Drive control device
By positioning the third microcontroller to overlap with the first and second microcontrollers on a circuit board, the drive control device optimizes wiring distances and noise resistance, ensuring redundant control and reduced noise immunity.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- ASTEMO LTD
- Filing Date
- 2024-02-15
- Publication Date
- 2026-05-21
AI Technical Summary
Conventional drive control devices lack consideration for the arrangement of CPUs, leading to increased wiring distances and reduced noise resistance, particularly when CPUs are arranged in parallel with centers on the same straight line.
The arrangement of microcontrollers on a circuit board positions the center of the third microcontroller on one side of a virtual line connecting the centers of the first and second microcontrollers, with at least a part of the third microcontroller overlapping one of the first or second microcontrollers, optimizing the wiring distances and reducing noise immunity.
This configuration suppresses the decrease in noise immunity by shortening wiring distances and balancing the distances between microcontrollers, maintaining redundant control even in the event of failure.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to a drive control device.
Background Art
[0002] As a conventional drive control device, for example, the one described in Patent Document 1 below is known.
[0003] Briefly explained, this drive control device has three CPUs (microcontrollers), and is a so-called redundant drive control device that can drive and control two systems of motors using two of the three CPUs.
Prior Art Documents
Patent Documents
[0004]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0005] However, in the conventional drive control device, no consideration is given to the arrangement of the three CPUs. For this reason, for example, as shown in the patent document, when the three CPUs are arranged in parallel such that the centers of the three CPUs are located on the same straight line, the wiring distance between the CPU arranged in the center and each of the CPUs arranged on both ends is longer than the wiring distance between the CPUs arranged on both ends. As a result, there is room for improvement in that the noise resistance of the drive control device is reduced.
[0006] Therefore, the present invention has been devised in view of the technical problems of the conventional drive control device, and an object thereof is to provide a drive control device capable of suppressing a decrease in noise resistance.
Means for Solving the Problems
[0007] In one aspect of the present invention, the center of the third microcontroller is positioned on one side of a virtual line connecting the centers of the first microcontroller and the centers of the second microcontroller, and in a view in a direction perpendicular to the virtual line in the horizontal direction of the circuit board, at least a part of the third microcontroller is positioned to overlap with at least one of the first microcontroller and the second microcontroller. [Effects of the Invention]
[0008] According to the present invention, the decrease in noise immunity can be suppressed. [Brief explanation of the drawing]
[0009] [Figure 1] This is a block diagram showing the system configuration of the drive control device according to the present invention. [Figure 2] This is a plan view of a circuit board in a first embodiment of the drive control device according to the present invention. [Figure 3] This is a schematic diagram of a circuit board showing the main parts of the first embodiment of the present invention. [Figure 4] This diagram shows another example of the first embodiment of the present invention, illustrating variations in the arrangement (layout) of the microcontroller on the circuit board. [Figure 5] This is a schematic diagram of a circuit board according to a modified example of the first embodiment of the present invention. [Figure 6] This is a schematic diagram of a circuit board showing the main parts of a second embodiment of the present invention. [Figure 7] This is a schematic diagram of a circuit board showing the main parts of a third embodiment of the present invention. [Figure 8] This is a schematic diagram of a circuit board showing the main parts of a fourth embodiment of the present invention, where (a) is a plan view and (b) is a cross-sectional view taken along line AA in Figure (a). [Figure 9] This is a schematic diagram of a circuit board according to a modified example of the fourth embodiment of the present invention, where (a) is a plan view and (b) is a cross-sectional view taken along line BB in Figure (a). [Modes for carrying out the invention]
[0010] Embodiments of the drive control device according to the present invention will be described in detail below with reference to the drawings. In the following embodiments, an example will be described in which the drive control device according to the present invention is applied to an ECU for the steering system of an automobile.
[0011] [First Embodiment] Figure 1 shows a block diagram illustrating the system configuration of a steering system to which the drive control device (the first drive control device DA1, described later) according to this embodiment is applied.
[0012] As shown in Figure 1, the steering system ST is configured using a so-called steer-by-wire system in which the steering wheel (not shown) and the steering wheels (not shown) are not mechanically connected. Specifically, the steering system ST is equipped with a triple redundant system and includes three steering angle sensors, namely the first, second, and third steering angle sensors AS1, AS2, and AS3; a first drive control device DA1 that generates a steering force on the steering wheels (not shown) based on the steering angles input to each steering angle sensor AS1, AS2, and AS3; and a second drive control device DA2 that generates a reaction force on the steering wheel (not shown) side that provides steering resistance based on the steering angles input to each steering angle sensor AS1, AS2, and AS3.
[0013] The first drive control device DA1 includes two steering motors, the first and second steering motors SM1 and SM2, and three microprocessors (microcontrollers) that constitute a triple-redundancy control system, namely the first, second, and third microcontrollers MP11, MP12, and MP13, and the first, second, and third inverters IV11, IV12, and IV13.
[0014] Among the first, second, and third microcontrollers MP11, MP12, and MP13 that constitute a triple control system, the first and second microcontrollers MP11 and MP12 each constitute a main system, and the third microcontroller MP13 constitutes a backup system. That is, the first microcontroller MP11 drives and controls the first steering motor SM1 via the first inverter IV11. Similarly, the second microcontroller MP12 drives and controls the second steering motor SM2 via the second inverter IV12. When the first microcontroller MP1 or the second microcontroller MP2 fails, the third microcontroller MP13 drives and controls the first steering motor SM1 or the second steering motor SM2 via the third inverter IV13.
[0015] Also, the first steering angle θ1 detected by the first steering angle sensor AS1 is input to the first microcontroller MP11 via the first CAN driver CD11. Similarly, the second steering angle θ2 detected by the second steering angle sensor AS2 is input to the second microcontroller MP12 via the second CAN driver CD12. On the other hand, the third steering angle θ3 detected by the third steering angle sensor AS3 is directly input to the third microcontroller MP3.
[0016] The first inverter IV11 is connected to the first steering motor SM1 via the first relay RL11. Similarly, the second inverter IV12 is connected to the second steering motor SM2 via the second relay RL12. On the other hand, the third inverter IV13 is connected to the first steering motor SM1 via the first third relay RL31 and is also connected to the second steering motor SM2 via the second third relay RL32.
[0017] The second drive control device DA2 includes the first and second reaction motors SR1 and SR2, which are two systems of reaction motors, and the first and second microcontrollers MP21 and MP22 and the first and second inverters IV21 and IV22, which are two microprocessors (microcontrollers) that constitute a dual control system.
[0018] The first microcomputer MP21 drives and controls the first reaction force motor SR1 via the first inverter IV21. The first inverter IV21 is connected to the first reaction force motor SR1 via the first relay RL21. Similarly, the second microcomputer MP22 drives and controls the second reaction force motor SR2 via the second inverter IV22. The second inverter IV22 is connected to the second reaction force motor SR2 via the second relay RL22.
[0019] In addition, the first steering angle θ1 detected by the first steering angle sensor AS1 is input to the first microcomputer MP21 via the first CAN driver CD21. Similarly, the second steering angle θ2 detected by the second steering angle sensor AS2 is input to the second microcomputer MP22 via the second CAN driver CD22. The first CAN driver CD21 of the second drive control device DA2 and the first CAN driver CD11 of the first drive control device DA1, and the second CAN driver CD22 and the second CAN driver CD12 can communicate with each other.
[0020] (Configuration of Drive Control Device) FIG. 2 shows a plan view of a circuit board constituting the first drive control device DA1.
[0021] The first drive control device DA1 is configured by housing a circuit board 1 having a generally rectangular shape shown in FIG. 2 inside a housing not shown. The circuit board 1 is fixed to the housing not shown via fastening members (such as screws) passing through six mounting holes 100 arranged at the outer peripheral edge of the circuit board 1 inside the housing not shown. Here, the circuit board of the first drive control device DA1 can be constituted by a single or a plurality of circuit boards. In the present embodiment, the first drive control device DA1 is constituted by a plurality of circuit boards, and the circuit board 1 shown in FIG. 2 is one of the plurality of circuit boards constituting the first drive control device DA1. The circuit board 1 is connected to other circuit boards not shown via a harness not shown that is inserted into a connector CN described later.
[0022] Specifically, the circuit board 1 has a first mounting surface 11 on its surface as shown in Figure 2, and an electronic circuit (pattern) not shown is formed on this first mounting surface 11, flowing from left to right in Figure 2. The first mounting surface 11 mainly has three microcontrollers, the first, second, and third microcontrollers MP11, MP12, and MP13, three power supply elements (power supply ICs), the first, second, and third power supply elements PS1, PS2, and PS3, and three pre-drivers, the first, second, and third pre-drivers PD11, PD12, and PD13. In addition, a connector CN, which is a BtoB connector used for connecting to other circuit boards not shown, is provided at one end in the longitudinal direction of the first mounting surface 11 of the circuit board 1 (the right end in Figure 2). Other components such as multiple coils 21, multiple test connectors 22, multiple diodes 23, and multiple electrolytic capacitors 24 are mounted on the mounting surface of the circuit board 1.
[0023] The first, second, and third microcontrollers MP11, MP12, and MP13 form a triple-redundant system, with the first and second microcontrollers MP11 and MP12 forming the main system and the third microcontroller MP13 forming the backup system. Therefore, when the first and second microcontrollers MP11 and MP12 are operating normally, they calculate the first and second drive torques T1 and T2 based on the first and second steering angles θ1 and θ2 detected by the first and second steering angle sensors AS1 and AS2 (see Figure 1). On the other hand, if either of the first or second microcontrollers MP11 or MP12 fails, the third microcontroller MP13 calculates the first drive torque T1 or second drive torque T2 based on the first steering angle θ1 or second steering angle θ2, as a substitute for the failed first or second microcontroller MP11 or second microcontroller MP12.
[0024] Furthermore, on circuit board 1, the first central arithmetic circuit CC1 is formed by including the first microcontroller MP11 and peripheral electronic components such as chip capacitors and chip resistors. Similarly, on circuit board 1, the second central arithmetic circuit CC2 is formed by including the second microcontroller MP12 and peripheral electronic components such as chip capacitors and chip resistors. In addition, on circuit board 1, the third central arithmetic circuit CC3 is formed by including the third microcontroller MP13 and peripheral electronic components such as chip capacitors and chip resistors.
[0025] The first power supply element PS1 supplies driving power to the first microcontroller MP11. The first power supply circuit PC1 is formed by the first power supply element PS1 and peripheral electronic components such as chip capacitors and chip resistors. Similarly, the second power supply element PS2 supplies driving power to the second microcontroller MP12. The second power supply circuit PC2 is formed by the second power supply element PS2 and peripheral electronic components such as chip capacitors and chip resistors. Furthermore, the third power supply element PS3 supplies driving power to the third microcontroller MP13. The third power supply circuit PC3 is formed by the third power supply element PS3 and peripheral electronic components such as chip capacitors and chip resistors.
[0026] The first pre-driver PD11 drives and controls the first steering motor SM1 based on the first drive torque T1 calculated by the first microcontroller MP11. The first input circuit DC1 is formed by the first pre-driver PD11 and peripheral electronic components such as chip capacitors and chip resistors. Similarly, the second pre-driver PD12 drives and controls the second steering motor SM2 based on the second drive torque T2 calculated by the second microcontroller MP12. The second input circuit DC2 is formed by the second pre-driver PD12 and peripheral electronic components such as chip capacitors and chip resistors. Furthermore, the third pre-driver PD13 drives and controls either the first steering motor SM1 or the second steering motor SM2 based on the first drive torque T1 or second drive torque T2 calculated by the third microcontroller MP13. The third input circuit DC3 is formed by the third pre-driver PD13 and peripheral electronic components such as chip capacitors and chip resistors.
[0027] Figure 3 is a diagram showing a characteristic configuration of this embodiment, and is a schematic diagram showing the positional relationship (layout) of the first, second, and third microcontrollers MP11, MP12, MP13 and the first, second, and third power supply elements PS1, PS2, PS3 on the first mounting surface 11 of the circuit board 1. Figure 4 is a schematic diagram showing a modified arrangement (layout) of the first, second, and third microcontrollers MP11, MP12, MP13 on the first mounting surface 11 of the circuit board 1.
[0028] As shown in Figure 3, on the circuit board 1, the first microcontroller MP11 and the second microcontroller MP12, which constitute the main system among the first, second, and third microcontrollers MP11, MP12, and MP13, are arranged in a so-called mirroring state, facing each other in a direction perpendicular to the longitudinal direction of the circuit board 1 (the vertical direction in Figure 3). Furthermore, the first microcontroller MP11 and the second microcontroller MP12 are arranged in close proximity with a distance C1 shorter than one side OS or diagonal DG of the outer shape of the third microcontroller MP13 in a plan view of the circuit board 1.
[0029] Furthermore, on circuit board 1, among the first, second, and third microcontrollers MP11, MP12, and MP13, the third microcontroller MP13, which constitutes the backup system, is positioned downstream of the first and second microcontrollers MP11 and MP12, that is, on the pre-driver (first, second, and third pre-driver PD11, PD12, PD13) side of the virtual line VL that connects the center G1 of the first microcontroller MP11 and the center G2 of the second microcontroller MP12. In addition, the third microcontroller MP13 is positioned such that, when viewed from a direction perpendicular to the virtual line VL in the horizontal direction of circuit board 1, a part of the third microcontroller MP13 overlaps with at least one of the first and second microcontrollers MP11 and MP12.
[0030] Here, as shown in Figure 3, it is desirable that the center G3 of the third microcontroller MP13 is located between the center G1 of the first microcontroller MP11 and the center G2 of the second microcontroller MP12 (GS12) in a plan view of the circuit board 1. More preferably, it is desirable that the third microcontroller MP13 is located such that its center G3 is equidistant from the centers G1 and G2 of the first and second microcontrollers MP11 and MP12, respectively; that is, the distance GS13 between the first microcontroller MP11 and the third microcontroller MP13 is equal to the distance GS23 between the second microcontroller MP12 and the third microcontroller MP13.
[0031] Furthermore, the above-mentioned statement, "The third microcontroller MP13 is positioned such that, when viewed from a direction perpendicular to the virtual line VL in the horizontal direction of the circuit board 1, a part of the third microcontroller MP13 overlaps with at least one of the first and second microcontrollers MP11 and MP12," includes not only the configuration shown in Figure 3, where one side OS of the first, second, and third microcontrollers MP11, MP12, and MP13 is parallel or perpendicular to the virtual line VL, but also, for example, the configuration shown in Figure 4(a), where the diagonal DG of the first, second, and third microcontrollers MP11, MP12, and MP13 is parallel to the virtual line VL.
[0032] Furthermore, since the third microcontroller MP13 constitutes the backup system, it may be formed to a different size from the first and second microcontrollers MP11 and MP12, which are arranged in a mirroring state to constitute the main system, as shown in Figures 4(b) and 4(c). In this case, as shown in Figure 4(d), for example, the first and second microcontrollers MP11 and MP12 may be arranged so that one side OS is parallel or perpendicular to the virtual line VL, while the third microcontroller MP13 may be arranged so that its diagonal DG is parallel to the virtual line VL, with the orientation of the first and second microcontrollers MP11 and MP12 and the third microcontroller MP13 being different.
[0033] Furthermore, in this embodiment, on the circuit board 1, the third microcontroller MP13 is positioned close to the first and second microcontrollers MP11 and MP12 with a distance C2 that is smaller than the distance C1 between the first microcontroller MP11 and the second microcontroller MP12.
[0034] Furthermore, the first, second, and third power supply elements PS1, PS2, and PS3 are arranged on the circuit board 1 so as to be upstream of the first, second, and third microcontrollers MP11, MP12, and MP13, that is, on the opposite side of the pre-drivers (first, second, and third pre-drivers PD11, PD12, and PD13) across the virtual line VL. In this embodiment, the first, second, and third power supply elements PS1, PS2, and PS3 are arranged in parallel at roughly equal intervals along the vertical direction of the circuit board 1, that is, in a direction parallel to the virtual line VL. In addition, the first, second, and third power supply elements PS1, PS2, and PS3 are arranged in a mirroring state with the first power supply element PS1 and the second power supply element PS2 at their respective ends, and the third power supply element PS3 is arranged between the first power supply element PS1 and the second power supply element PS2.
[0035] (Effects of this embodiment) The conventional drive control device described above does not consider the arrangement (layout) of the three CPUs, the first, second, and third microcontrollers. For example, if the first, second, and third microcontrollers are arranged in parallel so that their centers are on the same straight line, as shown in the aforementioned patent document, the wiring distance between the first and second microcontrollers located on either end becomes longer than the wiring distance between the third microcontroller located in the center and the first and second microcontrollers located on either end. This reduces the noise immunity of the drive control device, and there was room for improvement.
[0036] In contrast, the first drive control device DA1 according to this embodiment is a drive control device having at least three drive systems that supply drive power to the windings of electric motors (first and second steering motors SM1 and SM2), wherein the first drive system, second drive system, and third drive system constituting the three drive systems have a first microcontroller MP11, a second microcontroller MP12, and a third microcontroller MP13 on a circuit board 1, with a rectangular shape in plan view, the first drive system is driven and controlled by the first microcontroller MP11, the second drive system is driven and controlled by the second microcontroller MP12, and the third drive system is driven and controlled by the third microcontroller MP13 Driven and controlled by [unclear], the first microcontroller MP11 and the second microcontroller MP12 are positioned closer together than the dimension of one side OS or diagonal DG of the outer shape of the third microcontroller MP13 in a plan view of the circuit board 1, with the center G3 of the third microcontroller MP13 positioned to one side of the imaginary line VL connecting the center G1 of the first microcontroller MP11 and the center G2 of the second microcontroller MP12, and when viewed from a direction perpendicular to the imaginary line VL in the horizontal direction of the circuit board 1, at least a part of the third microcontroller MP13 is positioned to overlap with at least one of the first microcontroller MP11 and the second microcontroller MP12.
[0037] Thus, in the first drive control device DA1 according to this embodiment, the center G3 of the third microcontroller MP13 is positioned on one side of the imaginary line VL connecting the center G1 of the first microcontroller MP11 and the center G2 of the second microcontroller MP12. When viewed from a direction perpendicular to the imaginary line VL in the horizontal direction of the circuit board 1, at least a part of the third microcontroller MP13 is positioned to overlap with at least one of the first microcontroller MP11 and the second microcontroller MP12. Therefore, the wiring distance between the first microcontroller MP11 and the second microcontroller MP12, the wiring distance between the first microcontroller MP11 and the third microcontroller MP13, and the wiring distance between the second microcontroller MP12 and the third microcontroller MP13 can all be shortened. In other words, in addition to the wiring distance between the first and second microcontrollers MP11 and MP12 and the third microcontroller MP13, the wiring distance between the first microcontroller MP11 and the second microcontroller MP12 can also be shortened. This makes it possible to suppress the decrease in noise immunity of the first drive control device DA1.
[0038] Furthermore, in this embodiment, the first drive system and the second drive system are main systems that primarily drive and control the electric motors (first and second steering motors SM1 and SM2), while the third drive system is a backup system that functions as an alternative in the event of failure of the first or second drive system.
[0039] Thus, according to this embodiment, even if either the first drive system or the second drive system fails, the backup system, the third drive system, can replace the failed drive system among the first and second drive systems, thereby maintaining redundant control that drives the two electric motors (first and second steering motors SM1 and SM2).
[0040] Furthermore, in this embodiment, when viewed from a direction perpendicular to the virtual line VL in the horizontal direction of the circuit board 1, the center G3 of the third microcontroller MP13 is positioned between the center G1 of the first microcontroller MP11 and the center G2 of the second microcontroller MP12.
[0041] According to the present invention, the center G3 of the third microcontroller MP13 is positioned between the center G1 of the first microcontroller MP11 and the center G2 of the second microcontroller MP12. This reduces the imbalance in the distances between each microcontroller MP11, MP12, and MP13, and suppresses the functional differences caused by this imbalance.
[0042] Furthermore, in this embodiment in particular, the first microcontroller MP11, the second microcontroller MP12, and the third microcontroller MP13 are arranged at equal distances from each other.
[0043] Thus, in particular, according to this embodiment, the first microcontroller MP11, the second microcontroller MP12, and the third microcontroller MP13 are arranged at equal distances from each other. This optimizes the distance between each microcontroller MP11, MP12, and MP13, and suppresses functional differences caused by imbalances in the distances between each microcontroller MP11, MP12, and MP13.
[0044] (modified version) Figure 5 shows a modified example of the first embodiment of the drive control device according to the present invention, and is a schematic diagram showing the positional relationship (layout) between the first, second, and third microcontrollers MP11, MP12, MP13 and the first, second, and third power supply elements PS1, PS2, PS3 on the first mounting surface 11 of the circuit board 1.
[0045] As shown in Figure 5, in the modified first drive control device DA1, the third microcontroller MP13 is positioned so as to be greater than the distance (spacing C1) between the first microcontroller MP11 and the second microcontroller MP12, and closer than the dimension of one side OS or diagonal DG of the outer shape of the third microcontroller MP13.
[0046] Thus, in this embodiment, the third microcontroller MP13 is positioned at a distance (spacing C2) greater than the distance (spacing C1) between the first and second microcontrollers MP11 and MP12. This makes it possible to suppress the thermal influence of the third microcontroller MP13 on the first and second microcontrollers MP11 and MP12.
[0047] [Second Embodiment] Figure 6 shows a second embodiment of the drive control device according to the present invention. This embodiment is a modification of the arrangement of the third power supply element PS3 compared to the first embodiment, and the other configurations are the same as those of the first embodiment. Therefore, the same reference numerals are used for components that are the same as those of the first embodiment, and their descriptions are omitted.
[0048] (Configuration of the drive control system) Figure 6 is a diagram showing a characteristic configuration of this embodiment, and is a schematic diagram showing the positional relationship (layout) of the first, second, and third microcontrollers MP11, MP12, MP13 and the first, second, and third power supply elements PS1, PS2, PS3 on the first mounting surface 11 of the circuit board 1.
[0049] As shown in Figure 6, in the first drive control device DA1 according to this embodiment, in a plan view of the first mounting surface 11 of the circuit board 1, the third power supply element PS3 is arranged in parallel along a direction that is roughly parallel to the virtual line VL, above the third microcontroller MP13. In other words, in this embodiment, the first power supply element PS1 is arranged downstream of the first and second microcontrollers MP11 and MP12, that is, on the pre-driver (first, second, and third pre-drivers PD11, PD12, PD13) side of the virtual line VL.
[0050] (Effects of this embodiment) As described above, in the first drive control device DA1 according to this embodiment, the first drive system includes a first power supply element PS1 that supplies power to the first microcontroller MP11 and a first pre-driver PD11 that drives electric motors (first and second steering motors SM1 and SM2) based on control signals from the first microcontroller MP11; the second drive system includes a second power supply element PS2 that supplies power to the second microcontroller MP12 and a second pre-driver PD12 that drives electric motors (first and second steering motors SM1 and SM2) based on control signals from the second microcontroller MP12; and the third drive system includes a third power supply element PS3 that supplies power to the third microcontroller MP13 and a third pre-driver that drives electric motors (first and second steering motors SM1 and SM2) based on control signals from the third microcontroller MP13. The system includes a pre-driver PD13, and the electric motors (first and second steering motors SM1 and SM2) are driven by the respective pre-drivers PD11, PD12, and PD13 based on control signals from the first microcontroller MP11, the second microcontroller MP12, or the third microcontroller MP13. The first pre-driver PD11, the second pre-driver PD12, and the third pre-driver PD13 are arranged on the opposite side of the third microcontroller MP13 from the first microcontroller MP11 and the second microcontroller MP12. The first power supply element PS1 and the second power supply element PS2 are arranged on the opposite side of the first microcontroller MP11 and the second microcontroller MP12 from the respective pre-drivers PD11, PD12, and PD13. The third microcontroller MP13 and the third power supply element PS3 are arranged in parallel with the first microcontroller MP11 and the second microcontroller MP12.
[0051] Thus, in this embodiment, since the third microcontroller MP13 and the third power supply element PS3 are arranged in parallel with the first microcontroller MP11 and the second microcontroller MP12, there is no risk that the wiring connecting the third power supply element PS3 and the third microcontroller MP13 will pass between the first and second microcontrollers MP11 and MP12. As a result, the influence of noise generated by the power supply from the third power supply element PS3 to the third microcontroller MP13 passing between the first and second microcontrollers MP11 and MP12 can be suppressed.
[0052] Furthermore, in this embodiment, the first power supply element PS1 and the second power supply element PS2 are positioned on the opposite side of the first microcontroller MP11 and the second microcontroller MP12 from the respective pre-drivers (first, second, and third pre-drivers PD11, PD12, and PD13), while the third microcontroller MP13 and the third power supply element PS3 are positioned closer to the respective pre-drivers (first, second, and third pre-drivers PD11, PD12, and PD13) than the first microcontroller MP11 and the second microcontroller MP12. As a result, the third power supply element PS3 is positioned at a distance from the first and second power supply elements PS1 and PS2, thereby suppressing the thermal influence of the third power supply element PS3 on the first and second power supply elements PS1 and PS2.
[0053] Furthermore, in this embodiment, the third power supply element PS3 and the third microcontroller MP13 are arranged on the side of each pre-driver (first, second, and third pre-drivers PD11, PD12, PD13) with the first and second microcontrollers MP11 and MP12 in between. Therefore, even if the third microcontroller MP13 and the third power supply element PS3 are not arranged in parallel with the first microcontroller MP11 and the second microcontroller MP12, there is no risk that the wiring connecting the third power supply element PS3 and the third microcontroller MP13 will pass between the first and second microcontrollers MP12 and MP13. This makes it possible to suppress the effects of noise generated by the power supply from the third power supply element PS3 to the third microcontroller MP13 passing between the first and second microcontrollers MP11 and MP12.
[0054] In other words, by arranging the third power supply element PS3 and the third microcontroller MP13 on the side of each pre-driver (first, second, and third pre-drivers PD11, PD12, PD13) with the first and second microcontrollers MP11 and MP12 in between, the effects of noise generated by the power supply from the third power supply element PS3 to the third microcontroller MP13 passing between the first and second microcontrollers MP11 and MP12 can be suppressed, even without arranging the third microcontroller MP13 and the third power supply element PS3 in parallel with the first microcontroller MP11 and the second microcontroller MP12.
[0055] [Third Embodiment] Figure 7 shows a third embodiment of the drive control device according to the present invention. This embodiment is a modification of the arrangement of the third power supply element PS3 and the third microcontroller MP13 in the first embodiment, and the other configurations are the same as in the first embodiment. Therefore, the same reference numerals are used for components that are the same as in the first embodiment, and their descriptions are omitted.
[0056] (Configuration of the drive control system) Figure 7 is a diagram showing a characteristic configuration of this embodiment, and is a schematic diagram showing the positional relationship (layout) of the first, second, and third microcontrollers MP11, MP12, MP13 and the first, second, and third power supply elements PS1, PS2, PS3 on the first mounting surface 11 of the circuit board 1.
[0057] As shown in Figure 7, in the first drive control device DA1 according to this embodiment, the third microcontroller MP13 is located upstream of the first and second microcontrollers MP11 and MP12 on the first mounting surface 11 of the circuit board 1, that is, on the side of the first and second power supply elements PS1 and PS2 relative to the virtual line VL. Furthermore, on the first mounting surface 11, the third power supply element PS3 is located not between the first and second power supply elements PS1 and PS2, but above the third microcontroller MP13, that is, in parallel along a direction roughly parallel to the virtual line VL.
[0058] (Effects of this embodiment) As described above, in the first drive control device DA1 according to this embodiment, the third microcontroller MP13 and the third power supply element PS3 are arranged in parallel with the first microcontroller MP11 and the second microcontroller MP12.
[0059] Thus, in this embodiment, similar to the second embodiment, the third microcontroller MP13 and the third power supply element PS3 are arranged in parallel with the first microcontroller MP11 and the second microcontroller MP12, eliminating the risk of the wiring connecting the third power supply element PS3 and the third microcontroller MP13 passing between the first and second microcontrollers MP11 and MP12. This makes it possible to suppress the effects of noise generated by the power supply from the third power supply element PS3 to the third microcontroller MP13 passing between the first and second microcontrollers MP11 and MP12.
[0060] Furthermore, in this embodiment, the third microcontroller MP13 and the third power supply element PS3 are arranged between the first microcontroller MP11 and the second microcontroller MP12, and the first power supply element PS1 and the second power supply element PS2.
[0061] Therefore, even if the third microcontroller MP13 and the third power supply element PS3 are not arranged in parallel with the first microcontroller MP11 and the second microcontroller MP12, there is no risk that the wiring connecting the third power supply element PS3 and the third microcontroller MP13 will pass between the first and second microcontrollers MP11 and MP12. This makes it possible to suppress the effects of noise generated by the power supply from the third power supply element PS3 to the third microcontroller MP13 passing between the first and second microcontrollers MP11 and MP12.
[0062] [Fourth Embodiment] Figure 8 shows a fourth embodiment of the drive control device according to the present invention. This embodiment is a modification of the arrangement of the third power supply element PS3 and the third microcontroller MP13 in the first embodiment, and the other configurations are the same as in the first embodiment. Therefore, the same reference numerals are used for components that are the same as in the first embodiment, and their descriptions are omitted.
[0063] (Configuration of the drive control system) Figure 8 shows the main parts of the first drive control device DA1 according to the fourth embodiment of the present invention, where (a) is a schematic diagram showing the positional relationship (layout) of the first and second microcontrollers MP11, MP12 and the first, second, and third power supply elements PS1, PS2, PS3 on the first mounting surface 11 of the circuit board 1, and (b) is a cross-sectional view taken along line AA of Figure (a).
[0064] As shown in Figure 8, in the first drive control device DA1 according to this embodiment, the circuit board 1 has a first mounting surface 11 provided on the front surface as shown in Figure 8(b), and a second mounting surface 12 provided on the back surface. Two microcontrollers that constitute the main system, namely the first and second microcontrollers MP11 and MP12, and three power supply elements (power supply ICs), namely the first, second, and third power supply elements PS1, PS2, and PS3, are mounted on the first mounting surface 11. The positional relationship between the first and second microcontrollers MP11 and MP12 and the first, second, and third power supply elements PS1, PS2, and PS3 is the same as in the first embodiment described above.
[0065] On the other hand, a third microcontroller MP13 is mounted on the second mounting surface 12, which constitutes a backup system in case one of the first or second microcontrollers MP11 or MP12 fails. Similar to the first embodiment, the third microcontroller MP13 is located downstream of the first and second microcontrollers MP11 and MP12, that is, on the pre-driver (first, second, and third pre-drivers PD11, PD12, PD13) side of the virtual line VL that connects the center G1 of the first microcontroller MP11 and the center G2 of the second microcontroller MP12. Furthermore, when viewed from a direction perpendicular to the virtual line VL in the horizontal direction of the circuit board 1, a part of the third microcontroller MP13 is positioned to face at least one of the first or second microcontrollers MP11 or MP12 across the circuit board 1.
[0066] Here, as shown in Figure 8, it is desirable that the center G3 of the third microcontroller MP13 is located between the center G1 of the first microcontroller MP11 and the center G2 of the second microcontroller MP12 in a plan view of the circuit board 1. More preferably, it is desirable that the center G3 of the third microcontroller MP13 is located at an equidistant distance from the centers G1 and G2 of the first and second microcontrollers MP11 and MP12, respectively.
[0067] (Effects of this embodiment) As described above, in the first drive control device DA1 according to this embodiment, the circuit board 1 has a first mounting surface 11 provided on the front surface and a second mounting surface 12 provided on the back surface, the first microcontroller MP11 is arranged on the first mounting surface 11 and the second microcontroller MP12 or the third microcontroller MP13 is arranged on the second mounting surface 12.
[0068] Thus, according to this embodiment, the third microcontroller MP13 is positioned on the second mounting surface 12 of the circuit board 1, which is opposite to the first mounting surface 11 on which the first microcontroller MP11 is mounted. Therefore, the mounting area of the third microcontroller MP13 on the first mounting surface 11 of the circuit board 1 can be reduced by the amount of the third microcontroller MP13 positioned on the second mounting surface 12. This allows for miniaturization of the circuit board 1 and contributes to miniaturization of the first drive control device DA1.
[0069] Furthermore, in this embodiment, the third microcontroller MP13, which is located on the second mounting surface 12, is positioned such that it is partially offset in the planar direction of the circuit board 1 from the first microcontroller MP11, which is located on the first mounting surface 11.
[0070] Thus, in this embodiment, the third microcontroller MP13, which is located on the second mounting surface 12, is positioned such that it is offset by at least a portion of the first and second microcontrollers MP11 and MP12, which are located on the first mounting surface 11, in the planar direction of the circuit board 1. In other words, the third microcontroller MP13 is positioned so that it does not completely overlap with the first and second microcontrollers MP11 and MP12 in the planar direction of the circuit board 1. As a result, there is no risk of the wiring connected to the third microcontroller MP13 completely overlapping with the wiring connected to the first microcontroller MP11, and the layout of the wiring connected to each microcontroller MP11, MP12, and MP13 can be improved.
[0071] In particular, in this embodiment, the third microcontroller MP13 is positioned so as to be completely offset from the first and second microcontrollers MP11 and MP12 in the planar direction of the circuit board 1. This makes it possible to maximize the layout efficiency of the wiring connected to each of the microcontrollers MP11, MP12, and MP13.
[0072] (modified version) Figure 9 shows a modified example of the fourth embodiment of the drive control device according to the present invention, and is a schematic diagram showing the positional relationship (layout) between the first, second, and third microcontrollers MP11, MP12, MP13 and the first, second, and third power supply elements PS1, PS2, PS3 on the first mounting surface 11 of the circuit board 1. Specifically, Figure 9(a) is a schematic plan view of the first mounting surface 11 of the circuit board 1, and Figure 9(b) is a cross-sectional view taken along the BB line in Figure 9(a).
[0073] As shown in Figure 9, in the modified first drive control device DA1, a heat sink 25, which is a heat dissipation member for dissipating heat from the first and second microcontrollers MP11 and MP12, is positioned on the second mounting surface 12 opposite to the first mounting surface 11 on which the first and second microcontrollers MP11 and MP12 are mounted, in a position (region) that overlaps with the first and second microcontrollers MP11 and MP12 across the circuit board 1.
[0074] Furthermore, on the second mounting surface 12 of the circuit board 1, a portion of the third microcontroller MP13 is positioned so as to overlap with the first and second microcontrollers MP11 and MP12 across the circuit board 1 (see dashed line in Figure 9). In other words, a portion of the third microcontroller MP13 is positioned so as to overlap (oppose) the first and second microcontrollers MP11 and MP12 vertically across the circuit board 1 in the longitudinal direction of the circuit board 1.
[0075] On the other hand, on the first mounting surface 11, which is opposite to the second mounting surface 12 on which the third microcontroller MP13 is mounted, an electrolytic capacitor 24, which is a noise reduction component used to remove noise from the third microcontroller MP13, is placed in a position (region) that overlaps with the third microcontroller MP13 across the circuit board 1.
[0076] As described above, in the modified first drive control device DA1, a heat dissipation member for dissipating heat from the microcontrollers on one mounting surface, or a noise reduction component for removing noise from the microcontrollers on one mounting surface, is arranged on the other mounting surface opposite to the mounting surface on which at least one of the first microcontroller MP11, second microcontroller MP12, and third microcontroller MP13 is arranged.
[0077] As described above, in this modified version, a heat sink 25, which is a heat dissipation member for dissipating heat from the first and second microcontrollers MP11 and MP12 mounted on the first mounting surface 11, is placed on the second mounting surface 12 of the circuit board 1. This allows for effective dissipation of heat emitted from the first and second microcontrollers MP11 and MP12. On the other hand, an electrolytic capacitor 24, which is a noise reduction component for removing noise from the third microcontroller MP13 mounted on the second mounting surface 12, is placed on the first mounting surface 11 of the circuit board 1. This allows for effective removal of electromagnetic noise emitted from the third microcontroller MP13.
[0078] Furthermore, in this modified example, on the second mounting surface 12, a portion of the third microcontroller MP13 is arranged to overlap with the first and second microcontrollers MP11 and MP12, with the circuit board 1 in between. As a result, the overlap between the first and second microcontrollers MP11 and MP12 and the third microcontroller MP13 reduces the area of the circuit board 1 occupied by the third microcontroller MP13, particularly the length of the circuit board 1, thereby enabling miniaturization of the circuit board 1. This allows for miniaturization of the first drive control device DA1.
[0079] The present invention is not limited to the configurations disclosed in the embodiments described above, and can be freely modified according to, for example, the specifications of the drive control device to which the present invention is applied.
[0080] In particular, the present invention is characterized by the arrangement of the first, second, and third microcontrollers MP11, MP12, MP13 and the first, second, and third power supply elements PS1, PS2, PS3. Therefore, details of the configuration that are not directly related to this feature, such as the number of circuit boards 1 and the form of the circuit board 1, as well as peripheral electronic components mounted on the circuit board 1, can be arbitrarily changed according to the specifications of the drive control device to which the present invention is applied.
[0081] Furthermore, although the above embodiments illustrate the application of the present invention to a triple-redundant system, the present invention only requires three or more microcontrollers and power supply elements (power supply ICs), and can also be applied to quadruple-redundant or higher-redundant systems.
Claims
1. A drive control device having at least three drive systems that supply drive power to the windings of an electric motor, The first, second, and third drive systems, which constitute the three drive systems, each have a first microcontroller, a second microcontroller, and a third microcontroller on a circuit board, with a rectangular shape in plan view. The first drive system is driven and controlled by the first microcontroller. The second drive system is driven and controlled by the second microcontroller. The third drive system is driven and controlled by the third microcontroller. The first microcontroller and the second microcontroller are arranged in a plan view of the circuit board at a distance greater than the length of one side or diagonal of the outer shape of the third microcontroller. The center of the third microcontroller is located on one side of the imaginary line connecting the center of the first microcontroller and the center of the second microcontroller. When viewed from a direction perpendicular to the virtual line in the horizontal direction of the circuit board, at least a portion of the third microcontroller is arranged to overlap with at least one of the first microcontroller and the second microcontroller. A drive control device characterized by the following:
2. A drive control device according to claim 1, The first drive system and the second drive system are the main systems that primarily drive and control the electric motor. The third drive system is a backup system that functions as an alternative in the event that the first drive system or the second drive system fails. A drive control device characterized by the following:
3. A drive control device according to claim 2, The third microcontroller is positioned so as to be greater than the distance between the first and second microcontrollers, and closer than the dimension of one side or diagonal of the outer shape of the third microcontroller. A drive control device characterized by the following:
4. A drive control device according to claim 1, The first drive system includes a first power supply element that supplies power to the first microcontroller, and a first pre-driver that drives the electric motor based on a control signal from the first microcontroller. The second drive system includes a second power supply element that supplies power to the second microcontroller, and a second pre-driver that drives the electric motor based on a control signal from the second microcontroller. The third drive system includes a third power supply element that supplies power to the third microcontroller, and a third pre-driver that drives the electric motor based on a control signal from the third microcontroller. The electric motor is driven by the respective pre-drivers based on control signals from the first microcontroller, the second microcontroller, or the third microcontroller. The first pre-driver, the second pre-driver, and the third pre-driver are arranged on the opposite side of the third microcontroller from the first and second microcontrollers, The first power supply element and the second power supply element are arranged on the opposite side of the first microcontroller and the second microcontroller from the respective pre-drivers. The third microcontroller and the third power supply element are arranged in parallel with the first microcontroller and the second microcontroller. A drive control device characterized by the following:
5. A drive control device according to claim 4, The third microcontroller and the third power supply element are located on the pre-driver side of the first microcontroller and the second microcontroller, A drive control device characterized by the following:
6. A drive control device according to claim 4, The third microcontroller and the third power supply element are positioned between the first microcontroller and the second microcontroller and the first power supply element and the second power supply element. A drive control device characterized by the following:
7. A drive control device according to claim 1, When viewed from a direction perpendicular to the virtual line in the horizontal direction of the circuit board, the center of the third microcontroller is positioned between the center of the first microcontroller and the center of the second microcontroller. A drive control device characterized by the following:
8. A drive control device according to claim 7, The first microcontroller, the second microcontroller, and the third microcontroller are arranged at equal distances from each other. A drive control device characterized by the following:
9. A drive control device according to claim 1, The circuit board has a first mounting surface provided on the front surface and a second mounting surface provided on the back surface. The first microcontroller is located on the first mounting surface, The second microcontroller or the third microcontroller is located on the second mounting surface. A drive control device characterized by the following:
10. A drive control device according to claim 9, The second microcontroller or the third microcontroller, which is positioned on the second mounting surface, is positioned such that a portion of it is offset from the first microcontroller, which is positioned on the first mounting surface, in the planar direction of the circuit board. A drive control device characterized by the following:
11. A drive control device according to claim 10, On the mounting surface opposite to the mounting surface on which at least one of the first, second, and third microcontrollers is located, a heat dissipation member for dissipating heat from the microcontroller located on the mounting surface, or a noise reduction component for removing noise from the microcontroller located on the mounting surface, is located. A drive control device characterized by the following:
12. A drive control device according to claim 11, The first drive system and the second drive system are the main systems that primarily drive and control the electric motor. The third drive system is a backup system that functions as an alternative in the event that the first drive system or the second drive system fails. The second microcontroller or the third microcontroller located on the second mounting surface is the microcontroller of the backup system. A drive control device characterized by the following: