diagram illustrates the third structural diagram of the controller signal input circuit provided in an embodiment of the present invention, with reference to... Figure 4As shown, the analog signal input circuit of the controller may include a first signal processing circuit 411, a second signal processing circuit 412 and an analog selection switch 413. The analog selection switch 413 may include a first selection terminal F1, a second selection terminal F2 and an analog output terminal F3. The analog output terminal F3 is connected to the second signal output terminal Aout.

[0061] The first signal processing circuit 411 includes a first input terminal and a first output terminal. The first input terminal is connected to the second channel switching terminal A2, and the first output terminal is connected to the first selection terminal F1. The first signal processing circuit 411 can perform current amplitude adjustment and filtering on the signal input from the first input terminal to obtain an analog current signal adapted to the controller.

[0062] The second signal processing circuit 412 includes a second input terminal and a second output terminal. The second input terminal is connected to the second channel switching terminal A2, and the second output terminal is connected to the second selection terminal F2. The second signal processing circuit 412 can perform voltage amplitude adjustment and filtering on the signal input from the second input terminal to obtain an analog voltage signal adapted to the controller.

[0063] The analog selection switch 413 can select to output either the first selection terminal F1 or the second selection terminal F2 based on the control signal. For example, if the signal input terminal IN is connected to a current sensor, the processor can send a corresponding control signal to the channel control terminal G based on the user's operation to control the channel selection circuit module 11 to send the acquired signal from the signal input terminal IN to the second channel switching terminal A2. At the same time, the processor sends a first analog switch control signal to the analog selection switch 413 based on the control signal from the channel control terminal G, controlling the analog selection switch 413 to output the analog current signal of the first signal processing circuit 411. As another example, if the signal input terminal IN is connected to a voltage sensor, the channel selection circuit module 11 can be controlled by the channel control terminal G to send the acquired signal from the signal input terminal IN to the second channel switching terminal A2. Simultaneously, a second analog switch control signal is sent to the analog selection switch 413 based on the control signal from the channel control terminal G, controlling the analog selection switch 413 to output the analog voltage signal of the second signal processing circuit 412. For example, when the sensor connected to the signal input terminal IN is in switch mode, the processor can send a third analog switch control signal to the analog selection switch 413 to control the analog selection switch 413 to simultaneously turn off the signal output of the first selection terminal F1 and the second selection terminal F2.

[0064] In one example embodiment, Figure 5 This schematic diagram illustrates another structural schematic of the analog signal processing unit 122 provided in an embodiment of the present invention, with reference to... Figure 5 As shown, the analog signal processing unit 122 is compared to Figure 4It may also include a fully differential amplifier circuit 511, which can differentially amplify the analog signal output from the analog output terminal F3 of the analog selection switch 413, and input the processed signal to the controller through the second signal output terminal Aout. By connecting the fully differential amplifier circuit 511 to the analog output terminal F3 of the analog selection switch 413, common-mode interference can be effectively suppressed, and it can be ensured that the circuit can still collect the voltage drop when the signal input terminal IN receives a 0mA or 0V signal.

[0065] For example, the fully differential amplifier circuit 511 can employ rail-to-rail input and output operational amplifiers with extremely low offset voltage and extremely low input bias current, such as a maximum offset voltage of only 65uV and a maximum input bias current of only 1pA, and a rated temperature range, such as automotive-grade temperature range of -40° to +125°.

[0066] based on Figure 2 and Figure 4 The controller signal input circuit corresponding to the embodiment, Figure 6 The schematic diagram illustrates the fourth structural diagram of the controller signal input circuit provided in an embodiment of the present invention, with reference to... Figure 6 As shown, the first signal processing circuit 411 may include a first voltage divider resistor R61, a second voltage divider resistor R62, a first filter capacitor C61, and a second filter capacitor C62. One end of the first voltage divider resistor R61 is connected to the first input terminal of the first signal processing circuit 411, and the other end is connected in series with the second voltage divider resistor R62, grounded, and connected to the first output terminal. One end of the first filter capacitor C61 is connected to the first input terminal, and the other end is grounded. One end of the second filter capacitor C62 is connected to the series node of the first voltage divider resistor R61 and the second voltage divider resistor R62, and the other end is grounded.

[0067] The second signal processing circuit 412 may include a filter inductor L, a third filter capacitor C63, a third voltage divider resistor R63, a fourth voltage divider resistor R64, and a fourth filter capacitor C64. One end of the filter inductor L is connected to the second input terminal of the second signal processing circuit 412, and the other end is connected in series with the third filter capacitor C63 and then grounded. One end of the third voltage divider resistor R63 is connected to the series connection point of the filter inductor L and the third filter capacitor C63, and the other end is connected in series with the fourth voltage divider resistor R64, then grounded and connected to the second output terminal. One end of the fourth filter capacitor C64 is connected to the series connection point of the third voltage divider resistor R63 and the fourth voltage divider resistor R64, and the other end is grounded.

[0068] according to Figure 6The controller signal input circuit shown in the diagram, when it needs to acquire a switching signal, such as a switching voltage signal, through the signal input terminal IN, sends a low-level signal to the channel control terminal G. This low-level signal controls the first transistor Q1 to turn on and the second transistor Q2 to turn off. At this time, the switching signal at the signal input terminal IN is input to the switching processing unit 121 through the first channel switching terminal A1 and adjusted to a switching signal (i.e., a digital input signal) that is compatible with the voltage requirements of the back-end controller. Then, it is input to the controller through the first signal output terminal Dout.

[0069] When the signal input at the IN terminal is an analog signal, the analog current signal and the analog voltage signal can be switched by controlling the on / off state of the first transistor Q1 and the second transistor Q2 and by switching the analog selection switch 412.

[0070] For analog current signals, the processor sends a high-level signal to the channel control terminal G, and simultaneously controls the analog selection switch 413 to select the signal output of the first selection terminal F1. At this time, the first transistor Q1 is cut off and the second transistor Q2 is turned on. After the second transistor Q2 is turned on, it connects to the sampling resistor R1. The analog current signal is sampled by the sampling resistor R1 and input to the analog signal processing unit 122 through the second channel switching terminal A2. After being processed by the first signal processing circuit 411 through voltage division and filtering, it is selected by the analog selection switch 413 and input to the fully differential amplifier circuit 511 for differential amplification. After differential amplification, it is input to the controller through the second signal output terminal Aout. The first voltage dividing resistor R61 and the second voltage dividing resistor R62 can divide the signal transmitted through the second channel switching terminal A2. By adjusting the voltage division, the signal amplitude can be adapted to the voltage requirements of the back-end controller. By setting the resistance values ​​of the sampling resistor R1, the first voltage dividing resistor R61, and the second voltage dividing resistor R62, the range of analog current signals that the circuit can detect can be set. For example, when sampling a current of 0–30 mA, the first voltage divider resistor R61 and the second voltage divider resistor R62 can be 100KΩ resistors, and the sampling resistor R1 can be a 200Ω resistor. In this case, almost all the current flows through the parallel sampling resistor R1. Meanwhile, the first filter capacitor C61 and the second filter capacitor C62, together with the voltage divider resistors R61 and R62, form an RC filter circuit, which can improve the stability and anti-interference capability of the circuit.

[0071] For analog voltage signals, the processor sends a low-level signal to the channel control terminal G, and simultaneously controls the analog selection switch 413 to select the signal output of the second selection terminal F2. At this time, the first transistor Q1 is turned on and the second transistor Q2 is turned off. The acquired analog voltage signal is input to the analog signal processing unit 122 through the second channel switching terminal A2. After being processed by the second signal processing circuit 412 through voltage division and filtering, it is selected by the analog selection switch 413 and input to the fully differential amplifier circuit 511 for differential amplification. Then, it is input to the controller through the second signal output terminal Aout. The third voltage dividing resistor R63 and the fourth voltage dividing resistor R64 can divide the signal transmitted through the second channel switching terminal A2, adjusting the signal amplitude to match the voltage requirements of the back-end controller. By setting the resistance values ​​of the third voltage dividing resistor R63 and the fourth voltage dividing resistor R64, the range of analog voltage signals that the circuit can detect can be set. For example, when it is necessary to acquire a voltage of 0-36V, the appropriate resistance values ​​of the voltage dividing resistors can be set according to the circuit structure. The filter inductor L and the third filter capacitor C63 can form an LC filter circuit, and the fourth filter capacitor C64 can form an RC filter circuit with the third voltage divider resistor R63 and the fourth voltage divider resistor R64. Filtering can improve the stability and anti-interference ability of the circuit.

[0072] based on Figure 1 The controller signal input circuit corresponding to the embodiment, Figure 7 The fifth schematic diagram illustrates the structure of the controller signal input circuit provided in an embodiment of the present invention. (Refer to...) Figure 7 As shown, the controller signal input circuit is in Figure 1 In addition, an electrostatic discharge (ESD) resistor is added, through which the signal input terminal IN is connected to ground. This ESD acts as a protective device to prevent circuit damage caused by external interference.

[0073] The controller signal input circuit provided in this invention can acquire multiple signal modes, such as switching signals, analog voltage signals, and analog current signals, using only one signal input terminal, thus reducing the number of connector ports. On the one hand, it can increase the product's versatility by at least 3 times with the same number of signal input ports, adapting to various models of agricultural machinery and equipment, resulting in good versatility and significantly saving operating costs. On the other hand, it can effectively reduce the size of the PCB board, maximizing functionality and greatly saving material resources. Furthermore, multiple types of signals can be acquired using a single circuit board, exhibiting good compatibility with sensors and meeting the acquisition needs of almost all sensor signals, making it more convenient for users. Moreover, each type of signal has a dedicated signal processing channel, providing strong anti-interference capabilities. Additionally, the range of acquireable signals can be increased by setting the circuit device parameters; for example, it can acquire switching signals (0-36V), voltage signals (0-36V), and current signals (0-30mA).

[0074] The embodiments described above are merely illustrative, and some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement these embodiments without any creative effort.

[0075] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention 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 the present invention.

Claims

1. A controller signal input circuit, characterized in that, Applied to agricultural machinery and equipment, the controller signal input circuit includes a signal input terminal, a channel selection circuit module, and a signal processing circuit module. The signal processing circuit module includes a digital quantity processing unit, an analog quantity processing unit, a first signal output terminal, and a second signal output terminal. The signal input terminal is used to receive the acquired signal; The channel selection circuit module includes a signal receiving end, a channel control end, a first channel switching end, and a second channel switching end. The signal receiving end is connected to the signal input end. The channel control end is used to connect to the processor. The first channel switching end is connected to the digital quantity processing unit. The second channel switching end is connected to the analog quantity processing unit. The channel selection circuit module sends the acquired signal to the first channel switching end or the second channel switching end based on the control signal received by the channel control end. The digital signal processing unit is used to adjust the acquisition signal input from the first channel switching terminal to a digital input signal adapted to the controller of the agricultural machinery equipment, and send the digital input signal to the controller through the first signal output terminal; The analog signal processing unit is used to adjust the acquisition signal input from the second channel switching terminal into an analog input signal adapted to the controller, and send the analog input signal to the controller through the second signal output terminal.

2. The controller signal input circuit according to claim 1, characterized in that, The channel selection circuit module also includes a first transistor, a second transistor, and a sampling resistor; The emitter of the first transistor is connected to the signal input terminal, the base is connected to the channel control terminal, and the collector is connected to the first channel switching terminal. The collector of the second transistor is connected to the signal input terminal and the second channel switching terminal, the base is connected to the channel control terminal, and the emitter is grounded through the sampling resistor. When the control signal controls the first transistor to be turned on and the second transistor to be turned off, the acquired signal is transmitted to the digital signal processing unit through the first channel switching terminal; when the control signal controls the first transistor to be turned off and the second transistor to be turned on, the acquired signal is transmitted to the analog signal processing unit through the second channel switching terminal.

3. The controller signal input circuit according to claim 2, characterized in that, The first transistor is a PNP transistor, and the second transistor is an NPN transistor; The first transistor is cut off when the control signal is high and turned on when the control signal is low; The second transistor is turned on when the control signal is high and turned off when the control signal is low.

4. The controller signal input circuit according to claim 1, characterized in that, The switching quantity processing unit includes a first filter circuit and an amplifier; The first filtering circuit includes a first filtering input terminal and a first filtering output terminal. The first filtering input terminal is connected to the first channel switching terminal, and the first filtering output terminal is connected to the non-inverting input terminal of the amplifier. The first filtering circuit is used to perform amplitude adjustment and filtering processing on the acquisition signal transmitted by the first channel switching terminal. The inverting input of the amplifier is connected to a reference voltage source that provides a reference voltage signal. The output of the amplifier is connected to the first signal output. The amplifier is used to compare the signal at the first filtered output with the reference voltage signal at the inverting input and output a digital input signal adapted to the controller through the first output.

5. The controller signal input circuit according to claim 1, characterized in that, The analog signal processing unit includes a first signal processing circuit, a second signal processing circuit, and an analog selection switch. The analog selection switch includes a first selection terminal, a second selection terminal, and an analog output terminal. The analog output terminal is connected to the second signal output terminal. The first signal processing circuit includes a first input terminal and a first output terminal. The first input terminal is connected to the second channel switching terminal, and the first output terminal is connected to the first selection terminal. The first signal processing circuit is used to adjust the current amplitude and filter the signal input from the first input terminal to obtain an analog current signal adapted to the controller. The second signal processing circuit includes a second input terminal and a second output terminal. The second input terminal is connected to the second channel switching terminal, and the second output terminal is connected to the second selection terminal. The second signal processing circuit is used to perform voltage amplitude adjustment and filtering on the signal input from the second input terminal to obtain an analog voltage signal adapted to the controller. The analog selection switch is used to select the output signal of the first selection terminal or the second selection terminal according to the control signal.

6. The controller signal input circuit according to claim 5, characterized in that, The analog signal processing unit further includes a fully differential amplifier circuit, which is used to differentially amplify the analog signal output from the analog output terminal and then input it to the controller through the second signal output terminal.

7. The controller signal input circuit according to claim 6, characterized in that, The fully differential amplifier circuit uses rail-to-rail input and output operational amplifiers.

8. The controller signal input circuit according to claim 5, characterized in that, The first signal processing circuit includes a first voltage divider resistor, a second voltage divider resistor, a first filter capacitor, and a second filter capacitor; One end of the first voltage divider resistor is connected to the first input terminal, and the other end is connected in series with the second voltage divider resistor, grounded, and connected to the first output terminal. One end of the first filter capacitor is connected to the first input terminal, and the other end is grounded; One end of the second filter capacitor is connected to the series node of the first voltage divider resistor and the second voltage divider resistor, and the other end is grounded.

9. The controller signal input circuit according to claim 5, characterized in that, The second signal processing circuit includes a filter inductor, a third filter capacitor, a third voltage divider resistor, a fourth voltage divider resistor, and a fourth filter capacitor; One end of the filter inductor is connected to the second input terminal, and the other end is connected in series with the third filter capacitor and then grounded. One end of the third voltage divider resistor is connected to the series node of the filter inductor and the third filter capacitor, and the other end is connected to the fourth voltage divider resistor in series, grounded, and connected to the second output terminal. One end of the fourth filter capacitor is connected to the series node of the third and fourth voltage divider resistors, and the other end is grounded.

10. The controller signal input circuit according to claim 1, characterized in that, It also includes an electrostatic discharge (ESD) resistor, through which the signal input terminal is connected to ground.

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