Engine control unit and engine control system

Abstract

Engine control unit (10), comprising: an acceleration sensor (2) arranged on a circuit board (50), which detects an acceleration as a function of a position of the circuit board (50) and outputs the detected acceleration as acceleration information; a temperature sensor (3) arranged on the circuit board (50), which detects a temperature on the circuit board (50) and outputs the detected temperature as a detected temperature; an inverter circuit (8) arranged on the circuit board (50) which drives a motor (20); and a control circuit (1) arranged on the circuit board (50), which calculates position information indicating the position of the circuit board (50) based on the acceleration information, calculates temperature information indicating a temperature of a part arranged on the circuit board (50) based on the detected temperature, and controls the inverter circuit (8) by outputting a power supply command for the motor (20) to the inverter circuit (8), which power supply command is based on a temperature threshold value set for each item of the position information, the position information, and the temperature information.

Description

Area

[0001] The present disclosure relates to an engine control device and an engine control system that control an engine. background

[0002] A motor control unit includes an inverter circuit that supplies power to a motor, such as a servo motor. In the motor control unit, the inverter circuit generates heat during operation of the inverter circuit, and the temperature inside the motor control unit increases. Therefore, in a typical motor control unit, a heat dissipator for dissipating heat is provided in a case in which the inverter circuit is housed. In the typical motor control unit, a temperature sensor is also provided that detects the temperature of the heat dissipator and stops the operation of the inverter circuit depending on the detected temperature. Furthermore, there is a case where the motor control unit is installed in various installation positions depending on a device to be driven or other devices.In such an engine control unit, it is known that an effect of heat generation of the inverter circuit on heat generation of the entire engine control unit varies greatly depending on the installation position of the engine control unit.

[0003] Therefore, a motor control device described in Patent Literature 1 detects a tilt of a housing by an acceleration sensor disposed in the housing for accommodating an inverter circuit, and detects a temperature of a heat sink by a temperature sensor disposed in the heat sink of the housing. Then, based on the detected tilt value and the detected temperature, the motor control device described in Patent Literature 1 determines whether or not the temperature of the motor control device has an abnormality, and the motor control device stops operation of a motor in a case where the temperature has an abnormality.

[0004] Patent Literature 2 discloses a motor drive device comprising: an AC-stabilized power supply configured to convert an AC voltage of a commercial AC power source into an input supply voltage and output the input supply voltage according to a received voltage command value; a converter configured to convert the input supply voltage into a DC voltage and output the DC voltage to a DC link; an inverter configured to convert the DC voltage in the DC link into an AC voltage for driving a motor; and an input supply voltage control unit configured to control the input supply voltage output by the AC-stabilized power supply. Citation listPatent literature Patent literature 1: JP 2012 - 34 427 A Patent literature 2: US 2020 / 0 052 642 A1 Brief description of the inventionProblem to be solved by the invention

[0005] However, in the technique of Patent Literature 1, when a part whose temperature is to be detected is mounted on a circuit board, the temperature detected by a temperature sensor is the temperature of a heat sink, and there is a large error between the temperature detected by the temperature sensor and the actual temperature of the part. Furthermore, the engine control device described in Patent Literature 1 acquires an installation position of the engine control device by detecting an inclination of a housing using an acceleration sensor arranged in the housing.However, in a case where an installation position of the circuit board on which the part whose temperature is to be detected is mounted changes independently of the housing, or in a case where the housing is not present, the engine control device cannot acquire the installation position of the circuit board on which the part whose temperature is to be detected is mounted. Therefore, there is a problem in that the engine control device described in Patent Literature 1 cannot control the engine depending on an accurate heat generation state of the part mounted on the circuit board.

[0006] The present disclosure has been made in view of the above, and an object of the present disclosure is to provide an engine control apparatus which can control an engine depending on an accurate heat generation state of a part mounted on a circuit board. Means of solving the problem

[0007] To solve the above-mentioned problems and achieve the object, an engine control device according to the present disclosure includes: an acceleration sensor disposed on a circuit board, which detects an acceleration depending on a position of the circuit board and outputs the detected acceleration as acceleration information; and a temperature sensor disposed on the circuit board, which detects a temperature on the circuit board and outputs the detected temperature as detected temperature.The motor control device according to the present disclosure further includes: an inverter circuit arranged on the circuit board, which drives a motor; and a control circuit arranged on the circuit board, which calculates position information indicating the position of the circuit board based on the acceleration information, calculates temperature information indicating a temperature of a part arranged on the circuit board based on the detected temperature, and controls the inverter circuit by outputting to the inverter circuit a power supply command for the motor based on a temperature threshold set for each piece of the position information, the position information, and the temperature information. Effects of the invention

[0008] A motor control apparatus according to the present disclosure achieves an effect that it is possible to control a motor depending on an accurate heat generation state of a part mounted on a circuit board. Short description of the drawings Fig. 1 is a diagram showing a configuration of a circuit board including an engine control device according to an embodiment. Fig. 2 is a diagram showing an example of an arrangement configuration of parts on a printed circuit board according to the embodiment. Fig. 3 is a diagram showing a configuration of an engine control system including the engine control device according to the embodiment. Fig. 4 is a diagram showing an example of a hardware configuration for implementing a control circuit included in the control device according to the embodiment. Description of embodiments

[0009] Hereinafter, an engine control apparatus and an engine control system according to an embodiment of the present disclosure will be described in detail with reference to the drawings. Embodiment.

[0010] Fig. 1 is a diagram showing a configuration of a circuit board including an engine control unit according to an embodiment. Each part included in an engine control unit 10 is arranged on a circuit board 50. The engine control unit 10 is connected to a motor 20, such as a servo motor, and controls the motor 20.

[0011] The motor control unit 10 includes a control circuit 1, an acceleration sensor 2, a temperature sensor 3, and an inverter circuit 8 that drives the motor 20. That is, the control circuit 1, the acceleration sensor 2, the temperature sensor 3, and the inverter circuit 8 are all arranged on the circuit board 50. The control circuit 1 includes an installation orientation calculation unit 4, a temperature calculation unit 5, a constraint information storage unit 6, and a heat generation determination unit 7.

[0012] The temperature sensor 3 detects the temperature on the engine control unit 10 and sends a detected temperature indicating the detected temperature to the temperature calculation unit 5. An example of the temperature sensor 3 is a temperature thermistor. The temperature calculation unit 5 calculates temperature information indicating the temperature of a part (for example, the inverter circuit 8) whose temperature is being monitored based on the detected temperature detected by the temperature sensor 3.

[0013] Note that the part whose temperature is monitored can be any part on the circuit board 50. However, in the present embodiment, a case is described in which the part whose temperature is monitored is the inverter circuit 8 on the circuit board 50. The temperature calculation unit 5 sends the calculated temperature information of the inverter circuit 8 to the heat generation determination unit 7.

[0014] The acceleration sensor 2 detects accelerations in three axis directions of the engine control unit 10, including an X-axis direction, a Y-axis direction, and a Z-axis direction, which are orthogonal to each other, and sends acceleration information indicating the detected acceleration to the installation orientation calculation unit 4. The Z-axis direction is, for example, a vertical direction, and an XY plane is a horizontal plane.

[0015] The installation orientation calculation unit 4 calculates posture information indicating the orientation in which the circuit board 50 functioning as the engine control unit 10 is installed (installation orientation) based on the acceleration information sent from the acceleration sensor 2. The installation orientation calculation unit 4 calculates posture information indicating inclinations in the three axis directions, including the X-axis direction, the Y-axis direction, and the Z-axis direction, of the engine control unit 10. The installation orientation calculation unit 4 sends the calculated posture information to the heat generation determination unit 7.

[0016] The restriction information storage unit 6 is a memory or the like that stores restriction information 9 in advance. The restriction information 9 is information indicating a first temperature threshold and a second temperature threshold set for each piece of posture information. That is, in the restriction information 9, the posture information is associated with the first temperature threshold and the second temperature threshold. Thus, in the present embodiment, the first temperature threshold and the second temperature threshold are set for each posture of the circuit board 50. The second temperature threshold is a value greater than the first temperature threshold. The first temperature threshold is a threshold used to determine whether or not to reduce the power supply amount to the motor 20.The second temperature threshold is a threshold used to determine whether or not to stop the power supply to the motor 20. That is, the first temperature threshold is an upper temperature limit when determining to reduce the power supply amount to the motor 20, and the second temperature threshold is an upper temperature limit when determining to stop the power supply to the motor 20.

[0017] The first temperature threshold and the second temperature threshold are set based on the arrangement relationship between a monitoring target part (inverter circuit 8 in the present embodiment), which is the part whose temperature is monitored, on the circuit board 50, and the temperature sensor 3 or the like. The arrangement relationship is a distance between the monitoring target part and the temperature sensor 3, a thermal conductivity between the monitoring target part and the temperature sensor 3, or the like. That is, the first temperature threshold and the second temperature threshold are set based on the distance between the monitoring target part and the temperature sensor 3, the thermal conductivity between the monitoring target part and the temperature sensor 3, or the like.Furthermore, the first temperature threshold and the second temperature threshold are set for each item of position information.

[0018] The heat generation determination unit 7 receives the posture information from the installation orientation calculation unit 4 and receives the temperature information from the temperature calculation unit 5. Further, the heat generation determination unit 7 reads the restriction information 9 (first temperature threshold and second temperature threshold) associated with the posture information from the restriction information storage unit 6.

[0019] The heat generation determination unit 7 determines whether or not to reduce the power supply amount based on the posture information calculated by the installation orientation calculation unit 4, the temperature information calculated by the temperature calculation unit 5, and the first temperature threshold. Furthermore, the heat generation determination unit 7 determines whether or not to stop the power supply based on the posture information calculated by the installation orientation calculation unit 4, the temperature information calculated by the temperature calculation unit 5, and the second temperature threshold.

[0020] The heat generation determination unit 7 determines a power supply command to be output to the inverter circuit 8 based on the temperature information, the position information, and the restriction information 9. When the temperature information exceeds the first temperature threshold associated with the position information, the heat generation determination unit 7 outputs the power supply command to the inverter circuit 8 to reduce the power supply. That is, when the temperature information exceeds the first temperature threshold associated with the position information, the heat generation determination unit 7 reduces the amount of power supplied to the motor 20 by controlling the inverter circuit 8, thereby preventing heat generation of the motor control unit 10.Note that the power supply command for reducing the power supply is, for example, a command for reducing a current value and / or a voltage value below a current value or a voltage value of the power supply command outputted to the inverter circuit 8 at a previous time, a command for correcting the current value and / or the voltage value of the power supply command to be reduced, or the like.

[0021] Furthermore, in a case where the temperature information exceeds the second temperature threshold associated with the position information, the heat generation determination unit 7 outputs the power supply command to stop the power supply to the inverter circuit 8. That is, in a case where the temperature information exceeds the second temperature threshold associated with the position information, the heat generation determination unit 7 stops the power supply to the motor 20 by controlling the inverter circuit 8, and this prevents the heat generation of the motor control unit 10.Note that the power supply command for stopping the power supply is, for example, a command for setting the current value and / or the voltage value to zero, a command for correcting the current value and / or the voltage value of the power supply command output to the inverter circuit 8 to zero, a command for blocking the power supply command output to the inverter circuit 8, or the like.

[0022] For example, in a case where the temperature information exceeds the first temperature threshold associated with the position information of the circuit board 50 and does not exceed the second temperature threshold, the heat generation determination unit 7 controls the amount of power supplied to the motor 20 to an amount that depends on the temperature information. That is, in a case where the temperature information exceeds the first temperature threshold associated with the position information of the circuit board 50 and does not exceed the second temperature threshold, the heat generation determination unit 7 outputs a command to the inverter circuit 8 to reduce the amount of power supplied to the motor 20, the higher the temperature indicated by the temperature information, the greater the reduction.

[0023] Note that, in a case where the temperature information exceeds the first temperature threshold associated with the position information of the circuit board 50 and does not exceed the second temperature threshold, the heat generation determination unit 7 may control the power supply amount to the motor 20 to a fixed amount.

[0024] In the engine control unit 10, the position of the engine control unit 10 is determined based on the position of the circuit board 50. Furthermore, depending on the position of the circuit board 50, the position information between the temperature sensor 3 and a part of the engine control unit 10 other than the temperature sensor 3 (inverter circuit 8 in the embodiment) arranged on the circuit board 50 is determined. Then, the temperature detected by the temperature sensor 3 varies depending on the position information according to a positional relationship between the temperature sensor 3 and the inverter circuit 8.For example, the temperature detected by the temperature sensor 3 in a case where the position of the circuit board 50 is a position where the temperature sensor 3 is at an upper side of the inverter circuit 8 is different from a case where the position of the circuit board 50 is a position where the temperature sensor 3 is at a lower side of the inverter circuit 8. The motor control device 10 according to the present embodiment determines a heat generation state of the inverter circuit 8 based on the temperature information corresponding to the detected temperature detected by the temperature sensor 3 on the circuit board 50, the position information of the motor control device 10 (circuit board 50), and the restriction information 9. Then, the motor control device 10 controls the power supply amount to the motor 20 depending on the heat generation state of the inverter circuit 8.

[0025] In this way, the control circuit 1 controls the inverter circuit 8 by outputting the power supply command for the motor 20, which is based on the temperature threshold value (first and second temperature threshold values) set for each piece of the position information, the position information, and the temperature information, to the inverter circuit 8. This means that because the motor control device 10 can determine the heat generation state of the inverter circuit 8 based on the position information, it is possible to accurately monitor the temperature of the inverter circuit 8.

[0026] Fig. Figure 2 is a diagram showing an example of a layout configuration of parts on the circuit board according to the embodiment. The control circuit 1, the acceleration sensor 2, the temperature sensor 3, and the inverter circuit 8, which are components (parts) of the motor control unit 10, are arranged on the circuit board 50. Note that parts other than those shown in Fig. 2 shown are different.

[0027] The control circuit 1, the acceleration sensor 2, the temperature sensor 3, and the inverter circuit 8 are mounted on the circuit board 50. Therefore, although the distance between the temperature sensor 3 and the inverter circuit 8 remains constant, the positional relationship between the temperature sensor 3 and the inverter circuit 8 changes depending on the position of the circuit board 50.

[0028] The circuit board 50 according to the present embodiment is arranged in a device with a motor, such as a robot arm or an air conditioner, without being housed in a casing. The circuit board 50 is fixed to a specific element at various positions within the device. This means that the circuit board 50 is arranged in an arbitrary position within the device. Even in a case where the circuit board 50 is fixed to the specific element at an arbitrary position, the motor control unit 10 controls the amount of power supplied to the motor 20 based on the position information.

[0029] In a case where the circuit board 50 is attached to the specific element, there is a case where the position of the specific element in the device changes. This means that the circuit board 50 is arranged so that the position changes to an arbitrary position after installation. In this case, when the position of the specific element changes, the position of the circuit board 50 also changes. For example, in a case where the circuit board 50 is arranged in a robot arm, the position of the circuit board 50 changes according to an operation of the robot arm. This means that the positional relationship between the temperature sensor 3 and the inverter circuit 8 changes according to an operation of the device in which the circuit board 50 is arranged.Even in a case where the position of the circuit board 50 changes, the motor control device 10 in the present embodiment controls the power supply amount to the motor 20 based on the position information.

[0030] Fig. 3 is a diagram showing a configuration of a motor control system including the motor control device according to the embodiment. In the present example, a motor control system 60 is a robot arm. The motor control system 60 includes an arm portion 40, which is a movable portion, and a base portion 70 coupled to the arm portion 40. The arm portion 40 includes joint portions 41 to 43, shaft portions 51 to 53, and an end portion 55.

[0031] The shaft portion 51 is rotatably coupled to the base portion 70 via the joint portion 41. The shaft portion 52 is rotatably coupled to the shaft portion 51 via the joint portion 42. The shaft portion 53 is rotatably coupled to the shaft portion 52 via the joint portion 43. The end portion 55 is coupled to the shaft portion 53. A hand that grips a workpiece is provided at the end portion 55. Note that the joint portions 41 to 43 receive driving forces directly or indirectly via a speed reducer, a gear, or the like by driving the motor 20 (not shown) included in the motor control system 60, and operate the shaft portions 51 to 53.

[0032] The motor control system 60 can change a position by rotating the joint sections 41 to 43 and moving the end section 55 to various positions. The circuit board 50 is arranged in the arm section 40, which is a movable section. The circuit board 50 is arranged, for example, in the shaft sections 51 to 53. Note that the circuit board 50 may be arranged in the joint sections 41 to 43. The motor 20 is arranged, for example, in the joint sections 41 to 43. Note that the motor 20 may be arranged in the shaft sections 51 to 53.

[0033] The motor 20 is controlled by the motor control unit 10, which is arranged on the circuit board 50, and rotates the joint sections 41 to 43. The joint sections 41 to 43 rotate to move the shaft sections 51 to 53, and as a result, the posture of the circuit board 50 changes. This means that the position of the circuit board 50 changes according to the operation of the movable section. The motor control unit 10 controls the amount of power supplied to the motor 20 based on the position information corresponding to the position of the circuit board 50.

[0034] The motor control unit 10 is configured by the circuit board 50 on which the inverter circuit 8 is arranged, and is not housed in the casing. Even in a case where the motor control unit 10 is not housed in the casing in which a heat dissipation device such as a heat sink is arranged, or in a case where the installation position changes independently of the casing, it is possible to protect the motor control unit 10 from excessive heat generation because the motor control unit 10 can reduce the amount of power supplied to the motor 20 based on the position information.

[0035] Furthermore, because the engine control unit 10 is not arranged in the housing, it is possible to reduce its size, and therefore, the engine control unit 10 is arranged in various positions in the engine control system 60. Even in this case, it is possible to protect the engine control unit 10 from excessive heat generation because the engine control unit 10 can reduce the amount of power supplied to the motor 20 based on the position information.

[0036] Furthermore, because the temperature sensor 3 is arranged on the circuit board 50 in the engine control unit 10, it is possible for the temperature sensor 3 to directly monitor the temperature on the circuit board 50 on which the parts are mounted. This makes it possible in the engine control unit 10 to reduce an error between the temperature of the part to be detected and the temperature detected by the temperature sensor 3.

[0037] Now, a hardware configuration of the control circuit 1 is described. Fig. 4 is a diagram showing an example of a hardware configuration for implementing the control circuit included in the engine control device according to the embodiment. The control circuit 1 can be implemented by an input device 300, a processor 100, a memory 200, and an output device 400. The processor 100 is, for example, a central processing unit (CPU) (also referred to as a central processing unit, central processing device, processing device, arithmetic device, microprocessor, microcomputer, and digital signal processor (DSP)) or a large-scale integration (LSI) system. The memory 200 is, for example, a random access memory (RAM) and a read-only memory (ROM).

[0038] The control circuit 1 is implemented by the processor 100, which reads and executes a control program stored in the memory 200, which can be executed by a computer, to perform an operation of the control circuit 1. It can be said that the control program, which is a program for executing the operation of the control circuit 1, causes the computer to execute a procedure or method of the control circuit 1.

[0039] The control program executed by the control circuit 1 has a modular configuration including the installation orientation calculation unit 4, the temperature calculation unit 5, and the heat generation determination unit 7, and the installation orientation calculation unit 4, the temperature calculation unit 5, and the heat generation determination unit 7 are loaded onto a main storage device, and the installation orientation calculation unit 4, the temperature calculation unit 5, and the heat generation determination unit 7 are created in the main storage device.

[0040] The input device 300 receives the acceleration information from the acceleration sensor 2 and sends the acceleration information to the processor 100. Furthermore, the input device 300 receives the detected temperature from the temperature sensor 3 and sends the detected temperature to the processor 100.

[0041] The memory 200 stores the restriction information 9 or the like. The restriction information 9 is read from the memory 200 by the processor 100. Furthermore, the memory 200 is used as a temporary storage when the processor 100 executes various types of processing. The output device 400 sends the power supply command to the inverter circuit 8.

[0042] The control program may be stored on a computer-readable storage medium in a file in an installable format or an executable format and provided as a computer program product. Furthermore, the control program of the control circuit 1 may be provided via a network, such as the Internet. Note that some of the functions of the control circuit 1 may be implemented by dedicated hardware, such as a dedicated circuit, and some may be implemented by software or firmware.

[0043] In this way, according to the embodiment, the motor controller 10 outputs the power supply command to the inverter circuit 8 based on the temperature threshold (limitation information 9) set for each item of position information, the position information, and the temperature information. As a result, the motor controller 10 can control the motor depending on the precise heat generation state of the part mounted on the circuit board 50.

[0044] The configurations shown in the above embodiment provide an example and can be combined with other known techniques. Furthermore, the configurations shown in the embodiment may be partially omitted or changed without departing from the scope. List of reference symbols 1 control circuit; 2 acceleration sensor; 3 temperature sensor; 4 Installation orientation calculation unit; 5 Temperature calculation unit; 6 Restriction information storage unit; 7 Heat generation determination unit; 8 inverter circuit; 9 Restrictions information; 10 Engine control unit; 20 engine; 40 arm section; 41 to 43 joint section; 50 circuit boards; 51 to 53 shaft section; 55 final section; 60 Engine control system; 70 base section; 100 processor; 200 storage; 300 input device; 400 output device.

Claims

[1] Engine control unit (10), comprising: an acceleration sensor (2) arranged on a circuit board (50), which detects an acceleration as a function of a position of the circuit board (50) and outputs the detected acceleration as acceleration information; a temperature sensor (3) arranged on the circuit board (50), which detects a temperature on the circuit board (50) and outputs the detected temperature as a detected temperature; an inverter circuit (8) arranged on the circuit board (50) which drives a motor (20); and a control circuit (1) arranged on the circuit board (50), which calculates position information indicating the position of the circuit board (50) based on the acceleration information, calculates temperature information indicating a temperature of a part arranged on the circuit board (50) based on the detected temperature, and controls the inverter circuit (8) by outputting a power supply command for the motor (20) to the inverter circuit (8), which power supply command is based on a temperature threshold value set for each item of the position information, the position information, and the temperature information. [2] The engine control device (10) according to claim 1, wherein the temperature threshold is set based on an arrangement relationship between the part and the temperature sensor (3). [3] Engine control unit (10) according to claim 1 or 2, wherein the temperature threshold comprises a first temperature threshold and a second temperature threshold which is greater than the first temperature threshold, and the control circuit (1) outputs a command to reduce a power supply amount to the motor (20) to the inverter circuit (8) in a case where the temperature information exceeds the first temperature threshold, and the control circuit (1) outputs a command to stop the power supply to the motor (20) to the inverter circuit (8) in a case where the temperature information exceeds the second temperature threshold. [4] The motor control device (10) according to claim 3, wherein, in a case where the temperature information exceeds the first temperature threshold and the temperature information does not exceed the second temperature threshold, the control circuit (1) outputs a command to reduce a power supply amount to the motor (20) to the inverter circuit (8), the reduction being greater the higher the temperature indicated by the temperature information is. [5] Engine control unit (10) according to one of claims 1 to 4, wherein the part is the inverter circuit (8). [6] Engine control device (10) according to one of claims 1 to 5, wherein the circuit board (50) is arranged in a movable portion (40) of a device comprising the engine (20) and the position changes according to an operation of the movable portion (40). [7] Engine control system (60) comprising: the engine control unit (10) according to claim 6; and the movable section (40).

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