Epb switch input device, epb controller, electronic parking brake control system and method

Abstract

The application provides an EPB switch input device, an EPB controller, an electronic parking control system and a method. The EPB switch input device comprises a control unit and an EPB switch input circuit with a controllable pull-up resistor sub-circuit and a controllable pull-down resistor sub-circuit. The first end of each EPB switch input circuit is connected with the output port of the corresponding EPB switch, and the second end is connected with the control unit. The control unit is used for sequentially changing the on and off states of the pull-down resistor sub-circuit and the controllable pull-up resistor sub-circuit of all EPB switch input circuits and obtaining the output level state of all EPB switch input circuits in each state to obtain the output level combination result in the same polling cycle; and according to the output level combination result and the EPB switch input circuit output level-EPB switch input state preset corresponding relationship, the current input state of the EPB switch is recognized and / or the fault of the EPB switch is diagnosed. The application can not only separate the selection of the EPB switch and the motor control device, so that the design of the motor controller is more flexible, but also can reduce the risk of insufficient production capacity caused by the shortage of chips with EPB switch input reading function.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle control, in particular to an EPB switch input device, an EPB controller, an electronic parking brake control system and a method. BACKGROUND

[0002] The EPB (Electrical Park Brake) switch replaces the mechanical hand brake in the whole vehicle, and locks the wheels through the mechanical structure connected to the original driver's mechanical hand brake rod, and changes the driver's need to pull up or press down the EPB switch to easily realize the tightening and release of the wheel end caliper, so as to achieve the purpose of parking. Moreover, due to the addition of the motor, the EPB can also realize various functions such as automatic parking, and therefore the EPB switch gradually becomes one of the key components of the vehicle.

[0003] However, the structure of the EPB switch is not the common input of high and low level, PWM input or analog signal input, but an input of mutual connection relationship. Exemplarily, please refer to Figure 1 and Figure 2 , wherein, Figure 1 is a specific example structure diagram of the EPB switch in the related art; Figure 2 is Figure 1 is a schematic diagram of the connection relationship of the EPB switch in different states. As can be seen from Figure 1 , the EPB switch mainly includes a switch body (not shown in the figure) with "Apply" and "Release" buttons as shown in Figure 1 , and a connection line (not marked in the figure) with four output ports, i.e. a first output port EPB_SW1, a second output port EPB_SW2, a third output port EPB_SW3 and a fourth output port EPB_SW4. When the driver operates the EPB switch (such as pressing the "Apply" or "Release" button), the connection state of the connection line will be changed, and the controller can recognize the intention of the driver inputting the EPB switch by judging the connection state of the four output ports of the EPB switch, i.e. the first output port EPB_SW1, the second output port EPB_SW2, the third output port EPB_SW3 and the fourth output port EPB_SW4, and then control the vehicle brake to perform corresponding actions, and can also judge the error connection relationship in the fault state. The connection relationship of the four output ports is different when the EPB switch is in different input states, such as Figure 2As shown: when the EPB switch is in the neutral (i.e. zero) state, the first output port EPB_SW1 and the third output port EPB_SW3 are connected, and the second output port EPB_SW2 and the fourth output port EPB_SW4 are connected; when the EPB switch is in the tightening (i.e. pulling up) state, the first output port EPB_SW1, the second output port EPB_SW2 and the fourth output port EPB_SW4 are connected; when the EPB switch is in the release state, the first output port EPB_SW1, the third output port EPB_SW3 and the fourth output port EPB_SW4 are connected. At present, the mainstream scheme for reading the state of the EPB switch is to read through an integrated chip, and this scheme has the following defects:

[0004] On the one hand, at present, the chip with the input reading scheme of the EPB switch is only a few chips of one chip company, and the chip integrates multiple functions such as EPB switch input and motor controller, and is aimed at the architecture of the mainstream electric brake system, and is not friendly to other brake architectures, and the design flexibility is low. On the other hand, due to the single supplier, once the chip is short in supply or for other reasons, it is difficult to continue production by finding alternative materials, and there is a risk of shortage of chips with EPB switch input reading function leading to insufficient production capacity.

[0005] It should be noted that the information disclosed in the background section of the present application is only intended to deepen the understanding of the general background of the present application, and should not be regarded as acknowledging or implying in any form that the information constitutes prior art known to those skilled in the art. SUMMARY

[0006] The present application aims to solve one or more problems of high integration, poor flexibility and high dependence in reading the input state of the EPB switch in the prior art, and provides an EPB switch input device, an EPB controller, an electronic parking control system and a method. The present application not only enables the EPB switch and the motor controller to be selected separately, making the design of the motor controller more flexible, but also reduces the risk of insufficient production capacity caused by shortage of chips with EPB switch input reading function.

[0007] In order to achieve the above-mentioned purpose, the present application realizes the following technical scheme, an EPB switch input device for an EPB switch, the EPB switch input device comprising an EPB switch input circuit and a control unit, the number of the EPB switch input circuits being the same as the number of output ports of the EPB switch; a first end of the EPB switch input circuit is configured to be connected to the corresponding output port, and a second end of the EPB switch input circuit is connected to the control unit; the EPB switch input circuit comprises a controllable pull-up resistor sub-circuit and a controllable pull-down resistor sub-circuit;

[0008] the control unit is configured to sequentially change the on and off states of the pull-down resistance sub-circuit and the controllable pull-up resistance sub-circuit of all the EPB switch input circuits and obtain the output level state of all the EPB switch input circuits in each state, to obtain the output level combination result of all the EPB switch input circuits in the same polling cycle.

[0009] The control unit is further configured to identify the current input state of the EPB switch and / or diagnose the fault of the EPB switch according to the output level combination result and a preset correspondence between the EPB switch input circuit output level and the EPB switch input state.

[0010] Optionally, the controllable pull-up resistance sub-circuit includes a controllable pull-up resistance, and the controllable pull-down resistance sub-circuit includes a controllable pull-down resistance; the first end of the controllable pull-up resistance and the first end of the controllable pull-down resistance of each of the EPB switch input circuits are coupled to form a common junction point, the first end of the common junction point is configured to be connected to the output port corresponding to the EPB switch input circuit, and the second end of the common junction point is coupled to the control unit; the second end of the controllable pull-up resistance and the second end of the controllable pull-down resistance are respectively coupled to the control unit.

[0011] The control unit is configured to sequentially control the controllable pull-down resistance of all the EPB switch input circuits to be on, the controllable pull-up resistance of one of the EPB switch input circuits to be on and the controllable pull-up resistances of the other EPB switch input circuits to be off, and obtain the output level state of all the EPB switch input circuits in each state, to obtain the output level combination result of all the EPB switch input circuits in the same polling cycle.

[0012] Optionally, the EPB switch input circuit has at least four paths, and the EPB switch input circuit configured to be connected to the first output port of the EPB switch further includes a fixed-value pull-up resistance for a wake-up function, and the first end of the fixed-value pull-up resistance is coupled to the common junction point.

[0013] Optionally, the EPB switch input circuit configured to be connected to the fourth output port of the EPB switch further includes a fixed-value pull-down resistance and a wake-up circuit, the first end of the fixed-value pull-down resistance is coupled to the common junction point, the first end of the wake-up circuit is coupled to the common junction point, and the second end of the wake-up circuit is configured to be coupled to a wake-up pin of a system base chip, and the system base chip is configured to supply power to the control unit.

[0014] Optionally, a ratio of the resistance of the controllable pull-up resistor to the resistance of the controllable pull-down resistor is less than 1 / 9; the resistance of the fixed pull-up resistor is equal to the resistance of the fixed pull-down resistor, and both are greater than 500 kΩ.

[0015] Optionally, each of the EPB switch input circuits further comprises a static current prevention sub-circuit; a first end of the static current prevention sub-circuit is coupled to a second end of the common junction, and a second end of the static current prevention sub-circuit is coupled to the control unit.

[0016] Optionally, the EPB switch input circuit output level-EPB switch input state preset correspondence comprises a first truth table of output levels of each of the EPB switch input circuits in a same polling cycle when the EPB switch is in a zero position state, a second truth table of output levels of each of the EPB switch input circuits in the same polling cycle when the EPB switch is in a tightening state, and a third truth table of output levels of each of the EPB switch input circuits in the same polling cycle when the EPB switch is in a releasing state.

[0017] The control unit is configured to identify a current input state of the EPB switch according to the output level combination result and the first truth table of output levels, the second truth table of output levels, and the third truth table of output levels, and start a next polling cycle to reacquire the output level combination result if the output level combination result obtained in one polling cycle does not find a corresponding output level truth table.

[0018] Optionally, the EPB switch input circuit output level-EPB switch input state preset correspondence further comprises a fourth truth table of output levels of each of the EPB switch input circuits in the same polling cycle when the EPB switch is in a short circuit state and / or a fifth truth table of output levels of each of the EPB switch input circuits in the same polling cycle when the EPB switch is in an open circuit state.

[0019] The control unit is further configured to diagnose a fault of the EPB switch according to the output level combination result and the fourth truth table of output levels and / or the fifth truth table of output levels.

[0020] To achieve the above-mentioned purpose, the application further provides an EPB controller, which comprises an EPB switch and any one of the above-mentioned EPB switch input devices.

[0021] To achieve the above-mentioned purpose, the application further provides an electronic parking control system, which comprises any one of the above-mentioned EPB switch input devices or the above-mentioned EPB controller.

[0022] In order to achieve the above object, the application further provides an acquisition method of EPB switch input state, which is used in the EPB switch input device, the EPB controller or the electronic parking control system, and comprises the following steps of:

[0023] sequentially changing the on and off states of the controllable pull-down resistor sub-circuit and the controllable pull-up resistor sub-circuit of all the EPB switch input circuits and acquiring the output level state of all the EPB switch input circuits in each state, so as to obtain the output level combination result of all the EPB switch input circuits in the same polling cycle;

[0024] according to the output level combination result and the preset correspondence between the EPB switch input circuit output level and the EPB switch input state, identifying the current input state of the EPB switch and / or diagnosing the fault of the EPB switch.

[0025] Compared with the prior art, the application provides an EPB switch input device, an EPB controller, an electronic parking control system and a method, which have the following advantages:

[0026] The EPB switch input device provided by the application comprises an EPB switch input circuit corresponding to each output port of the EPB switch, each EPB switch input circuit comprises a controllable pull-up resistor sub-circuit and a controllable pull-down resistor sub-circuit, so that the control unit can change the on and off states of the controllable pull-up resistor sub-circuit and the controllable pull-down resistor sub-circuit, and then acquire the connection state of the output port of the EPB switch, and then identify the intention of the driver inputting the EPB switch. Further, the control unit sequentially changes the on and off states of the controllable pull-down resistor sub-circuit and the controllable pull-up resistor sub-circuit of all the EPB switch input circuits and acquires the output level state of all the EPB switch input circuits in each state, so as to obtain the output level combination result of all the EPB switch input circuits in the same polling cycle. According to the output level combination result and the preset correspondence between the EPB switch input circuit output level and the EPB switch input state, the current input state of the EPB switch is identified and / or the fault of the EPB switch is diagnosed. Therefore, the EPB switch input device provided by the application can replace the chip with EPB switch input function which is bound to the motor control function, so that the EPB switch and the motor control device can be selected separately, thereby making the design of the motor controller more flexible, and further reducing the risk of insufficient production capacity caused by the shortage of chips with EPB switch input reading function. Further, the EPB switch input device provided by the application has clear logic, simple structure and is easy to implement.

[0027] Further, the EPB switch input device provided by the application is configured to connect the fourth output port of the EPB switch, and the EPB switch input circuit further comprises a constant value pull-down resistor and a wake-up circuit, the first end of the constant value pull-down resistor is coupled to the common contact point, the first end of the wake-up circuit is coupled to the common contact point, and the second end of the wake-up circuit is configured to be coupled to a wake-up pin of a system base chip, and the system base chip is configured to supply power to the control unit. Thus, the EPB switch state can be input to the control unit through the EPB switch input circuit, so that the driver can wake up the EPB controller by pulling the EPB switch when the EPB controller is in a sleep state.

[0028] The EPB controller, the electronic parking control system and the method provided by the application belong to the same inventive concept as the EPB switch input device provided by the application, and therefore, the EPB controller, the electronic parking control system and the method provided by the application have at least all the advantages of the EPB switch input device provided by the application. For the details of the beneficial effects of the EPB controller, the electronic parking control system and the method provided by the application, please refer to the related description of the beneficial effects of the EPB switch input device provided by the application, which will not be repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 A specific example structure diagram of an EPB switch in the related art;

[0030] Figure 2 A connection relationship diagram of the EPB switch in different states in the related art; Figure 1

[0031] Figure 3 A structure block diagram of the EPB switch input device provided by the first embodiment of the application;

[0032] Figure 4a A structure block diagram of the EPB switch input circuit for connecting the first output port of the EPB switch in the EPB switch input device shown in FIG. 2; Figure 3

[0033] A structure block diagram of the EPB switch input circuit for connecting the second output port of the EPB switch in the EPB switch input device shown in FIG. 3; Figure 4b Figure 3 A structure block diagram of the EPB switch input circuit for connecting the third output port of the EPB switch in the EPB switch input device shown in FIG. 4;

[0034] Figure 4c Figure 3 A structure block diagram of the EPB switch input circuit for connecting the third output port of the EPB switch in the EPB switch input device shown in FIG. 4;

[0035] Figure 4d A structure block diagram of the EPB switch input circuit for connecting the third output port of the EPB switch in the EPB switch input device shown in FIG. 4;​​​Figure 3 Structure block diagram of EPB switch input circuit for connecting fourth output port of EPB switch in the shown EPB switch input device;

[0036] Figure 5 Flow diagram of the acquisition method of EPB switch input state provided for the fourth embodiment of the present application;

[0037] In which, the reference signs are as follows:

[0038] First output port-EPB_SW1, second output port-EPB_SW2, third output port-EPB_SW3, fourth output port-EPB_SW4;

[0039] EPB switch-100;

[0040] EPB switch input circuit-210, 220, 230, 240, control unit-MCU;

[0041] Controllable pull-up resistor-211, 221, 231, 241, controllable pull-down resistor-212, 222, 232, 242, common connection point-213, 223, 233, 243;

[0042] Fixed value pull-up resistor-214, fixed value pull-down resistor-244;

[0043] Anti-static current sub-circuit-215, 225, 235, 245;

[0044] Wake-up circuit-246;

[0045] System base chip-SBC. DETAILED DESCRIPTION

[0046] The EPB switch input device, the EPB controller, the electronic parking control system and the method according to the present application will be further described in detail below with reference to the accompanying drawings. The advantages and features of the present application will be more apparent from the following description. It is to be noted that the drawings are in a very simplified form and are not drawn to precise scale, only for the purpose of facilitating the understanding of the embodiments of the present application. For the purpose of making the objects, features and advantages of the present application more apparent, reference should be made to the accompanying drawings. It is to be understood that the structures, proportions, sizes, etc. shown in the drawings are only for the purpose of illustrating the content disclosed in the present specification, for the understanding and reading of those skilled in the art, and are not intended to limit the present application. Any modification of the structure, change of the proportion relationship or adjustment of the size, as long as it is the same or similar to the effect and the purpose that can be achieved by the present application, should still fall within the scope of the technology disclosed by the present application. The specific design features of the present application disclosed herein include, for example, specific dimensions, directions, positions and shapes, which will be determined in part by the specific environment to be applied and used. In the embodiments described below, the same reference signs are sometimes used in different drawings to represent the same parts or parts with the same function, and the repeated description is omitted. In the present specification, similar reference signs and letters are used to represent similar items, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings. In addition, if the method described herein includes a series of steps, and the order of the steps presented herein is not necessarily the only order in which the steps can be performed, and some of the steps described herein can be omitted and / or some other steps not described herein can be added to the method.

[0047] It should be noted that the relational terms herein, such as first and second, and the like, are used solely to distinguish one from another entity or action without necessarily requiring or implying any actual relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises... a" does not, without more constraints, exclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element. The singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. The term "or" is generally employed in its sense including "and / or" unless the context clearly dictates otherwise. The term "and / or" means "and" or "or", and is used to indicate one or more, optionally including zero, of the listed items. The term "at least two" means "two or more", unless the context clearly dictates otherwise. The terms "first", "second", "third", etc. are used only to describe one entity or action from another, and cannot be understood as indicating or implying relative importance or implying a specific number of the technical features indicated.

[0048] It should be understood that when an element is referred to as being "connected to" or "coupled to" another element, it can be directly connected to the other element or intervening elements can be present. In contrast, when an element is referred to as being "directly connected to" or "directly coupled to" another element, there are no intervening elements present.

[0049] The core idea of the present application is to provide an EPB switch input device, an EPB controller, an electronic parking control system and a method, which can not only separate the selection of the EPB switch and the motor control device, making the design of the motor controller more flexible, but also reduce the risk of insufficient production capacity caused by the shortage of chips with EPB switch input reading function.

[0050] It should be noted that the EPB switch input device, the EPB controller, the electronic parking control system and the method provided by the present application can be applied to a vehicle. It should be understood that the term "vehicle" or "vehicle" or other similar terms used herein include general motor vehicles, such as passenger vehicles including sport utility vehicles (SUV), buses, trucks, various commercial vehicles, and hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, fuel cell vehicles and other alternative fuel vehicles (such as fuel obtained from resources other than oil).

[0051] To achieve the above idea, the first embodiment of the present application provides an EPB switch input device for an EPB switch. Specifically, please refer to Figure 3, Figure 3 The structure block diagram of the EPB switch input device provided for the first embodiment of the present application is shown in FIG. 1. From the structure block diagram, it can be seen that the EPB switch input device comprises an EPB switch input circuit and a control unit MCU. Figure 3 It can be seen that the EPB switch input device comprises an EPB switch input circuit and a control unit MCU. Figure 3 The number of the four-way EPB switch input circuits 210, 220, 230 and 240 is the same as the number of the output ports of the EPB switch 100; the first end of the EPB switch input circuit is configured to be connected with the corresponding output port, and the second end of the EPB switch input circuit is connected with the control unit MCU; the EPB switch input circuit comprises a controllable pull-up resistor sub-circuit (not shown in the figure, for example, see the controllable pull-up resistor 211 in the following Figure 4a , the controllable pull-up resistor 221 in the following Figure 4b , the controllable pull-up resistor 231 in the following Figure 4c or the controllable pull-up resistor 241 in the following Figure 4d ) and a controllable pull-down resistor sub-circuit (not shown in the figure, for example, see the controllable pull-down resistor 212 in the following Figure 4a , the controllable pull-down resistor 222 in the following Figure 4b , the controllable pull-down resistor 232 in the following Figure 4c or the controllable pull-down resistor 242 in the following Figure 4d ). Specifically, the control unit MCU is configured to change the on and off states of the controllable pull-down resistor sub-circuit and the controllable pull-up resistor sub-circuit of all the EPB switch input circuits in sequence and obtain the output level state of all the EPB switch input circuits in each state, so as to obtain the output level combination result of all the EPB switch input circuits in the same polling cycle. The control unit MCU is also used to identify the current input state of the EPB switch 100 and / or diagnose the fault of the EPB switch 100 according to the output level combination result and the preset correspondence between the EPB switch input circuit output level and the EPB switch 100 input state.

[0052] Thus, the EPB switch input device provided by the present application comprises an EPB switch input circuit corresponding to each output port of the EPB switch 100, each EPB switch input circuit comprises a controllable pull-up resistor sub-circuit and a controllable pull-down resistor sub-circuit, so that the control unit MCU changes the on and off states of the controllable pull-up resistor sub-circuit and the controllable pull-down resistor sub-circuit, and further obtains the connection state of the output port of the EPB switch 100, and further identifies the intention of the driver inputting the EPB switch 100. The foundation is laid; further, the control unit MCU changes the on and off states of the controllable pull-down resistor sub-circuit and the controllable pull-up resistor sub-circuit of all the EPB switch input circuits in turn, and obtains the output level state of each EPB switch input circuit in each state, obtains the output level combination result of all the EPB switch input circuits in the same polling cycle, and according to the output level combination result and the EPB switch input circuit output level-EPB switch 100 input state preset corresponding relationship, the current input state of the EPB switch 100 is identified and / or the fault of the EPB switch 100 is diagnosed. Thus, the EPB switch input device provided by the present application can replace the chip with EPB switch 100 input bound with motor control function, so that the EPB switch 100 and the motor control device can be selected separately, so that the design of the motor controller is more flexible, and then the risk of insufficient production capacity caused by shortage of chips with EPB switch 100 input reading function is reduced. Further, the EPB switch input device provided by the present application has clear logic, simple structure and is easy to implement.

[0053] The EPB switch input device provided by the present application has at least four EPB switch input circuits. In order to facilitate description and understanding, the EPB switch input device with four EPB switch input circuits is taken as an example for description. Figure 3 It should be noted that, as can be understood by those skilled in the art, Figure 3 The EPB switch input device with four EPB switch input circuits shown is only an exemplary description of the preferred embodiment, and is not a limitation of the present application. For example, the EPB switch input device provided by the present application is also applicable to an EPB switch 100 with a connection relationship of less than or equal to six output ports (PIN).

[0054] It is further needed to be explained that the specific implementation of the control unit MCU is not limited in the present application. Exemplarily, the control unit MCU can be, but is not limited to, a micro processing unit (MPU), other general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA) and other programmable logic device, discrete gate or transistor logic device, discrete hardware component. It is further needed to be explained that the specific implementation of the control unit MCU is not limited in the present application as can be understood by those skilled in the art. For example, in some exemplary embodiments, the control unit MCU can reuse the relevant hardware resources of the existing vehicle controller of the vehicle, such as reusing the EPB controller, i.e. upgrading the EPB controller, so that the EPB controller can be connected with the EPB switch input circuit and can control the controllable pull-up resistor sub-circuit and the controllable pull-down resistor sub-circuit of the EPB switch input circuit to have the functions of the control unit MCU of the EPB switch input device provided by the present application. Obviously, the vehicle controller provided by the present application can also reuse the hardware resources of other vehicle controllers except the EPB controller, which will not be listed one by one here. Further, in some other exemplary embodiments, the above-mentioned control unit MCU can also have independent hardware resources such as memory and processor, and is not integrated with any existing vehicle controller of the vehicle. Further, the specific implementation of the EPB switch input circuit of the EPB switch input device is not limited in the present application, such as in some embodiments, the EPB switch input circuit of the EPB switch input device provided by the present application can be integrated into a chip, and in some other embodiments, the EPB switch input circuit of the EPB switch input device can also exist in the form of discrete devices.

[0055] In some exemplary embodiments, please refer to Figure 4a 、 Figure 4b 、 Figure 4c and Figure 4d , wherein, Figure 4a is the structural block diagram of the EPB switch input circuit 210 for connecting the first output port EPB_SW1 of the EPB switch 100 in the EPB switch input device shown in Figure 3 . Figure 4b is the structural block diagram of the EPB switch input circuit 220 for connecting the second output port EPB_SW2 of the EPB switch 100 in the EPB switch input device shown in Figure 3 .Figure 4c For Figure 3 The structural block diagram of the EPB switch input circuit 230 for connecting the third output port EPB_SW3 of the EPB switch 100 in the EPB switch input device shown in Figure 4d For Figure 3 The structural block diagram of the EPB switch input circuit 240 for connecting the fourth output port EPB_SW4 of the EPB switch 100 in the EPB switch input device shown in. From Figure 4a 、 Figure 4b 、 Figure 4c And Figure 4d It can be seen that the controllable pull-up resistor sub-circuit includes a controllable pull-up resistor (exemplarily, the controllable pull-up resistor 211 of the EPB switch input circuit 210 shown in Figure 4a , the controllable pull-up resistor 221 of the EPB switch input circuit 220 shown in Figure 4b , the controllable pull-up resistor 231 of the EPB switch input circuit 230 shown in Figure 4c , and the controllable pull-up resistor 241 of the EPB switch input circuit 240 shown in Figure 4d ), the controllable pull-down resistor sub-circuit includes a controllable pull-down resistor (exemplarily, the controllable pull-down resistor 212 of the EPB switch input circuit 210 shown in Figure 4a , the controllable pull-down resistor 222 of the EPB switch input circuit 220 shown in Figure 4b , the controllable pull-down resistor 232 of the EPB switch input circuit 230 shown in Figure 4c , and the controllable pull-down resistor 242 of the EPB switch input circuit 240 shown in Figure 4d ); the first end of the controllable pull-up resistor of each of the EPB switch input circuits is coupled with the first end of the controllable pull-down resistor to form a common junction point (exemplarily, the common junction point 213 of the EPB switch input circuit 210 shown in Figure 4a , the common junction point 223 of the EPB switch input circuit 220 shown in Figure 4b , the common junction point 233 of the EPB switch input circuit 230 shown in Figure 4c , and the common junction point 243 of the EPB switch input circuit 240 shown in Figure 4d ), and the first end of the common junction point is configured to be connected with the output port corresponding to the EPB switch input circuit (exemplarily, the first end of the common junction point 213 of the EPB switch input circuit 210 is coupled with the first output port EPB_SW1 of the EPB switch 100 shown in Figure 4a , the first end of the common junction point 223 of the EPB switch input circuit 220 is coupled with the second output port EPB_SW2 of the EPB switch 100 shown in Figure 4b , and the first end of the common junction point 233 of the EPB switch input circuit 230 is coupled with the third output port EPB_SW3 of the EPB switch 100 shown in Figure 4cThe first end of the common connection point 233 of the EPB switch input circuit 230 is coupled with the third output port EPB_SW3 of the EPB switch 100, and the second end of the common connection point is coupled with the control unit MCU; the second end of the controllable pull-up resistor and the second end of the controllable pull-down resistor are respectively coupled with the control unit MCU. The control unit MCU is configured to control the controllable pull-down resistor of all the EPB switch input circuits in turn, control the controllable pull-up resistor of one of the EPB switch input circuits and turn off the controllable pull-up resistors of the other EPB switch input circuits, and obtain the output level state of all the EPB switch input circuits in each state, so as to obtain the output level combination result of all the EPB switch input circuits in the same polling cycle. Figure 4d The first end of the common connection point 233 of the EPB switch input circuit 230 is coupled with the third output port EPB_SW3 of the EPB switch 100, and the second end of the common connection point is coupled with the control unit MCU; the second end of the controllable pull-up resistor and the second end of the controllable pull-down resistor are respectively coupled with the control unit MCU. The control unit MCU is configured to control the controllable pull-down resistor of all the EPB switch input circuits in turn, control the controllable pull-up resistor of one of the EPB switch input circuits and turn off the controllable pull-up resistors of the other EPB switch input circuits, and obtain the output level state of all the EPB switch input circuits in each state, so as to obtain the output level combination result of all the EPB switch input circuits in the same polling cycle.

[0056] Therefore, the EPB switch input device provided by the application has the controllable pull-up resistor sub-circuit adopting the controllable pull-up resistor and the controllable pull-down resistor sub-circuit adopting the controllable pull-down resistor, which is convenient for the control of the control unit MCU, and the controllable pull-up resistor and the controllable pull-down resistor are low in price and simple in circuit structure and easy to implement. It should be noted that, as can be understood by those skilled in the art, the controllable pull-up resistor sub-circuit adopting the controllable pull-up resistor and the controllable pull-down resistor sub-circuit adopting the controllable pull-down resistor are only exemplary descriptions of preferred embodiments, and are not limitations of the application. In other embodiments, the controllable pull-up resistor sub-circuit and the controllable pull-down resistor sub-circuit can be realized by other ways except the controllable pull-up resistor and the controllable pull-down resistor. For example, a circuit composed of a fixed resistor and a controllable switch can be used. Here, no further examples are given.

[0057] Preferably, in some exemplary embodiments, the EPB switch input circuit output level-EPB switch 100 input state preset corresponding relationship includes a first truth table of output level of each of the EPB switch input circuit in the same polling cycle when the EPB switch 100 is in the zero position state, a second truth table of output level of each of the EPB switch input circuit in the same polling cycle when the EPB switch 100 is in the tightening state, and a third truth table of output level of each of the EPB switch input circuit in the same polling cycle when the EPB switch 100 is in the release state. The control unit MCU is configured to identify the current input state of the EPB switch 100 according to the output level combination result and the first truth table of output level, the second truth table of output level and the third truth table of output level, and if the output level combination result obtained in one polling cycle does not find the corresponding output level truth table, start the next polling cycle to reacquire the output level combination result.

[0058] Therefore, the EPB switch input device provided by the application can identify whether the EPB switch 100 is in the zero position state, the tightening state or the release state by polling the corresponding truth table of each EPB switch input circuit when the EPB switch 100 is in different states, so that the EPB switch input device provided by the application can replace the chip with EPB switch 100 input function bound to the motor control function, and the EPB switch 100 and the motor control device can be selected separately, so that the design of the motor controller is more flexible, and the risk of insufficient production capacity caused by shortage of chips with EPB switch 100 input reading function is reduced.

[0059] Exemplarily, please refer to Table 1, Table 2 and Table 3, wherein Table 1 is a first truth table of output level of each of the EPB switch input circuit in the same polling cycle when the EPB switch 100 is in the zero position state, Table 2 is a second truth table of output level of each of the EPB switch input circuit in the same polling cycle when the EPB switch 100 is in the tightening state, and Table 3 is a third truth table of output level of each of the EPB switch input circuit in the same polling cycle when the EPB switch 100 is in the release state.

[0060] Table 1

[0061]

[0062] Table 2

[0063]

[0064] Table 3

[0065]

[0066] Specifically, when all four output ports of EPB switch 100 are in a weak pull-down state by default, if a strong pull-up is applied to one of the output ports, according to... Figure 4a As shown in the connection diagram, the input port itself and any input ports connected to the output port will be in a high-level state, while any output ports not connected will be in a low-level state. Based on this principle, when the EPB controller enters normal operation, the controllable pull-down resistors 212, 222, 232, and 242 of the four EPB switch input circuits 210, 220, 230, and 240 will be turned on. By polling, one of the controllable pull-up resistors 211, 221, 231, and 241 of the four EPB switch input circuits 210, 220, 230, and 240 will be turned on sequentially. The control unit MCU reads the high and low level states of the four EPB switch input circuits, thereby identifying the current input state of the EPB switch 100.

[0067] Exemplarily, in one embodiment, the controllable pull-down resistors 212, 222, 232 and 242 of the four EPB switch input circuits are first turned on simultaneously, then the controllable pull-up resistor 211 of the first EPB switch input circuit 210 is turned on (pulled up), the controllable pull-up resistors 221, 231 and 241 of the second, third and fourth EPB switch input circuits 220, 230 and 240 are turned off, so that the output level states of the four EPB switch input circuits are in turn: high-low-high-low; then the controllable pull-up resistor 221 of the second EPB switch input circuit 220 is turned on (pulled up), the controllable pull-up resistors 211, 231 and 241 of the first, third and fourth EPB switch input circuits 210, 230 and 240 are turned off, so that the output level states of the four EPB switch input circuits are in turn: low-high-low-high; then the controllable pull-up resistor 231 of the third EPB switch input circuit 230 is turned on (pulled up), the controllable pull-up resistors 211, 221 and 241 of the first, second and fourth EPB switch input circuits 210, 220 and 240 are turned off, so that the output level states of the four EPB switch input circuits are in turn: high-low-high-low; finally, the controllable pull-up resistor 241 of the fourth EPB switch input circuit 240 is turned on (pulled up), the controllable pull-up resistors 211, 221 and 231 of the first, second and third EPB switch input circuits 210, 220 and 230 are turned off, so that the output level states of the four EPB switch input circuits are in turn: low-high-low-high. Thus, the continuous four polling pull-up on states from the turning on (pulling up) of the controllable pull-up resistor 211 of the first EPB switch input circuit 210 to the turning on (pulling up) of the controllable pull-up resistor 241 of the fourth EPB switch input circuit 240 obtain a complete polling period. At this time, the output level combination result in the polling period is: high-low-high-low, low-high-low-high, high-low-high-low, low-high-low-high. By comparing Table 1, Table 2 and Table 3, it can be concluded that the output level combination result is exactly the same as Table 1, so it can be judged that the EPB switch 100 is currently in the zero position state. If the output level combination result read by the control unit MCU in the same polling period does not have a corresponding truth table, the control unit MCU considers that the EPB switch 100 switches in this polling period, and waits for the output level combination result of the next polling period.

[0068] Further, in a specific example, according to the current hardware circuit design, the time from the EPB switch input circuit outputting the opening pull-up signal from the control unit MCU to the EPB switch input circuit reading the output level state of the four EPB switch input circuits is 2.5 ms, which can ensure that the level state of the EPB switch input circuit can reach a stable state after the pull-up controllable resistance is switched. Therefore, the time required for a whole polling cycle is 10 ms. In the most extreme case of the EPB switch 100 changing, the four EPB switch input circuits cannot reach a stable state before the control unit MCU reads the state within 2.5 ms after the pull-up of the first EPB switch input circuit 110 has been opened, so this round of polling is invalid, and the next polling cycle needs to be waited for. As can be seen, the EPB switch input device provided by the application can ensure that the longest time from the EPB switch 100 changing to the control unit MCU reading the corresponding state is not more than 20 ms, and can well respond to the operation of the driver on the EPB switch 100.

[0069] Further, in some exemplary embodiments, the EPB switch input circuit output level-EPB switch 100 input state preset correspondence further includes a fourth truth table of the output level of each of the EPB switch input circuits in the same polling cycle when the EPB switch 100 is in a short-circuit state and / or a fifth truth table of the output level of each of the EPB switch input circuits in the same polling cycle when the EPB switch 100 is in an open-circuit state. The control unit MCU is further configured to diagnose the fault of the EPB switch 100 according to the output level combination result and the fourth truth table of the output level and / or the fifth truth table of the output level.

[0070] Therefore, the EPB switch input device provided by the application, the EPB switch input circuit output level-EPB switch 100 input state preset correspondence further includes a fourth truth table of the output level when the EPB switch 100 is in a short-circuit state and a fifth truth table of the output level when the EPB switch 100 is in an open-circuit state, thereby laying a foundation for the control unit MCU to diagnose whether the EPB switch 100 is in a fault state according to the output level combination result, so that the EPB switch input device provided by the application has the function of diagnosing the fault of the EPB switch 100.

[0071] It should be noted that, as can be understood by those skilled in the art, the output level first truth table, the output level second truth table, the output level third truth table, the output level fourth truth table and the output level fifth truth table of the preset correspondence relationship between the output level of the EPB switch input circuit and the input state of the EPB switch 100 are only exemplary and are not limited by the present application. The present application does not make too many limitations on the specific content of the preset correspondence relationship between the output level of the EPB switch input circuit and the input state of the EPB switch 100.

[0072] Preferably, in some exemplary embodiments, please continue to refer to Figure 4b From Figure 4c It can be seen that the EPB switch input circuit configured to connect the first output port EPB_SW1 of the EPB switch 100 further comprises a fixed value pull-up resistor 214 for wake-up function, and a first end of the fixed value pull-up resistor 214 is coupled to the common connection point 213. Thus, the EPB switch input device provided by the present application can pull up the output of the EPB switch 100 to VBAT (battery power supply) normal power supply through the fixed value pull-up resistor 214 for wake-up function, thereby ensuring the power supply requirement of the control unit MCU in the sleep state.

[0073] Preferably, in some exemplary embodiments, please refer to Figure 4d From Figure 4a It can be seen that the EPB switch input circuit configured to connect the fourth output port EPB_SW4 of the EPB switch 100 further comprises a fixed value pull-down resistor 244 and a wake-up circuit 246, a first end of the fixed value pull-down resistor 244 is coupled to the common connection point 243, a first end of the wake-up circuit 246 is coupled to the common connection point 243, and a second end of the wake-up circuit 246 is configured to be coupled to a wake-up pin of a system basis chip SBC (System Basis Chip) for supplying power to the control unit MCU.

[0074] Specifically, the EPB switch input device provided by the present application, the first route EPB switch input circuit 210 has a fixed value pull-up resistor 214 that is pulled up to VBAT normal power, the fourth route EPB switch input circuit 240 has a wake-up circuit 246 connected to a wake-up PIN (pin) of a system basis chip SBC and a fixed value pull-down resistor 244. According to Figure 4bThe connection relationship is shown that when the EPB switch 100 is in the middle position, the output of the first path (the first path EPB switch input circuit 210 connects the first output port EPB_SW1 of the EPB switch 100) and the output of the fourth path (the fourth path EPB switch input circuit 240 connects the fourth output port EPB_SW4 of the EPB switch 100) have no connection relationship, while when the EPB switch 100 is in the release or tension state, the output of the first path and the output of the fourth path have a connection relationship. According to this principle, when the driver actuates the EPB switch 100, the level of the fourth path EPB switch input circuit 240 will be converted from the low level provided by the fixed value pull-down resistor 244 to the voltage formed by the voltage division of the fixed value pull-up resistor 214 and the fixed value pull-down resistor 244, which can make the wake-up circuit 246 output a high level to the system basic chip SBC wake-up PIN, so as to wake up the system basic chip SBC power supply and the entire EPB controller.

[0075] Preferably, in some exemplary embodiments, the ratio of the resistance value of the controllable pull-up resistor 211, 221, 231, 241 to the resistance value of the controllable pull-down resistor 212, 222, 232, 242 is less than 1 / 9; the resistance value of the fixed value pull-up resistor 214 and the fixed value pull-down resistor 244 is equal, and both are greater than 500k ohms. Thus, by setting the ratio of the resistance value of the controllable pull-up resistor 211, 221, 231, 241 to the resistance value of the controllable pull-down resistor 212, 222, 232, 242 to be less than 1 / 9, it can be ensured that when the multiple EPB switch input circuits 210, 220, 230 and 240 are connected, the state of the EPB switch input device can be effectively identified. By setting the resistance value of the fixed value pull-up resistor 214 and the fixed value pull-down resistor 244 to be equal and greater than 500k ohms, it can not only ensure that after the EPB switch 100 input meets the wake-up condition (i.e. after voltage division by the fixed value pull-up resistor 214 and the fixed value pull-down resistor 244), the voltage can reach the voltage determined by the wake-up circuit 246 as an effective wake-up source, but also can ensure that when the EPB switch 100 does not input the wake-up source signal, the resistance is large enough to effectively prevent excessive leakage current from consuming the battery power when parking.

[0076] Exemplarily, as preferred, by setting the resistance value of a single controllable pull-up resistor: the resistance value of a single controllable pull-down resistor to be less than 1 / 9, such as Figure 4cAs shown, when the EPB switch input circuits 210, 220, 230 and 240 are connected to the four EPB switch input circuits, (such as the maximum of four controllable pull-down resistors 212, 222, 232, 242 in parallel with a controllable pull-up resistor (such as the controllable pull-up resistor 211 of the EPB switch input circuit 210) to divide the voltage, which can ensure that the corresponding EPB switch input circuit (such as the EPB switch input circuit 210) is recognized as high level. Preferably, by setting the resistance value of the fixed pull-up resistor 214 and the resistance value of the single fixed pull-down resistor 244 to be equal, such as both resistance values being greater than 500k ohms, the fixed pull-down resistor 244 providing the wake-up function can be ensured to reach the voltage that the wake-up circuit determines as an effective wake-up source after the EPB switch 100 inputs meet the wake-up condition (that is, after the voltage is divided by the two fixed resistors), and the resistance is large enough when the EPB switch 100 does not input the wake-up source signal, effectively preventing excessive leakage current from consuming the battery power when parking. It should be noted that those skilled in the art can understand that the resistance value of the pull-up resistor: the resistance value of the single controllable pull-down resistor is less than 1 / 9, and the resistance value of the fixed pull-up resistor and the single fixed pull-down resistor 244 are both greater than 500K ohms in this article are only exemplary descriptions of preferred embodiments, and are not limitations of the present application. In the application of the present application, the resistance value of the controllable pull-up resistor, the resistance value of the controllable pull-down resistor, the resistance value of the fixed pull-down resistor, and the resistance value of the fixed pull-up resistor should be reasonably set according to actual needs.

[0077] Please continue to see Figure 4d 、 Figure 5 、 Figure 5 and Figure 5 From ​ 、 ​ 、 ​ and ​ It can be seen that in some of the exemplary embodiments, each of the EPB switch input circuits further comprises a static current prevention sub-circuit (exemplarily, such as the static current prevention sub-circuit 215 of the EPB switch input circuit 210 as shown in ​ , the static current prevention sub-circuit 225 of the EPB switch input circuit 220 as shown in ​ , the static current prevention sub-circuit 235 of the EPB switch input circuit 230 as shown in ​ , and the static current prevention sub-circuit 245 of the EPB switch input circuit 240 as shown in ​ ); the first end of the static current prevention sub-circuit is coupled to the second end of the common connection point (exemplarily, such as the first end of the static current prevention sub-circuit 215 being coupled to the second end of the common connection point 213 as shown in ​ , the first end of the static current prevention sub-circuit 225 being coupled to the second end of the common connection point 223 as shown in ​ , the first end of the static current prevention sub-circuit 235 being coupled to the second end of the common connection point 233 as shown in ​The first end of the anti-static current sub-circuit 235 is coupled to the second end of the common connection point 233, and the second end of the anti-static current sub-circuit is coupled to the control unit MCU. ​ The first end of the anti-static current sub-circuit 245 is coupled to the second end of the common connection point 243, and the second end of the anti-static current sub-circuit is coupled to the control unit MCU. Since each EPB switch input circuit has an anti-static current sub-circuit, the anti-static current sub-circuit will disconnect the input circuit of the control unit MCU after the EPB controller is powered off, and the anti-static current sub-circuit will be closed again when the EPB controller is normally powered on. The EPB switch input circuit can avoid discharging the control unit MCU, thereby protecting the control unit MCU well and improving the safety and reliability of the EPB switch input device.

[0078] It should be noted that, as can be understood by those skilled in the art, the present application does not make too many limitations on the specific implementation of the anti-static current sub-circuit. For more detailed content of the anti-static current sub-circuit, please refer to the relevant technical adaptive understanding known to those skilled in the art, which will not be described here.

[0079] Based on the same inventive concept, the second embodiment of the present application provides an EPB controller. The EPB controller provided in the embodiment includes an EPB switch and the EPB switch input device provided in any of the embodiments of the first embodiment. Since the EPB controller provided by the present application belongs to the same inventive concept as the EPB switch input device provided by the present application, the EPB controller provided by the present application at least has all the advantages of the EPB switch input device provided by the present application. For detailed content of the beneficial effects of the EPB controller provided by the present application, please refer to the related description of the beneficial effects of the EPB switch input device provided by the present application in the above, which will not be described here. Further, since the basic principle of the EPB controller provided by the present application is the same as that of the EPB switch input device provided by the present application, for more detailed content of the EPB controller provided by the present application, please refer to the related description of the EPB switch input device provided by the present application in the above, which will not be described here.

[0080] Based on the same inventive concept, the third embodiment of the present application provides an electronic parking control system. The electronic parking control system provided in the embodiment includes the EPB switch input device provided in any of the embodiments of the first embodiment or the EPB controller provided in the second embodiment.

[0081] Based on the same inventive concept, the fourth embodiment of the present application provides an EPB switch input state acquisition method. It is used for the switch input device, the EPB controller or the electronic parking control system provided by the present application. For details, please refer to ​ , ​The embodiment provides a flowchart of an acquisition method of an EPB switch input state. ​ It can be seen that the acquisition method comprises:

[0082] S100: sequentially changing on and off states of the controllable pull-down resistor sub-circuit and the controllable pull-up resistor sub-circuit of all the EPB switch input circuits and acquiring output level states of all the EPB switch input circuits in each state, to obtain output level combination results of the output level states of all the EPB switch input circuits in a same polling period;

[0083] S200: identifying the current input state of the EPB switch and / or diagnosing a fault of the EPB switch according to the output level combination results and a preset correspondence relationship between an EPB switch input circuit output level and an EPB switch input state.

[0084] Compared with the prior art, the EPB switch input device, the EPB controller, the electronic parking control system and the method have the following advantages:

[0085] The EPB switch input device provided by the application comprises an EPB switch input circuit corresponding to an output port of an EPB switch, each EPB switch input circuit comprises a controllable pull-down resistor sub-circuit and a controllable pull-up resistor sub-circuit, thereby laying a foundation for a control unit to change on and off states of the controllable pull-down resistor sub-circuit and the controllable pull-up resistor sub-circuit, to further acquire a connection state of the output port of the EPB switch, and to further identify an intention of a driver inputting the EPB switch. Further, the control unit sequentially changes on and off states of the controllable pull-down resistor sub-circuit and the controllable pull-up resistor sub-circuit of all the EPB switch input circuits and acquires output level states of all the EPB switch input circuits in each state, to obtain output level combination results of the output level states of all the EPB switch input circuits in a same polling period. According to the output level combination results and a preset correspondence relationship between an EPB switch input circuit output level and an EPB switch input state, the current input state of the EPB switch is identified and / or a fault of the EPB switch is diagnosed. Therefore, the EPB switch input device provided by the application can replace a chip with an EPB switch input function that is bound to a motor control function, so that the EPB switch and the motor control device can be selected separately, thereby making the design of the motor controller more flexible, and further reducing the risk of insufficient production capacity caused by a shortage of the chip with the EPB switch input reading function. Further, the EPB switch input device provided by the application has clear logic, a simple structure and is easy to implement.

[0086] Further, the EPB switch input device provided by the application is configured to connect the fourth output port of the EPB switch, and the EPB switch input circuit further comprises a constant value pull-down resistor and a wake-up circuit, the first end of the constant value pull-down resistor is coupled to the common contact point, the first end of the wake-up circuit is coupled to the common contact point, and the second end of the wake-up circuit is configured to be coupled to a wake-up pin of a system base chip, and the system base chip is configured to supply power to the control unit. Thus, the EPB switch state can be input to the control unit through the EPB switch input circuit, so that the driver can wake up the EPB controller by pulling the EPB switch when the EPB controller is in a sleep state.

[0087] Since the EPB controller, the electronic parking control system and the method provided by the application belong to the same inventive concept as the EPB switch input device provided by the application, the EPB controller, the electronic parking control system and the method provided by the application at least have all the advantages of the EPB switch input device provided by the application. For the details of the advantages of the EPB controller, the electronic parking control system and the method provided by the application, please refer to the above description of the advantages of the EPB switch input device provided by the application. Here, it will not be repeated.

[0088] It should be noted that the apparatus and method disclosed in the embodiments herein can also be implemented in other ways. The apparatus embodiments described above are only schematic. For example, the flowcharts and block diagrams in the drawings show possible implementation architectures, functions and operations of the apparatus, method and computer program product according to the embodiments herein. In this regard, each block in the flowcharts and block diagrams can represent a module, a program segment or a part of code, which contains one or more executable instructions for implementing the specified logical functions. It should also be noted that each block in the flowcharts and / or block diagrams, and the combination of blocks in the flowcharts and / or block diagrams, can be implemented by a dedicated hardware-based system, or can be implemented by a combination of dedicated hardware and computer instructions.

[0089] In addition, each functional module in the embodiments herein can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0090] The above description is only a description of a preferred embodiment of the EPB switch input device, the EPB controller, the electronic parking control system and the method provided by the present application, and does not limit the scope of the present application. Any modification or change made by a person skilled in the art according to the above disclosure is within the scope of the present application. Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations are within the scope of the present application and equivalent technology thereof, the present application is intended to include these modifications and variations.

Claims

1. An EPB switch input device for an EPB switch, characterized in that, The EPB switch input device includes an EPB switch input circuit and a control unit. The number of EPB switch input circuits is the same as the number of output ports of the EPB switch. A first terminal of each EPB switch input circuit is configured to connect to its corresponding output port, and a second terminal of each EPB switch input circuit is connected to the control unit. Each EPB switch input circuit includes a controllable pull-up resistor sub-circuit and a controllable pull-down resistor sub-circuit. The controllable pull-up resistor sub-circuit includes a controllable pull-up resistor, and the controllable pull-down resistor sub-circuit includes a controllable pull-down resistor. The first terminal of the controllable pull-up resistor and the first terminal of the controllable pull-down resistor in each EPB switch input circuit are coupled to form a common connection point. The first terminal of the common connection point is configured to connect to the output port corresponding to that EPB switch input circuit, and the second terminal of the common connection point is coupled to the control unit. The second terminals of both the controllable pull-up resistor and the controllable pull-down resistor are respectively coupled to the control unit. The control unit is configured to sequentially change the on and off states of the controllable pull-down resistor circuit and the controllable pull-up resistor circuit of all the EPB switch input circuits and obtain the output level state of all the EPB switch input circuits in each state, so as to obtain the output level combination result of the output level states of all the EPB switch input circuits in the same polling cycle. The control unit is also used to identify the current input state of the EPB switch and / or diagnose the fault of the EPB switch based on the output level combination result and the preset correspondence between the output level of the EPB switch input circuit and the input state of the EPB switch.

2. The EPB switch input device according to claim 1, characterized in that, The control unit is configured to sequentially control the controllable pull-down resistors of all EPB switch input circuits to be turned on, the controllable pull-up resistors of one EPB switch input circuit to be turned on, and the controllable pull-up resistors of the other circuits to be turned off, and to acquire the output level state of all EPB switch input circuits in each state, so as to obtain the output level combination result of the output level states of all EPB switch input circuits in the same polling cycle.

3. The EPB switch input device according to claim 2, characterized in that, The EPB switch input circuit has at least four channels. The EPB switch input circuit configured to connect to the first output port of the EPB switch also includes a fixed pull-up resistor for wake-up function, the first end of which is coupled to the common contact.

4. The EPB switch input device according to claim 3, characterized in that, The EPB switch input circuit, configured to connect to the fourth output port of the EPB switch, further includes a fixed pull-down resistor and a wake-up circuit. The first end of the fixed pull-down resistor is coupled to the common contact point, the first end of the wake-up circuit is coupled to the common contact point, and the second end of the wake-up circuit is configured to be coupled to the wake-up pin of the system base chip, which is used to power the control unit.

5. The EPB switch input device according to claim 4, characterized in that, The ratio of the resistance value of the controllable pull-up resistor to the resistance value of the controllable pull-down resistor is less than 1 / 9; the resistance values ​​of the fixed pull-up resistor and the fixed pull-down resistor are equal and both are greater than 500k ohms.

6. The EPB switch input device according to claim 2, characterized in that, Each of the EPB switch input circuits further includes a static current protection sub-circuit; the first terminal of the static current protection sub-circuit is coupled to the second terminal of the common contact, and the second terminal of the static current protection sub-circuit is coupled to the control unit.

7. The EPB switch input device according to any one of claims 1 to 6, characterized in that, The preset correspondence between the output level of the EPB switch input circuit and the input state of the EPB switch includes a first truth table of the output level of each EPB switch input circuit in the same polling cycle when the EPB switch is in the zero position, a second truth table of the output level of each EPB switch input circuit in the same polling cycle when the EPB switch is in the tightened state, and a third truth table of the output level of each EPB switch input circuit in the same polling cycle when the EPB switch is in the released state. The control unit is configured to identify the current input state of the EPB switch based on the output level combination result and the first truth table, the second truth table and the third truth table of the output level; If no corresponding output level truth table is found for the output level combination result obtained within a polling cycle, the next polling cycle is started to re-obtain the output level combination result.

8. The EPB switch input device according to claim 7, characterized in that, The preset correspondence between the output level of the EPB switch input circuit and the input state of the EPB switch also includes a fourth truth table of the output level of each EPB switch input circuit in the same polling cycle when the EPB switch is in a short-circuit state and / or a fifth truth table of the output level of each EPB switch input circuit in the same polling cycle when the EPB switch is in an open-circuit state. The control unit is also configured to diagnose faults in the EPB switch based on the output level combination result and the fourth truth table and / or the fifth truth table of the output level.

9. An EPB controller, characterized in that, Includes an EPB switch and an EPB switch input device as described in any one of claims 1 to 8.

10. An electronic parking control system, characterized in that, Includes the EPB switch input device as described in any one of claims 1 to 8 or the EPB controller as described in claim 9.

11. A method for obtaining the input state of an EPB switch, characterized in that, For use with the EPB switch input device as described in any one of claims 1 to 8, the EPB controller as described in claim 9, or the electronic parking control system as described in claim 10, the acquisition method includes: The on and off states of the controllable pull-down resistor circuit and the controllable pull-up resistor circuit of all the EPB switch input circuits are changed sequentially, and the output level state of all the EPB switch input circuits in each state is obtained to obtain the output level combination result of all the EPB switch input circuits in the same polling cycle. Based on the output level combination result and the preset correspondence between the output level of the EPB switch input circuit and the input state of the EPB switch, the current input state of the EPB switch can be identified and / or the fault of the EPB switch can be diagnosed.

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