Actuator comprising DC motor and control method of the same

Abstract

An actuator of a vehicle is disclosed, and the actuator according to one embodiment of the present invention comprises: a DC motor that is driven by the application of current to change the gear ratio; a position sensor for detecting the position of the DC motor; and a control unit for controlling the DC motor, wherein the control unit includes a bidirectional switch circuit for controlling the flow of current to the DC motor, and is configured such that when a voltage from a position sensor power supply is applied to the position sensor, the bidirectional switch circuit operates to drive the DC motor.

Description

Technology Field

[0001] The present invention relates to an actuator for a vehicle including a DC (Direct Current) motor and a method for controlling the same. Specifically, the present invention relates to an actuator including a DC motor and a method for controlling the same, wherein the security performance is enhanced by providing a security circuit on the power line of the DC motor. Background Technology

[0002] In automatic transmissions for vehicles, BLDC (Brushless Direct Current) motors are often used as motors to change gears, but these BLDC motors have disadvantages such as being expensive, heavy, and having a complex drive mechanism structure.

[0003] In contrast, using a DC motor (brush type) has the advantages of being inexpensive and having a simple structure; however, since it can be driven by connecting power to a connector, it has the disadvantage of being easy to operate from the outside, which may pose security issues such as theft prevention.

[0004] Therefore, there is a need for a transmission actuator that can improve security performance for vehicle theft prevention while using a DC motor, which is inexpensive and has a simple structure. The problem to be solved

[0005] The present invention aims to solve the problems of the aforementioned prior art by providing an actuator including a DC motor that reduces manufacturing costs, has a simple structure, and is equipped with a security function, as well as a control method thereof.

[0006] In addition, the present invention aims to provide an actuator including a DC motor and a control method thereof, which further enhances security performance by operating a bidirectional switch circuit only when a predetermined data signal is received using communication with a vehicle processor.

[0007] However, the technical problems that the embodiments of the present invention aim to solve are not limited to the technical problems described above, and other technical problems may exist. means of solving the problem

[0008] As a technical means for achieving the above-mentioned technical problem, an actuator of a vehicle according to one embodiment of the present invention comprises: a DC motor that is driven by the application of current to change the gear ratio; a position sensor for detecting the position of the DC motor; and a control unit for controlling the DC motor, wherein the control unit includes a bidirectional switch circuit for controlling the flow of current to the DC motor, and is configured such that when a voltage from a position sensor power supply is applied to the position sensor, the bidirectional switch circuit operates to drive the DC motor.

[0009] Meanwhile, an actuator of a vehicle according to another embodiment of the present invention comprises: a DC motor that is driven by the application of current to change the gear ratio; a position sensor for detecting the position of the DC motor; and a control unit for controlling the DC motor, wherein the control unit includes a bidirectional switch circuit for controlling the flow of current to the DC motor and a microprocessor connected to the bidirectional switch circuit, and is configured such that when the microprocessor receives a predetermined data signal through communication with the vehicle's processor, the bidirectional switch circuit operates to drive the DC motor.

[0010] In addition, the bidirectional switch circuit may be configured to operate to drive the DC motor when a voltage from the position sensor power supply is applied to the position sensor and the microprocessor receives the predetermined data signal.

[0011] In addition, the microprocessor can recognize the received data signal in synchronization with the output signal of the position sensor, determine whether it is the predetermined data signal, and when it transmits a reception acknowledgment signal, it can operate the bidirectional switch circuit.

[0012] In addition, the microprocessor may request the retransmission of the data signal a predetermined number of times if the received data signal is not the predetermined data signal, and control the bidirectional switch circuit so that it does not operate if the reception of the data signal exceeds the predetermined number of times.

[0013] Meanwhile, a method for controlling an actuator of a vehicle according to an embodiment of the present invention is characterized by comprising: a step of receiving a data signal from a processor of the vehicle; a step of determining whether the received data signal is a predetermined data signal; a step of operating a bidirectional switch circuit for controlling the flow of current to a DC motor when the received data signal is a predetermined data signal; and a step of driving the DC motor.

[0014] In addition, the step of determining whether the received data signal is a predetermined data signal may recognize the received data signal in synchronization with the output signal of a position sensor for detecting the position of the DC motor, and transmit a reception acknowledgment signal if it is determined to be the predetermined data signal.

[0015] In addition, in the step of determining whether it is a predetermined data signal, if it is determined that it is not a predetermined data signal, a request to resend the data signal is transmitted to the processor of the vehicle, and if the data signal is received more than a predetermined number of times due to the repetition of the resend request, the bidirectional switch circuit can be controlled so that it does not operate.

[0016] The means for solving the problem described above are merely exemplary and should not be interpreted as intended to limit the present invention. In addition to the exemplary embodiments described above, additional embodiments may exist in the drawings and the detailed description of the invention. Effects of the invention

[0017] According to the means for solving the problem of the present invention described above, in an actuator for a transmission including a DC motor, it is possible to reduce manufacturing costs and simplify the structure of the device, and also provide an actuator having a security function to prevent theft of the vehicle and a control method thereof.

[0018] In addition, according to the means for solving the problem of the present invention described above, an actuator for a transmission including a DC motor and a control method thereof can be provided, which further enhances security performance through synchronized signal transmission using communication.

[0019] However, the effects obtainable from this invention are not limited to those described above, and other effects may exist. Brief explanation of the drawing

[0020] FIG. 1 is a control block diagram of an actuator of a vehicle according to one embodiment of the present invention. FIG. 2 is a schematic diagram showing a circuit included in the control unit of an actuator according to one embodiment of the present invention. FIG. 3 is a schematic diagram showing the configuration of a bidirectional switch circuit included in the control unit of an actuator according to one embodiment of the present invention. FIG. 4 is a control block diagram of an actuator according to another embodiment of the present invention. FIG. 5 is a schematic diagram showing the configuration of a bidirectional switch circuit and a microprocessor connected to the bidirectional switch circuit, which are included in the control unit of an actuator according to another embodiment of the present invention. FIGS. 6(a) and (b) are schematic diagrams illustrating a method of transmitting and receiving synchronized signals through communication in an actuator according to another embodiment of the present invention. FIG. 7 is a flowchart schematically illustrating a control method of an actuator according to another embodiment of the present invention. Specific details for implementing the invention

[0021] Embodiments of the present invention are described below with reference to the attached drawings to enable those skilled in the art to easily implement the invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. Furthermore, in order to clearly explain the present invention in the drawings, parts unrelated to the explanation have been omitted, and similar parts throughout the specification are denoted by similar reference numerals.

[0022] Throughout this specification, when a part is described as being "connected" to another part, this includes not only cases where they are "directly connected," but also cases where they are "electrically connected" or "indirectly connected" with other elements interposed between them.

[0023] Throughout the entire specification, when a component is described as being located "on," "on top," "on top," "under," "on bottom," or "on bottom" of another component, this includes not only cases where the component is in contact with the other component but also cases where another component exists between the two components.

[0024] Throughout this specification, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0025] The present invention relates to an actuator for a vehicle transmission that is equipped with a security circuit to prevent theft, and a control method thereof.

[0026] FIG. 1 is a control block diagram of an actuator of a vehicle according to one embodiment of the present invention.

[0027] Referring to FIG. 1, an actuator (10) according to one embodiment of the present invention may include a DC motor (200) that is driven by the application of current to change the gear ratio, a position sensor (300) for detecting the position of the DC motor (200), and a control unit (100) for controlling the DC motor (200).

[0028] Here, the DC motor (200) may be a DC (direct current) motor equipped with a brush, and may be driven by applying voltage from a power source to allow current to flow, and the gear stage of the transmission may be changed to P stage, D stage, R stage, etc. by rotating the gear stage of the transmission due to the driving of the motor.

[0029] The position sensor (300) may be a Hall sensor installed inside the actuator. The Hall sensor may be configured to detect the position of the DC motor by detecting, for example, the rotation of a magnetic member installed at the end of the rotor shaft of the motor.

[0030] Additionally, the control unit (100) includes a bidirectional switch circuit (110) for controlling the flow of current to the DC motor (200), and can be configured so that the bidirectional switch circuit (110) operates to drive the DC motor (200) when a voltage from the position sensor power supply is applied to the position sensor.

[0031] Meanwhile, the DC motor power supply (20) for driving the DC motor (200) and the sensor power supply (30) for operating the position sensor (300) are connected to the control unit (100) of the actuator to apply voltage to the DC motor (200) and the position sensor (300), respectively.

[0032] According to an actuator (10) according to one embodiment of the present invention having such a configuration, when voltage is applied from a DC motor power source (20) and voltage is applied from a position sensor power source (30), a bidirectional switch circuit (110) can be operated to drive a DC motor (200).

[0033] Meanwhile, such an actuator (10) for a transmission may, more specifically, be an actuator used in a vehicle's shift-by-wire (SBW) system. A shift-by-wire system may refer to a system that controls a vehicle's transmission through an electrical connection structure composed of an electronic shift lever and an electric motor instead of a mechanical connection structure.

[0034] FIG. 2 is a schematic diagram showing a circuit included in the control unit of an actuator according to one embodiment of the present invention.

[0035] As shown in FIG. 2, a control unit (100) of an actuator according to one embodiment of the present invention may include a circuit (motor control circuit) formed such that a first leg (120) including a first switching element (121) and a second switching element (122), and a second leg (130) including a third switching element (131) and a fourth switching element (132) form an H-Bridge shape with a DC motor. The first to fourth switching elements (121, 122, 131, 132) may be Field Effect Transistor (FET) elements.

[0036] Referring to FIG. 2, the voltage (V) from the DC motor power source (e.g., battery) BAT When ) is applied, the current flowing to the DC motor can be controlled by adjusting the on / off state of the first to fourth switching elements (121, 122, 131, 132), and accordingly, the driving of the DC motor can be controlled.

[0037] Meanwhile, as shown in FIG. 2, the control unit (100) may be equipped with a bidirectional switch circuit (110) connected in series with the DC motor to control the flow of current to the DC motor.

[0038] If this bidirectional switch circuit (110) is not operating, even if voltage is applied from the DC motor power supply, current does not flow to the DC motor, so the DC motor cannot be driven. Therefore, the DC motor can be driven when voltage is applied from the DC motor power supply and the bidirectional switch circuit (110) is operating.

[0039] FIG. 3 is a schematic diagram showing the configuration of a bidirectional switch circuit included in the control unit of an actuator according to one embodiment of the present invention.

[0040] As shown in FIG. 3, a bidirectional switch circuit (110) according to one embodiment of the present invention may include an N-channel MOSFET (111) and an FET driving circuit (112). Specifically, the N-channel MOSFET (111) may be configured to include a back-to-back N-channel MOSFET as shown in FIG. 3 to control the flow of current in both directions.

[0041] Meanwhile, the FET driving circuit (112) can drive the N-channel MOSFET (111) to allow bidirectional current to flow when voltage is applied from the position sensor power supply. It is preferable that the voltage applied from the position sensor power supply be 2V or higher, and for example, it may be a power supply voltage of 5V.

[0042] That is, the bidirectional switch circuit (110) can be operated to allow current to flow to the DC motor only when a voltage (e.g., 5V voltage) is applied from the position sensor power supply, so the DC motor can be driven when the position sensor power supply voltage is applied in addition to the DC motor power supply voltage.

[0043] In cases where the gear ratio of the transmission can be changed by driving the DC motor by applying only the motor power voltage as in conventional technology, it is possible to change the gear ratio by connecting only the motor power from the outside, so theft of the vehicle can easily occur.

[0044] In contrast, when the motor is driven only when the position sensor power supply voltage is applied, as in the embodiment of the present invention, the DC motor cannot be driven by applying only the motor power supply voltage from the outside, so the security performance is improved and the theft of the vehicle can be effectively prevented.

[0045] In addition, according to an embodiment of the present invention, since the DC motor can be driven by controlling whether the bidirectional switch circuit operates using the power line of the position sensor provided in the actuator as is, the effect of effectively preventing theft can also be achieved without adding a separate connector for controlling the security circuit.

[0046] FIG. 4 is a control block diagram of an actuator according to another embodiment of the present invention.

[0047] According to an actuator (10') according to another embodiment of the present invention, compared with the embodiment of FIG. 1, the control unit (100') may additionally have a microprocessor (150) connected to the bidirectional switch circuit (110) in addition to the bidirectional switch circuit (110).

[0048] In addition, this microprocessor (150) may be connected to the vehicle's processor (40) via communication. For example, communication between the vehicle's processor (Master) and the actuator's microprocessor (Slave) may be performed using a serial communication protocol such as the I2C protocol or the SPI protocol.

[0049] Meanwhile, communication between the vehicle's processor (40) and the microprocessor (150) can be performed by synchronous transmission. Specifically, the transmission signal and the reception signal are synchronized using a Pulse Width Modulation (PWM) signal, which is the output signal of the position sensor (300), as a reference clock, and the bidirectional switch circuit (110) can be controlled to operate only when the microprocessor (150) receives a predetermined data signal transmitted from the vehicle's processor (40).

[0050] Regarding the synchronous transmission method between the vehicle's processor (40) and the microprocessor (150), we will examine it in more detail in the description of Fig. 6.

[0051] In addition, in addition to receiving a predetermined data signal via communication, when a position sensor power voltage is applied to the position sensor (300), the bidirectional switch circuit (110) may be configured to operate to drive the DC motor (200).

[0052] In addition, the actuator (10') for a transmission according to another embodiment of the present invention may be an actuator for a shift-by-wire system of a vehicle, just like the actuator (10) according to the embodiment of FIG. 1.

[0053] According to the actuator (10') according to another embodiment of the present invention as described above, the DC motor is driven only when a position sensor power voltage is applied and a predetermined data signal is received through communication with the vehicle's processor, thereby enabling an effect that further improves the security performance of the actuator.

[0054] Furthermore, in the transmission of data signals through communication, since the existing position sensor power supply that applies voltage to the position sensor is used as is to synchronize the transmission and reception signals using the output signal of the existing position sensor and to apply voltage to the position sensor, a significant effect can be achieved in that security performance using communication can be improved with a relatively simple configuration by additionally providing only a connector pin for receiving communication data signals.

[0055] FIG. 5 is a schematic diagram showing the configuration of a bidirectional switch circuit and a microprocessor connected to the bidirectional switch circuit, which are included in the control unit of an actuator according to another embodiment of the present invention.

[0056] As can be seen from the configuration of the circuit shown in FIG. 5, the circuit included in the control unit of the actuator according to another embodiment of the present invention may include the configuration of a microprocessor (150) connected to a bidirectional switch circuit (110). The bidirectional switch circuit (110) may include a back-to-back N-channel MOSFET (111) and an FET driving circuit (112), as previously seen in the embodiment of FIG. 3.

[0057] The microprocessor (150) may be configured to receive an output signal from a position sensor and a communication data signal from a vehicle processor. The microprocessor (150) may perform synchronization using the output signal from the position sensor and receive a data signal from the vehicle processor, and control the bidirectional switch circuit (110) to operate only when the data signal is a predetermined data signal.

[0058] In addition, the bidirectional switch circuit (110) can be controlled to operate only when a predetermined communication data signal is received and a position sensor power voltage (e.g., 2V or higher) is applied.

[0059] According to the embodiment of the present invention shown in FIGS. 4 and 5, based on communication between the vehicle's processor (main processor) and the microprocessor equipped in the actuator, the DC motor can be controlled to drive when a predetermined data signal is received, thereby enabling an effect that further enhances the security function of the actuator.

[0060] FIGS. 6(a) and (b) are schematic diagrams illustrating a method of transmitting and receiving synchronized signals through communication in an actuator according to another embodiment of the present invention.

[0061] As shown in FIG. 6(a), synchronization of the transmission signal and the reception signal can be performed by using the position sensor output signal (PWM signal) as a reference clock. Subsequently, the actuator microprocessor, for example, the actuator microprocessor (Slave) used in a Shift-By-Wire (SBW) system, receives a data signal from the vehicle processor (Master), and if this data signal is a predetermined data signal (for example, a signal with a 0X89 data code value), it can send a Signal Low signal (ACK signal), which is a reception acknowledgment signal, to the vehicle processor.

[0062] Meanwhile, referring to FIG. 6(b), if the data signal from the vehicle's processor (Master) is not a predetermined signal, an ACK signal (Signal Low) is not sent and a NACK (not acknowledge) signal (Signal High) may be sent. In this case, a request may be made to the vehicle's processor (Master) to retransmit the data signal. Such a retransmission request may be made a predetermined number of times, and the predetermined number may be, for example, 5 times. However, the present invention is not limited thereto, and the number may be set differently as needed.

[0063] As described above, by enabling the bidirectional switch circuit to operate and drive the DC motor only when it is confirmed that the signal is a predetermined communication signal (sending an ACK signal) through synchronous signal transmission between the vehicle's processor and the microprocessor equipped in the actuator, the theft of the vehicle can be effectively prevented by ensuring thorough security when changing the gear of the vehicle's transmission.

[0064] FIG. 7 is a flowchart schematically illustrating a control method of an actuator according to another embodiment of the present invention.

[0065] According to a control method for an actuator according to another embodiment of the present invention, a step (S100) of receiving a data signal from a processor of a vehicle may first be performed.

[0066] Next, a step (S200) of determining whether the received data signal is a predetermined data signal may be performed. If the received data signal is a predetermined data signal ('Yes' in S200), the bidirectional switch circuit included in the control unit is controlled to operate (Switch ON) (S300), and accordingly, the DC motor may be driven (S400).

[0067] Here, the step (S200) of determining whether the received data signal is a predetermined data signal can be performed by recognizing the received data signal in synchronization with the output signal of a position sensor for detecting the position of a DC motor, and performing an acknowledgment of reception (ACK) for the predetermined data signal.

[0068] Meanwhile, if the received data signal is not a predetermined data signal ('No' in S200), it can be determined whether the number of data receptions has exceeded a predetermined number (S500). If the number of data receptions has not exceeded a predetermined number (e.g., 5 times) ('No' in S500), a request can be made to retransmit the data signal from the vehicle's processor.

[0069] In addition, if the number of data receptions exceeds a predetermined number (e.g., 5 times) ('Yes' in S500), the bidirectional switch circuit included in the control unit becomes OFF (S600), and the DC motor may not be driven (S700).

[0070] Meanwhile, if the number of data receptions exceeds a predetermined number, the DC motor may be controlled to be disabled, and a warning signal (e.g., an auditory signal) may be generated from the vehicle. In this way, if a person attempting to steal the vehicle tries to operate the actuator more than a predetermined number of times, this can be notified to the surroundings of the vehicle.

[0071] According to the control method for an actuator for a vehicle transmission of this kind, by operating a bidirectional switch circuit to drive a DC motor only when the received signal is a predetermined signal through communication with the vehicle's processor, it is possible to provide an actuator with enhanced security performance in an actuator using a DC motor.

[0072] As described above, according to an actuator for a vehicle transmission of one embodiment of the present invention, in an actuator using a DC motor, the operation of the security circuit can be controlled using the position sensor power supply without additional configuration of the device, thereby providing an actuator with excellent security performance by adding a simple configuration of a bidirectional switch circuit.

[0073] In addition, according to an actuator according to another embodiment of the present invention, by using the sensor output of a position sensor as a reference clock to transmit and receive a synchronized signal, and by operating a bidirectional switch circuit only when a predetermined data signal is received, the effect of further improving security performance while minimizing additional configuration for communication can be achieved.

[0074] In addition, according to the control method of an actuator according to another embodiment of the present invention, in the driving control of a DC motor through the transmission and reception of synchronized data signals, by controlling the DC motor so that it does not operate when the data signal is received more than a predetermined number of times, an effect can be achieved that more reliably prevents the theft of a vehicle when a person attempting to steal a vehicle attempts to operate the actuator multiple times.

[0075] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will understand that other specific forms can be easily modified without altering the technical concept or essential features of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single unit may be implemented in a distributed manner, and components described as distributed may likewise be implemented in a combined form.

[0076] The scope of the present invention is defined by the claims set forth below rather than by the detailed description above, and all modifications or variations derived from the meaning and scope of the claims and the concept of equivalents thereof should be interpreted as being included within the scope of the present invention. Explanation of the symbols

[0077] 10, 10': Actuator 20: DC motor power 30: Position sensor power 40: Vehicle processor 100, 100': Control unit 110: Bidirectional switch circuit 111: FET driving circuit 112: N-channel MOSFET 115: Microprocessor 120: 1st Leg 121: First switching element 122: Second switching element 130: 2nd Leg 131: Third switching element 132: 4th switching element 200: DC motor 300: Position sensor

Claims

Claim 1 An actuator for a vehicle comprising: a DC motor that is driven by the application of current to change gear ratios; a position sensor for detecting the position of the DC motor; and a control unit for controlling the DC motor, wherein the control unit comprises a bidirectional switch circuit for controlling the flow of current to the DC motor, and wherein when a voltage from a position sensor power source is applied to the position sensor, the bidirectional switch circuit operates to drive the DC motor, and when a voltage from the position sensor power source is not applied to the position sensor, the bidirectional switch circuit does not operate even if a voltage from a DC motor power source is applied to the DC motor, thereby preventing the DC motor from being driven. Claim 2 An actuator for a vehicle, comprising: a DC motor that is driven by the application of current to change gear ratios; a position sensor for detecting the position of the DC motor; and a control unit for controlling the DC motor, wherein the control unit includes a bidirectional switch circuit for controlling the flow of current to the DC motor and a microprocessor connected to the bidirectional switch circuit, and wherein the bidirectional switch circuit is configured to operate to drive the DC motor when the microprocessor receives a predetermined data signal through communication with a processor of the vehicle. Claim 3 An actuator according to claim 2, wherein the bidirectional switch circuit is configured to operate to drive the DC motor when a voltage from the position sensor power supply is applied to the position sensor and the microprocessor receives the predetermined data signal. Claim 4 An actuator according to claim 2, wherein the microprocessor recognizes a received data signal in synchronization with the output signal of the position sensor, determines whether it is the predetermined data signal, and operates the bidirectional switch circuit when a reception acknowledgment signal is transmitted. Claim 5 An actuator according to claim 2, wherein the microprocessor requests the retransmission of a data signal a predetermined number of times when the received data signal is not the predetermined data signal, and controls the bidirectional switch circuit not to operate when the reception of the data signal exceeds the predetermined number of times. Claim 6 A method for controlling an actuator of a vehicle, comprising: receiving a data signal from a processor of the vehicle; determining whether the received data signal is a predetermined data signal; if the received data signal is a predetermined data signal, operating a bidirectional switch circuit for controlling the flow of current to a DC motor; and driving the DC motor. Claim 7 A method for controlling an actuator according to claim 6, wherein the step of determining whether the received data signal is a predetermined data signal is characterized by recognizing the received data signal in synchronization with the output signal of a position sensor for detecting the position of the DC motor, and transmitting a reception acknowledgment signal when it is determined to be the predetermined data signal. Claim 8 A method for controlling an actuator according to claim 6, characterized in that, in the step of determining whether the data signal is a predetermined data signal, if it is determined that the data signal is not a predetermined data signal, a request to resend the data signal is transmitted to the processor of the vehicle, and if the data signal is received more than a predetermined number of times by repeating the resend request, the bidirectional switch circuit is controlled not to operate.

Images