Electro mechanical brake system and operating method thereof

Abstract

The present invention relates to an electric brake system and a method of operating the same. According to one aspect of the present invention, the electric brake system comprises: a motor operated for braking a vehicle; a first electronic control unit electrically connected to the motor and controlling the driving of the motor; and a second electronic control unit electrically connected to the motor and controlling the driving of the motor. The first electronic control unit calculates a current command value using a command pressure for braking and outputs a PWM duty using the calculated current command value, and the second electronic control unit can output a PWM duty using the current command value calculated by the first electronic control unit.

Description

Technology Field

[0001] The present invention relates to an electric brake system and a method of operating the same, and more specifically, to an electric brake system and a method of operating the same that can efficiently control the brake in a normal state. Background Technology

[0002] Vehicles necessarily include a braking system for braking. Recently, to obtain more powerful and stable braking force, these braking systems electronically control the braking hydraulic pressure transmitted to the wheel cylinders mounted on the wheels.

[0003] Conventional braking systems utilize a method in which the driver presses the brake pedal, using a mechanically connected booster to supply the hydraulic pressure required for braking to the wheel cylinders. However, as the demand for effective braking functions in various environments that respond precisely to the vehicle's operating conditions increases, electric braking systems are being utilized. These electric braking systems use a pedal displacement sensor that detects the displacement of the brake pedal when the driver presses it to convert the driver's intention to brake into a signal, and utilize a hydraulic pressure supply device that supplies the necessary hydraulic pressure to the wheel cylinders based on the signal.

[0004] Such electric brake systems are controlled by signals output from an electronic control unit, and if a problem occurs with the electronic control unit, key components do not operate, resulting in a problem where the hydraulic pressure required for braking is not stably formed. Prior art literature

[0005] Republic of Korea Published Patent No. 10-2020-0140752 (December 16, 2020) United States Published Patent No. 2017-0282877 (October 5, 2017) The problem to be solved

[0006] Embodiments of the present invention were invented against the background described above, and aim to provide an electric brake system capable of generating braking pressure according to the driver's will when both electronic control units in the electric brake system are in a normal state, and a method of operating the same. means of solving the problem

[0007] According to one aspect of the present invention, an electric brake system comprises: a motor operated for braking a vehicle; a first electronic control unit electrically connected to the motor and controlling the driving of the motor; and a second electronic control unit electrically connected to the motor and controlling the driving of the motor, wherein the first electronic control unit calculates a current command value using a command pressure for braking and outputs a PWM duty using the calculated current command value, and the second electronic control unit can output a PWM duty using the current command value calculated by the first electronic control unit.

[0008] The first electronic control unit outputs a PWM duty using a portion of the calculated current command value, and the second electronic control unit can output a PWM duty using the remainder of the current command value calculated by the first electronic control unit.

[0009] The first electronic control unit may include: a pressure control unit that calculates a torque value of the motor for braking using a commanded pressure; a speed control unit that calculates a current command value for controlling the speed of the motor; and a first current control unit that calculates a PWM duty using a portion of the current command value calculated by the speed control unit.

[0010] The second electronic control unit may include a second current control unit that calculates the PWM Duty using the remainder of the current command value calculated by the speed control unit.

[0011] The first electronic control unit can receive the PWM Duty calculated by the first current control unit and convert and output power so that it can be applied to the motor.

[0012] The first current control unit calculates the PWM Duty using half of the calculated current command value, and

[0013] The second current control unit above can calculate the PWM Duty using half of the calculated current command value.

[0014] The first current control unit and the second current control unit can calculate the PWM Duty using the same current command value.

[0015] The first electronic control unit outputs a PWM duty using a calculated current command value, and the second electronic control unit can receive and output the PWM duty calculated by the first electronic control unit.

[0016] The first electronic control unit may include: a pressure control unit that calculates a torque value of the motor for braking using a commanded pressure; a speed control unit that calculates a current command value for controlling the speed of the motor; a first current control unit that calculates a PWM duty using the current command value calculated by the speed control unit; and a first power conversion unit that outputs the PWM duty calculated by the first current control unit.

[0017] The second electronic control unit may include a second power converter that receives and outputs a PWM duty calculated by the first current control unit.

[0018] The above motor may be a three-phase permanent magnet synchronous motor.

[0019] The first electronic control unit and the second electronic control unit may both be in a normal state.

[0020] Meanwhile, a method of operating an electric brake system according to one embodiment of the present invention may include: a step of inputting a command pressure to a first electronic control unit so that a motor is operated for braking a vehicle; a step of calculating a motor torque value in the first electronic control unit according to the input command pressure; a step of calculating a current command value for the total torque output of the motor in the first electronic control unit; a step of outputting a PWM duty from the first electronic control unit using the calculated current command value; and a step of outputting a PWM duty from a second electronic control unit using the current command value calculated in the first electronic control unit.

[0021] In the step where the PWM Duty is output from the first electronic control unit, the PWM Duty can be calculated and output using a part of the calculated current command value.

[0022] The method further includes a step in which a PWM Duty is calculated in the second electronic control unit using the remainder of the calculated current command value, and the step in which the PWM Duty is output from the second electronic control unit may output the PWM Duty calculated in the second electronic control unit.

[0023] The first electronic control unit and the second electronic control unit can calculate the PWM duty using the same current command value.

[0024] The first electronic control unit calculates the PWM Duty using half of the calculated current command value, and the second electronic control unit can calculate the PWM Duty using half of the calculated current command value.

[0025] The step in which the PWM Duty is output from the second electronic control unit may be such that the PWM Duty calculated in the first electronic control unit is output.

[0026] The method further includes a step of transmitting the PWM Duty calculated in the first electronic control unit to the second electronic control unit, and the step of outputting the PWM Duty from the second electronic control unit may be such that the PWM Duty transmitted from the first electronic control unit is output.

[0027] The first electronic control unit and the second electronic control unit may both be in a normal state. Effects of the invention

[0028] One embodiment of the present invention utilizes two electronic control units in an electric brake system, so that even if a problem occurs in one electronic control unit, braking force can be maintained by using the other electronic control unit, thereby increasing stability.

[0029] In addition, reducing the current generated by the two electronic control units allows for a lower maximum performance requirement for electronic components, which in turn reduces heat generation, improves durability, and enhances price competitiveness. Brief explanation of the drawing

[0030] FIG. 1 is a block diagram illustrating an electric brake system according to a first embodiment of the present invention. FIG. 2 is a flowchart illustrating the operation method of an electric brake system according to a first embodiment of the present invention. FIG. 3 is a block diagram illustrating an electric brake system according to a second embodiment of the present invention. FIG. 4 is a flowchart illustrating the operation method of an electric brake system according to a second embodiment of the present invention. Specific details for implementing the invention

[0031] Embodiments of the present invention will be described in detail below with reference to the drawings. The embodiments introduced below are provided as examples to ensure that the concept of the present invention is sufficiently conveyed to those skilled in the art to which the present invention pertains. The present invention is not limited to the embodiments described below and may be embodied in other forms. To clearly explain the present invention, parts unrelated to the description have been omitted from the drawings, and in the drawings, the width, length, thickness, etc., of components may be exaggerated for convenience. Throughout the specification, the same reference numerals indicate the same components.

[0032] Referring to FIG. 1, an electric brake system (100) according to a first embodiment of the present invention will be described. The electric brake system (100) according to a first embodiment of the present invention includes a first electronic control unit (110), a second electronic control unit (120), and a motor (130).

[0033] The first electronic control unit (110) controls the torque of the motor (130) to generate braking pressure according to the driver's braking intention and is electrically connected to the motor (130). This first electronic control unit (110) includes a first merging unit (111), a pressure control unit (112), a speed control unit (114), a second merging unit (115), a first current control unit (116), and a first power conversion unit (118).

[0034] The first merging unit (111) receives the command pressure and the measured pressure. The command pressure and the measured pressure input through the first merging unit (111) are output to the pressure control unit (112). The command pressure is a pressure value for setting and commanding the pressure required for braking the brake, and the measured pressure is the pressure measured from the hydraulic pressure used for brake braking.

[0035] The pressure control unit (112) receives the command pressure and the measured pressure from the first merging unit (111), controls the hydraulic pressure required for brake braking using the received command pressure and the measured pressure, and calculates the torque value of the motor (130).

[0036] The speed control unit (114) calculates a command value for the current for the total torque output so as to control the speed of the motor (130). The speed control unit (114) outputs a portion of the calculated current command value to the first current control unit (116) and outputs the remainder of the calculated current command value to the second electronic control unit (120). For example, the speed control unit (114) outputs half of the calculated current command value to the first current control unit (116) and outputs the remaining half to the second electronic control unit (120).

[0037] The second merging unit (115) receives a portion of the calculated current command value output from the speed control unit (114) and also receives a current value measured from the motor (130). The second merging unit (115) transmits the portion of the calculated current command value from the speed control unit (114) and the current value measured from the motor (130) to the first current control unit (116).

[0038] The first current control unit (116) calculates the PWM Duty using a portion of the current command value calculated in the second merging unit (115) and the measured current value, and outputs the calculated PWM Duty.

[0039] The first power conversion unit (118) receives the PWM Duty calculated by the first current control unit (116), converts the power so that it can be applied to the motor (130), and outputs the PWM Duty.

[0040] The second electronic control unit (120) controls the torque of the motor (130) to generate braking pressure according to the driver's braking intention and is electrically connected to the motor (130). This second electronic control unit (120) includes a third merging unit (125), a second current control unit (126), and a second power conversion unit (128).

[0041] The third merging unit (125) receives the remainder of the calculated current command value output from the speed control unit (114) of the first electronic control unit (110), and also receives the current value measured from the motor (130). For example, the speed control unit (114) outputs half of the calculated current command value to the second merging unit (115) and the remainder half to the third merging unit (125) of the second electronic control unit (120). The second merging unit (115) transmits a portion of the calculated current command value from the speed control unit (114) and the current value measured from the motor (130) to the second current control unit (126).

[0042] The second current control unit (126) calculates the PWM Duty using a portion of the current command value calculated by the third merging unit (125) and the measured current value, and outputs the calculated PWM Duty.

[0043] The second power conversion unit (128) receives the PWM Duty calculated by the second current control unit (126), converts the power so that it can be applied to the motor (130), and outputs the PWM Duty.

[0044] The motor (130) receives a PWM Duty through the first power converter (118) and the second power converter (128), respectively, and can be driven by the received PWM Duty. The motor (130) may be a synchronous motor (130) using a three-phase permanent magnet and may be configured in a double winding manner.

[0045] Referring to FIG. 2, a method of operation of an electric brake system (100) according to a first embodiment of the present invention will be described. While describing the method of operation of an electric brake system (100) according to a first embodiment of the present invention, the method will be described with reference to FIG. 1.

[0046] When braking is initiated in the electric brake system (100), check whether a command pressure is input (S111).

[0047] It is checked whether a command pressure is input to the pressure control unit (112) of the first electronic control unit (110) via the first merging unit (111), and if a command pressure is not input to the pressure control unit (112), it waits until a command pressure is input and continuously checks.

[0048] When a command pressure is input, the motor (130) torque value according to pressure control is calculated (S113).

[0049] The pressure control unit (112) of the first electronic control unit (110) controls the hydraulic pressure required for brake braking using the input command pressure and the measured pressure, and calculates the torque value of the motor (130). Here, the command pressure is a pressure value for setting and commanding the pressure required for brake braking, and the measured pressure is the pressure measured for the hydraulic pressure used for brake braking.

[0050] When the torque value of the motor (130) is calculated, a current command for the total torque output is calculated (S115).

[0051] To control the speed of the motor (130), a command value for the current for the total torque output is calculated in the speed control unit (114) of the first electronic control unit (110). The speed control unit (114) outputs a portion of the calculated current command value to the first current control unit (116) and outputs the remainder of the calculated current command value to the second electronic control unit (120).

[0052] Outputs PWM Duty (S117).

[0053] The PWM Duty is calculated in the first current control unit (116) of the first electronic control unit (110) using a portion of the current command value calculated in the speed control unit (114) and the current value measured in the motor (130). Using the PWM Duty calculated in the first current control unit (116), the first power conversion unit (118) of the first electronic control unit (110) converts power and outputs the PWM Duty.

[0054] The remainder of the command value of the calculated current is received (S125).

[0055] The remainder of the current command value calculated from the speed control unit (114) of the first electronic control unit (110) is received by the second current control unit (126) of the second electronic control unit (120). For example, the speed control unit (114) outputs half of the calculated current command value to the second merging unit (115) and outputs the remainder half to the third merging unit (125) of the second electronic control unit (120). The second merging unit (115) transmits a portion of the current command value calculated from the speed control unit (114) and the current value measured by the motor (130) to the second current control unit (126).

[0056] Outputs PWM Duty (S127).

[0057] The PWM Duty is calculated in the second current control unit (126) of the second electronic control unit (120) using a portion of the current command value calculated in the speed control unit (114) and the current value measured in the motor (130). Using the PWM Duty calculated in the second current control unit (126), the second power conversion unit (128) of the second electronic control unit (120) converts power and outputs the PWM Duty.

[0058] As described above, the PWM Duty output from steps S117 and S127, respectively, is transmitted to the motor (130), and the motor (130) is driven using the transmitted PWM Duty so that the brake system can be operated. After the brake system is operated in this way, it can be stopped.

[0059] Referring to FIG. 3, an electric brake system (100) according to a second embodiment of the present invention will be described. The electric brake system (100) according to the second embodiment of the present invention includes a first electronic control unit (110), a second electronic control unit (120), and a motor (130). While describing the second embodiment of the present invention, descriptions identical to those in the first embodiment will be omitted.

[0060] The first electronic control unit (110) includes a first merging unit (111), a pressure control unit (112), a speed control unit (114), a second merging unit (115), a first current control unit (116), and a first power conversion unit (118), and the second electronic control unit (120) includes a third merging unit (125) and a second power conversion unit (128).

[0061] The speed control unit (114) of the first electronic control unit (110) calculates a command value for the current for the total torque output so as to control the speed of the motor (130). The speed control unit (114) outputs the calculated current command value to the first current control unit (116) of the first electronic control unit (110).

[0062] The first current control unit (116) of the first electronic control unit (110) calculates the PWM Duty using the current command value calculated in the second merging unit (115) and the measured current value, and outputs the calculated PWM Duty.

[0063] The first power conversion unit (118) of the first electronic control unit (110) receives the PWM Duty calculated by the first current control unit (116), converts the power so that it can be applied to the motor (130), and outputs the PWM Duty.

[0064] The second power conversion unit (128) of the second electronic control unit (120) receives the PWM Duty calculated by the first current control unit (116) of the first electronic control unit (110), converts the power so that it can be applied to the motor (130), and outputs the PWM Duty.

[0065] Referring to FIG. 4, a method of operation of an electric brake system (100) according to a second embodiment of the present invention will be described. While describing the method of operation of an electric brake system (100) according to a second embodiment of the present invention, the description will be made with reference to FIG. 3. While describing the second embodiment of the present invention, descriptions identical to those in the first embodiment will be omitted.

[0066] When braking is initiated in the electric brake system (100), check whether a command pressure is input (S211).

[0067] It is checked whether a command pressure is input to the pressure control unit (112) of the first electronic control unit (110) via the first merging unit (111), and if a command pressure is not input to the pressure control unit (112), it waits until a command pressure is input and continuously checks.

[0068] When a command pressure is input, the motor (130) torque value according to pressure control is calculated (S213).

[0069] The pressure control unit (112) of the first electronic control unit (110) controls the hydraulic pressure required for brake braking using the input command pressure and the measured pressure, and calculates the torque value of the motor (130). Here, the command pressure is a pressure value for setting and commanding the pressure required for brake braking, and the measured pressure is the pressure measured for the hydraulic pressure used for brake braking.

[0070] When the torque value of the motor (130) is calculated, a current command for the total torque output is calculated (S215).

[0071] To control the speed of the motor (130), a command value for the current for the total torque output is calculated in the speed control unit (114) of the first electronic control unit (110). The speed control unit (114) outputs the calculated current command value to the first current control unit (116) of the first electronic control unit (110).

[0072] Outputs PWM Duty (S217).

[0073] The PWM Duty is calculated in the first current control unit (116) of the first electronic control unit (110) using the current command value calculated in the speed control unit (114) and the current value measured in the motor (130). Using the PWM Duty calculated in the first current control unit (116), the first power conversion unit (118) of the first electronic control unit (110) converts power and outputs the PWM Duty.

[0074] Receives and outputs PWM Duty (S227).

[0075] The second power conversion unit (128) of the second electronic control unit (120) converts power using the PWM Duty calculated by the first current control unit (116) and outputs the PWM Duty.

[0076] The motor (130) receives a PWM Duty through the first power converter (118) and the second power converter (128), respectively, and can be driven by the received PWM Duty. Explanation of the symbols

[0077] 100: Electric brake system 110: 1st Electronic Control Unit 111: 1st Merging Unit 112: Pressure Control Unit 114: Speed ​​control unit 115: Second merging unit 116: First current control unit 118: First power conversion unit 120: Second Electronic Control Unit 125: 3rd Merging Unit 126: 2nd Current Control Unit 128: Second power converter 130: Motor

Claims

Claim 1 An electric brake system comprising: a motor operated for braking a vehicle; a first electronic control unit electrically connected to the motor and controlling the operation of the motor; and a second electronic control unit electrically connected to the motor and controlling the operation of the motor, wherein the first electronic control unit calculates a current command value using a command pressure for braking, transmits a portion of the calculated current command value or a second PWM Duty to the second electronic control unit, outputs a first PWM Duty using the calculated current command value, and the second electronic control unit outputs a second PWM Duty in response to receiving the portion of the current command value or the second PWM Duty from the first electronic control unit, and the second PWM Duty is calculated by the first electronic control unit or the second electronic control unit using the current command value calculated in the first electronic control unit. Claim 2 An electric brake system according to claim 1, wherein the first electronic control unit outputs the first PWM Duty using a portion of the current command value calculated by the first electronic control unit, and the second electronic control unit outputs the second PWM Duty using the portion of the current command value corresponding to the remainder of the current command value calculated by the first electronic control unit. Claim 3 An electric brake system according to claim 1, wherein the first electronic control unit comprises: a pressure control unit that calculates a torque value of the motor for braking using a command pressure; a speed control unit that calculates a current command value for controlling the speed of the motor; and a first current control unit that calculates the first PWM Duty using a portion of the current command value calculated by the speed control unit. Claim 4 In claim 3, the electric brake system, wherein the second electronic control unit comprises a second current control unit that calculates the second PWM Duty using the partial current command value corresponding to the remainder of the current command value calculated by the speed control unit. Claim 5 In claim 3, the first electronic control unit receives the first PWM Duty calculated by the first current control unit and converts and outputs power so that it can be applied to the motor, an electric brake system. Claim 6 An electric brake system according to claim 4, wherein the first current control unit calculates the first PWM Duty using half of the current command value calculated by the speed control unit, and the second current control unit calculates the second PWM Duty using half of the current command value calculated by the speed control unit. Claim 7 An electric brake system according to claim 4, wherein the first PWM Duty and the second PWM Duty are calculated using the same current command value. Claim 8 An electric brake system according to claim 1, wherein the first electronic control unit outputs the first PWM Duty using the calculated current command value, and the second electronic control unit receives and outputs the second PWM Duty calculated by the first electronic control unit. Claim 9 An electric brake system according to claim 1, wherein the first electronic control unit comprises: a pressure control unit that calculates a torque value of the motor for braking using a command pressure; a speed control unit that calculates a current command value for controlling the speed of the motor; a first current control unit that calculates the first PWM Duty using the current command value calculated by the speed control unit; and a first power conversion unit that outputs the first PWM Duty calculated by the first current control unit. Claim 10 In claim 9, the electric brake system, wherein the second electronic control unit includes a second power converter that receives and outputs the second PWM Duty calculated by the first current control unit. Claim 11 An electric brake system according to claim 1, wherein the motor is a three-phase permanent magnet synchronous motor. Claim 12 An electric brake system according to claim 1, wherein the first electronic control unit and the second electronic control unit are both in a normal state. Claim 13 A step in which a command pressure is input to a first electronic control unit so that the motor operates for braking the vehicle; a step in which a motor torque value is calculated in the first electronic control unit according to the input command pressure; a step in which a current command value for the total torque output of the motor is calculated in the first electronic control unit; a step in which a portion of the calculated current command values ​​or a second PWM Duty is transmitted from the first electronic control unit to the second electronic control unit; and a step in which a first PWM Duty is output from the first electronic control unit using the calculated current command values. A method of operating an electric brake system, wherein the second electronic control unit, in response to receiving the partial current command value or the second PWM Duty from the first electronic control unit, outputs the second PWM Duty from the second electronic control unit, and the second PWM Duty is calculated by the first electronic control unit or the second electronic control unit using the current command value calculated in the first electronic control unit. Claim 14 In claim 13, the step of outputting the first PWM Duty from the first electronic control unit is a method of operation of an electric brake system in which the first PWM Duty is calculated and output using a part of the calculated current command value. Claim 15 A method of operation of an electric brake system according to claim 14, further comprising the step of calculating the second PWM Duty in the second electronic control unit using the partial current command value corresponding to the remainder of the calculated current command value, and the step of outputting the second PWM Duty from the second electronic control unit is the second PWM Duty calculated in the second electronic control unit being output. Claim 16 A method of operation of an electric brake system according to claim 15, wherein the first PWM Duty and the second PWM Duty are calculated using the same current command value. Claim 17 A method of operation of an electric brake system according to claim 15, wherein the first electronic control unit calculates the first PWM Duty using half of the calculated current command value, and the second electronic control unit calculates the second PWM Duty using half of the calculated current command value. Claim 18 In claim 13, the step of outputting the second PWM Duty from the second electronic control unit is a method of operating an electric brake system in which the second PWM Duty calculated in the first electronic control unit is output. Claim 19 delete Claim 20 A method of operating an electric brake system according to claim 13, wherein the first electronic control unit and the second electronic control unit are both in a normal state.

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