Motor control device

Abstract

In a motor control device that does not have a display device, the present invention provides a control device that can detect abnormalities in the motor or motor control device when an abnormality occurs. [Solution] The motor control device 10 has a control unit 30 that controls the operation of a motor 20 having an output shaft. It also has an abnormality detection unit 31 that detects that at least one of the motor 20 and the motor control device 10 is in an abnormal state different from the normal state, and an abnormal motor control unit 35 that controls the operation of the motor according to the detection result of the abnormality detection unit 31. When the abnormality detection unit 31 detects an abnormal state, the abnormal motor control unit 35 stops the drive rotation of the motor 20 and controls the operation of the output shaft differently from the operation in the normal state when an external force is applied in the rotational direction of the output shaft.

Description

Technical Field

[0001] The present invention relates to a motor control device.

Background Art

[0002] A motor control device that detects an abnormality and controls the driving of a motor is known. For example, Patent Document 1 discloses a motor control device having a microprocessor that compares a count value of an encoder counter with a value stored in advance in a storage device to determine whether it is normal or abnormal, and controls the driving of the motor.

[0003] The motor control device of Patent Document 1 includes a display device. The microprocessor determines the abnormality and displays an error on the display device.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, in a motor control device that controls a relatively simple motor such as a small brushless DC motor, there is a motor control device that does not include a display device as in Patent Document 1. In such a motor control device, when an abnormality occurs in the motor or the motor control device, it may not be possible to identify whether an abnormality has occurred, and the cause of the abnormality may not be known.

[0006] Therefore, there is a need for a motor control device that can distinguish between a normal state and an abnormal state even when the motor control device does not include a display device for displaying the abnormality when an abnormality occurs in at least one of the motor and the motor control device.

[0007] The object of the present invention is to provide a motor control device that can easily identify an abnormal state in at least one of the motor and the motor control device with a simple configuration, even without a display device for indicating abnormalities. [Means for solving the problem]

[0008] A motor control device according to one embodiment of the present invention includes a control unit that controls the operation of a motor having an output shaft. The control unit includes an abnormality detection unit that detects that at least one of the motor and the motor control device is in an abnormal state different from a normal state, and an abnormal motor control unit that controls the operation of the motor according to the detection result of the abnormality detection unit. When the abnormality detection unit detects the abnormal state, the abnormal motor control unit stops the drive rotation of the motor and controls the operation of the output shaft in a way that is different from the operation in the normal state when an external force is applied to the motor in the rotational direction of the output shaft. [Effects of the Invention]

[0009] According to one exemplary embodiment of the present invention, a motor control device can be provided that allows for easy detection of abnormal conditions in at least one of the motor and the motor control device with a simple configuration. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a control block diagram showing the schematic configuration of the motor control device. [Figure 2] Figure 2 is a schematic cross-sectional view of the motor along the line II-II in Figure 1. [Figure 3] Figure 3 is a schematic circuit diagram showing the general configuration of the motor drive control unit. [Figure 4] Figure 4 is a schematic circuit diagram showing the state of the motor drive control unit when it receives a normal motor drive signal. [Figure 5] Figure 5 is a schematic circuit diagram showing the state in which the output shaft can be rotated. [Figure 6]Figure 6 is a schematic circuit diagram showing the output shaft rotation stopped state. [Figure 7] Figure 7 is a schematic diagram illustrating how the output shaft switches between a rotatable state and a stopped state when the rotatable time or the rotation stop time has elapsed. [Figure 8] Figure 8 is a control block diagram showing the schematic configuration of the motor control device according to Modified Example 1. [Figure 9] Figure 9 is a schematic diagram showing how the motor drive control unit, upon receiving the first abnormal motor drive signal, switches between an output shaft rotatable state and an output shaft rotation stopped state at the timing when the first elapsed time has elapsed. [Figure 10] Figure 10 is a schematic diagram showing how the motor drive control unit, upon receiving the second abnormal motor drive signal, switches between an output shaft rotation enabled state and an output shaft rotation stopped state at the timing when the second elapsed time has elapsed. [Figure 11] Figure 11 is a schematic diagram showing how the motor drive control unit, upon receiving the first abnormal motor drive signal, switches the output shaft rotation enabled state to the output shaft rotation stopped state at the first rotation angle where the number of cogging torques generated when an external force is applied to the output shaft rotates equals the first number. [Figure 12] Figure 12 is a schematic diagram showing how the motor drive control unit, upon receiving the second abnormal motor drive signal, switches the output shaft rotation enabled state to the output shaft rotation stopped state at the second rotation angle, where the number of cogging torques generated when an external force is applied and the output shaft rotates becomes the second number. [Figure 13] Figure 13 is a control block diagram showing the schematic configuration of the motor control device in modified example 2. [Figure 14] Figure 14 shows how multiple motor control devices in another embodiment are integrated and controlled by an integrated control device. [Modes for carrying out the invention]

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are denoted by the same reference numerals and their description will not be repeated.

[0012] [Embodiment 1] (Overall Configuration) Referring to FIGS. 1 and 2, a motor control device 10 according to an exemplary embodiment 1 of the present invention will be described. FIG. 1 is a control block diagram showing a schematic configuration of the motor control device 10. FIG. 2 is a schematic cross-sectional view of the motor 20 taken along line II-II in FIG. 1.

[0013] As shown in FIG. 1, the motor control device 10 is a device that controls the driving rotation of the motor 20. The motor control device 10 monitors at least one state of the motor 20 and the motor control device 10, and controls the driving rotation of the motor 20 according to the result.

[0014] As shown in FIG. 2, the motor 20 can adopt a configuration similar to a known inner rotor type motor. Specifically, the motor 20 has a rotor 21 having an output shaft 25 that is the rotation center axis, and a cylindrical stator 22 located radially outward of the rotor 21. The stator 22 has a plurality of coils 23 arranged at predetermined angles in the circumferential direction around the output shaft 25. The stator 22 of the motor 20 shown in FIG. 2 has six coils 23 arranged at an angle of 60 degrees in the circumferential direction. Note that the motor may adopt a configuration similar to a known outer rotor type motor.

[0015] As shown in FIGS. 1 and 2, the motor control device 10 has a control unit 30 and a motor drive control unit 40.

[0016] When the control unit 30 of the motor control device 10 detects an abnormality, the motor drive control unit 40 controls the motor 20 to stop the drive rotation of the output shaft 25. As shown in Figure 1, when the drive rotation of the output shaft 25 is stopped, the motor control device 10 controls the motor 20 so that the rotational movement of the output shaft 25 when an external force F is applied in the rotational direction of the output shaft 25 indicates the occurrence and type of abnormality. Details regarding the control unit 30 and the motor drive control unit 40 of the motor control device 10 will be described below.

[0017] (Control Unit) The control unit 30 detects whether an abnormality has occurred in at least one of the motor 20 and the motor control device 10, and transmits motor drive signals S1 and S2 to the motor drive control unit 40 according to the detection result. Upon receiving the motor drive signals S1 and S2, the motor drive control unit 40 controls the power supplied to the multiple coils 23. In this way, the motor control device 10 controls the drive rotation of the output shaft 25 of the motor 20.

[0018] The control unit 30 can employ a configuration similar to that of a known microcomputer, for example. The control unit 30 includes an abnormality detection unit 31 and a motor control unit 32.

[0019] The abnormality detection unit 31 detects that at least one of the motor 20 and the motor control device 10 is in an abnormal state different from the normal state. The abnormality detection unit 31 detects at least one of the normal state or an abnormal state based on the results of detection units (not shown) that monitor the state of each component of the motor 20 and each component of the motor control device 10, respectively.

[0020] The detection unit can employ a configuration similar to that of known sensors that measure various physical quantities such as rotation angle, rotation speed, temperature, acceleration, current, voltage, and time. A normal state means, for example, a state in which the various physical quantities obtained by the detection unit are within a predetermined threshold. An abnormal state means, for example, a state in which the various physical quantities are outside the threshold. Note that the normal state and abnormal state may be states based on thresholds determined based on various conditions arbitrarily set by the user, taking into consideration the type, specifications, characteristics, and environment in which the motor and motor control device are used.

[0021] As shown in Figure 1, the abnormality detection unit 31 transmits a normal signal Y to the motor control unit 32 if it detects a normal state, or an abnormality signal N if it detects an abnormal state.

[0022] The motor control unit 32 generates a signal to control the operation of the output shaft 25 of the motor 20 according to the detection result of the abnormality detection unit 31, and transmits this signal to the motor drive control unit 40. The motor control unit 32 has a normal motor control unit 33 and an abnormal motor control unit 35.

[0023] When the motor control unit 32 receives a normal motor drive signal Y, the normal motor control unit 33 transmits a normal motor drive signal S1 to the motor drive control unit 40. When the motor control unit 32 receives an abnormal motor drive signal N, the abnormal motor control unit 35 transmits an abnormal motor drive signal S2 to the motor drive control unit 40.

[0024] (Motor drive control unit) The motor drive control unit 40 will be described with reference to Figures 1 and 3 to 5. Figure 3 is a schematic circuit diagram showing the general configuration of the motor drive control unit 40. Figure 4 is a schematic circuit diagram showing the state of the motor drive control unit 40 when it receives the normal motor drive signal S1. Figure 5 is a schematic circuit diagram showing the output shaft rotation enabled state C1. Figure 6 is a schematic circuit diagram showing the output shaft rotation stopped state C2.

[0025] As shown in Figure 3, the motor drive control unit 40 is an electrical circuit having a plurality of switching elements 41 and a power supply E. The motor drive control unit 40 controls the power supplied to the plurality of coils of the motor 20 by switching the conductive state P1 and non-conductive state P0 of the plurality of switching elements 41 in response to motor drive signals S1 and S2 from the control unit 30. The motor drive control unit 40 corresponds to the switching circuit in the present invention.

[0026] The multiple switching elements 41 include a first element 41a, a second element 41b, a third element 41c, and a fourth element 41d. Each switching element 41a, 41b, 41c, and 41d forms a bridge circuit with respect to the motor 20. The first element 41a and the third element 41c are located on the input side of the motor 20. The second element 41b and the fourth element 41d are located on the output side of the motor 20.

[0027] In Figures 4 to 6, when each switching element 41a, 41b, 41c, and 41d is in a conducting state P1, it is shown with a solid line, and when it is in a non-conducting state P0, it is shown with a dashed line. Furthermore, depending on the state P1 and P0 of each switching element 41a, 41b, 41c, and 41d, the electrical circuits that conduct are shown with solid lines, and the electrical circuits that do not conduct are shown with dashed lines.

[0028] As shown in Figures 1 and 4, when the motor drive control unit 40 receives a normal motor drive signal S1 from the normal motor control unit 33, it sets the first element 41a and the fourth element 41d to a conductive state P1, and switches the second element 41b and the third element 41c to a non-conductive state P0. As a result, when the abnormality detection unit 31 detects a normal state, power is supplied to the motor 20 from the power supply E of the motor drive control unit 40, causing the output shaft 25 of the motor 20 to rotate.

[0029] On the other hand, the motor drive control unit 40, upon receiving the abnormal motor drive signal S2 from the abnormal motor control unit 35, performs the following stepwise control on the motor 20.

[0030] First, as shown in Figures 1 and 5, the motor drive control unit 40, upon receiving the abnormal motor drive signal S2, switches each of the switching elements 41a, 41b, 41c, and 41d to a non-conductive state P0. As a result, when the abnormality detection unit 31 detects an abnormal condition, power is not supplied to the motor 20 from the power supply E, and the drive rotation of the output shaft 25 can be stopped. Therefore, it is possible to prevent the output shaft 25 of the motor 20 from continuing to drive and rotate in an abnormal state.

[0031] Thus, when each switching element 41a, 41b, 41c, and 41d is in a non-conductive state P0, the output shaft 25, whose drive rotation is stopped, can be rotated by applying an external force F in the direction of rotation of the output shaft 25. Therefore, this state of the motor 20 and motor control device 10 is defined as the output shaft rotatable state C1.

[0032] Although not specifically shown in the diagram, when stopping the drive rotation of the output shaft 25 of the motor 20 in a normal state, the normal motor control unit 33, upon receiving the stop command, sends a stop signal to the motor drive control unit 40. Upon receiving the stop signal, the motor drive control unit 40 switches each of the switching elements 41a, 41b, 41c, and 41d to a non-conductive state P0, thereby putting the motor 20 and the motor control device 10 into an output shaft rotatable state C1. Therefore, in the output shaft rotatable state C1, where the drive rotation of the output shaft is stopped, it is impossible to distinguish between a normal state and an abnormal state.

[0033] Next, as shown in Figures 1 and 6, the motor drive control unit 40, upon receiving the abnormal motor drive signal S2, switches the third element 41c and the fourth element 41d to a conductive state P1 at a predetermined elapsed time, which will be described later, after the output shaft has been set to a rotatable state C1. In this way, by setting the third element 41c and the fourth element 41d to a conductive state P1 and the first element 41a and the second element 41b to a non-conductive state P0, the input and output sides of the motor 20 can be short-circuited. As a result, when the rotor 21 of the motor 20 rotates, a so-called short-circuit brake occurs due to the generation of a back electromotive force relative to the motor 20.

[0034] When an external force F is applied to the motor 20 in the direction of rotation of the output shaft 25 while the motor 20 is in a state where such short braking occurs, the rotation of the output shaft 25 is hindered by the short braking. Therefore, this state of the motor 20 and motor control device 10 is defined as the output shaft rotation stopped state C2.

[0035] Subsequently, the motor drive control unit 40, upon receiving the abnormal motor drive signal S2, switches the third element 41c and the fourth element 41d to a non-conductive state P0 at a predetermined time elapsed, for example, after setting the output shaft rotation to a stopped state C2 (described later). This switches the output shaft rotation to a rotatable state C1.

[0036] As described above, when the abnormality detection unit 31 detects an abnormal condition, the motor drive control unit 40, which receives the abnormal motor drive signal S2, is configured to switch between an output shaft rotatable state C1 and an output shaft rotation stopped state C2 at a timing, for example, after a predetermined elapsed time.

[0037] (Rotational motion of the output shaft when an external force is applied) (Control based on elapsed time) Referring to Figures 2 and 5 to 7, the operation of the output shaft 25 when an external force F is applied in the rotational direction of the output shaft 25 while the abnormality detection unit 31 has detected an abnormal condition and the drive rotation of the output shaft 25 of the motor 20 has stopped will be described.

[0038] Figure 7 is a schematic diagram showing how the motor drive control unit 40, upon receiving the abnormal motor drive signal S2 from the abnormal motor control unit 35, switches between the conductive state P1 and the non-conductive state P0 of the third element 41c and the fourth element 41d at the timing when the rotatable time T1a or rotation stop time T1b has elapsed, thereby switching between the output shaft rotatable state C1 and the output shaft rotation stop state C2. In Figure 7, the symbol T on the horizontal axis represents time.

[0039] As shown in Figure 7, when the motor drive control unit 40 receives the abnormal motor drive signal S2 from the abnormal motor control unit 35, it switches to the output shaft rotation stopped state C2 by making the third element 41c and the fourth element 41d conductive P1 after the rotation stop time T1a has elapsed since switching to the output shaft rotation stopped state C1. Furthermore, when the motor drive control unit 40 switches to the output shaft rotation enabled state C1 by making the third element 41c and the fourth element 41d non-conductive P0 after the rotation stop time T1b has elapsed since switching to the output shaft rotation stopped state C2.

[0040] As a result, when the abnormality detection unit 31 detects an abnormal condition, the output shaft 25 rotates during the rotatable time T1a and does not rotate during the rotation stop time T1b, repeating this rotational operation periodically while an external force F is applied. In this embodiment, the rotatable time T1a and the rotation stop time T1b are set to the same elapsed time.

[0041] (Control by rotation angle) Furthermore, as shown in Figures 2, 5, and 6, the motor drive control unit 40, upon receiving the abnormal motor drive signal S2 from the abnormal motor control unit 35, may temporarily switch the output shaft rotatable state C1 to the output shaft rotation stopped state C2, depending on the rotation angle R of the output shaft 25 that is rotated by the applied external force F.

[0042] Specifically, when the motor drive control unit 40 receives an abnormal motor drive signal S2 from the abnormal motor control unit 35, and the output shaft 25, which is rotating when an external force F is applied in the output shaft rotatable state C1, rotates to an angle corresponding to the rotation angle R, the motor drive control unit 40 may temporarily activate the third element 41c and the fourth element 41d to a conductive state P1 and switch to the output shaft rotation stopped state C2.

[0043] In this case, the motor drive control unit 40 switches to the output shaft rotation-stopped state C2, and after a predetermined time has elapsed, it switches the third element 41c and the fourth element 41d to the non-conductive state P0, thereby switching to the output shaft rotation-enabled state C1. Thereafter, the same operation is repeated for each rotation angle R.

[0044] As a result, when the abnormality detection unit 31 detects an abnormal condition, the output shaft 25 performs a rotational motion in which, while an external force F is applied, it rotates by an angle corresponding to the rotation angle R, and then temporarily stops rotating, repeating this motion periodically.

[0045] As described above, when the abnormality detection unit 31 detects a normal state, the output shaft 25 simply rotates according to the external force F applied in the rotational direction in the output shaft rotatable state C1. On the other hand, when the abnormality detection unit 31 detects an abnormal state, the abnormal motor control unit 35 stops the drive rotation of the motor 20 and then, via the motor drive control unit 40, executes control for the motor 20 to perform a rotational operation that periodically repeats the operation in which the output shaft 25 rotates according to the external force F applied in the rotational direction of the output shaft 25 and the operation in which the output shaft 25 does not rotate.

[0046] As a result, even if the drive rotation of the output shaft 25 of the motor 20 stops due to some abnormality, and it is not possible to determine by visual inspection whether the stop is due to a normal condition or an abnormal condition, it is possible to confirm whether or not an abnormality has occurred in at least one of the motor 20 and the motor control device 10 by checking the rotational movement of the output shaft 25 to which an external force F has been applied.

[0047] The motor control device 10 according to the embodiment described above includes a control unit 30 that controls the operation of a motor 20 having an output shaft 25. The control unit 30 includes an abnormality detection unit 31 that detects that at least one of the motor 20 and the motor control device 10 is in an abnormal state different from the normal state, and an abnormal motor control unit 35 that controls the operation of the motor 20 according to the detection result of the abnormality detection unit 31. When the abnormality detection unit 31 detects an abnormal state, the abnormal motor control unit 35 stops the drive rotation of the motor 20 and controls the operation of the output shaft 25 differently from the operation in the normal state when an external force F is applied to the motor 20 in the rotational direction of the output shaft 25.

[0048] According to the above configuration, when the abnormality detection unit 31 detects an abnormal condition, the abnormality motor control unit 35 controls the motor 20 so that when an external force F is applied to the output shaft 25 in the rotational direction while the drive rotation is stopped, the operation of the output shaft 25 is different from that of a normal state.

[0049] This allows the operation of the output shaft 25 to be used to communicate normal and abnormal states to the user. Therefore, even in a motor control device 10 that does not have a display device for showing abnormal states, normal and abnormal states can be identified by the difference in the rotational operation of the output shaft 25. Thus, a motor control device 10 can be provided that allows for easy identification of abnormal states in at least one of the motor 20 and the motor control device 10 with a simple configuration.

[0050] Furthermore, normal and abnormal conditions can be identified through simple operations.

[0051] Furthermore, if the abnormality detection unit 31 detects an abnormal condition, the abnormality motor control unit 35 stops the motor 20 from rotating, thereby suppressing the progression of an abnormality occurring in at least one of the motor 20 and the motor control device 10.

[0052] In this embodiment, when the abnormality detection unit 31 detects an abnormal condition, the abnormality motor control unit 35 controls the motor 20 to switch between an output shaft rotatable state C1, in which the output shaft 25 can rotate due to an external force F applied in the rotational direction, and an output shaft rotation-stopped state C2, in which the output shaft 25 does not rotate even when an external force F is applied, according to the rotation angle R of the output shaft 25, or the rotation-stopped time T1a or rotation-stopped time T1b, which are the elapsed time in either the output shaft rotatable state C1 or the output shaft rotation-stopped state C2.

[0053] According to the above configuration, when an abnormal condition is detected in at least one of the motor 20 and the motor control device 10, the motor 20 can be controlled to switch between an output shaft rotatable state C1 and an output shaft rotation-stopped state C2, depending on the rotation angle of the output shaft 25, or the rotation-stopped time T1a in the output shaft rotatable state C1 or the rotation-stopped time T1b in the output shaft rotation-stopped state C2.

[0054] This makes it possible to more reliably determine whether an abnormal condition is occurring by applying an external force F to the output shaft 25. Therefore, a motor control device 10 can be provided that can more reliably confirm an abnormal condition without using a display device that indicates an abnormal condition.

[0055] Furthermore, the conditions for switching between the output shaft rotatable state C1 and the output shaft rotation-stopped state C2, namely the rotatable time T1a and the rotation-stopped time T1b, or the rotation angle R of the output shaft 25 when an external force F is applied, may be arbitrarily determined by the user of the motor control device 10. This allows the user to arbitrarily set the rotational operation of the output shaft 25 when an external force F is applied. Therefore, abnormal conditions can be identified by the rotational operation of the output shaft 25, which is easily recognizable to the user, depending on the type and size of the motor 1, the operating environment, etc.

[0056] The motor control device 10 according to this embodiment further includes a motor drive control unit 40 which has a plurality of switching elements 41 constituting a bridge circuit and is electrically connected to the input and output sides of the motor 20. When the abnormality detection unit 31 detects an abnormal condition, the abnormality motor control unit 35 drives the third element 41c and the fourth element 41d, which are part of the switching elements 41, to temporarily short-circuit the input and output sides of the motor 20.

[0057] According to the above configuration, when an abnormal condition is detected in at least one of the motor 20 and the motor control device 10, the third element 41c and the fourth element 41d, which are part of the switching element 41 of the motor drive control unit 40, can be driven to temporarily short-circuit the input side and the output side of the motor 20.

[0058] This makes it possible to more reliably prevent the rotation of the output shaft 25 to which an external force F is applied in the rotational direction. Therefore, an abnormal condition in at least one of the motor 20 and the motor control device 10 can be reliably confirmed by rotating the output shaft 25.

[0059] [Modification 1 of Embodiment 1] (Motor control device that detects multiple types of abnormalities) Next, a motor control device 100 according to Modification 1 of Embodiment 1 will be described with reference to Figures 8 to 12. Figure 8 is a control block diagram showing the schematic configuration of the motor control device 100 according to Modification 1 of Embodiment 1.

[0060] Figure 9 is a schematic diagram showing how the motor drive control unit 140, upon receiving the first abnormal motor drive signal S21, switches between the output shaft rotatable state C1 and the output shaft rotation stopped state C2 at the timing of the first elapsed time T11a, T11b. Figure 10 is a schematic diagram showing how the motor drive control unit 140, upon receiving the second abnormal motor drive signal S22, switches between the output shaft rotatable state C1 and the output shaft rotation stopped state C2 at the timing of the second elapsed time T21a, T21b.

[0061] Figure 11 is a schematic diagram showing a cross-sectional view between XI and XI in Figure 8, illustrating how the motor drive control unit 140, upon receiving the first abnormal motor drive signal S21, switches from the output shaft rotatable state C1 to the output shaft rotation-stopped state C2 at a first rotation angle R1 where the number of cogging torques generated when the output shaft 25 rotates due to the application of an external force F becomes the first number. Figure 12 is a schematic diagram showing a cross-sectional view between XII and XII in Figure 8, illustrating how the motor drive control unit 140, upon receiving the second abnormal motor drive signal S22, switches from the output shaft rotatable state C1 to the output shaft rotation-stopped state C2 at a second rotation angle R2 where the number of cogging torques generated when the output shaft 25 rotates due to the application of an external force F becomes the second number. The details of the relationship between the number of cogging torques and the rotation angle will be described later.

[0062] In the following description, the same reference numerals are used for components used in the description of Embodiment 1, and their descriptions are omitted. Only components that differ from those in Embodiment 1 will be described.

[0063] As shown in Figure 8, the motor control device 100 according to modified example 1 has a control unit 130 and a motor drive control unit 140. The control unit 130 has an abnormality detection unit 131 and a motor control unit 132.

[0064] The abnormality detection unit 131 detects abnormal states corresponding to the type of abnormality when multiple types of abnormalities occur in at least one of the motor 20 and the motor control device 100. Note that multiple types of abnormal states may be, for example, states determined by conditions based on different types of physical quantities, such as rotation angle, rotation speed, temperature, acceleration, current, voltage, and time, obtained by a detection unit (not shown). Alternatively, the same type of physical quantity may be used, but the state may be determined by conditions such as different specifications, characteristics, modes, placement, measurement environment, and threshold settings of the detection unit.

[0065] When the abnormality detection unit 131 detects multiple types of abnormal conditions, it transmits multiple types of abnormality signals N1, N2, ... corresponding to the type of abnormality to the motor control unit 132.

[0066] In this modified example 1, for the sake of clarity, we will describe a case where the abnormality detection unit 131 detects two types of abnormal states, a first abnormal state and a second abnormal state, and transmits two types of abnormal signals, a first abnormal signal N1 and a second abnormal signal N2, to the motor control unit 132. However, the abnormality detection unit may detect three or more types of abnormalities and transmit three or more types of abnormal signals to the motor control unit.

[0067] The motor control unit 132 includes a normal motor control unit 33 and an abnormal motor control unit 135. When the motor control unit 132 receives a first abnormal signal N1, the abnormal motor control unit 135 transmits a first abnormal motor drive signal S21 to the motor drive control unit 140. Similarly, when the motor control unit 132 receives a second abnormal signal N2, the abnormal motor control unit 135 transmits a second abnormal motor drive signal S22 to the motor drive control unit 140.

[0068] In other words, when the motor control unit 132 receives multiple types of abnormal signals N1 and N2, the abnormal motor control unit 135 transmits multiple types of abnormal motor drive signals S21 and S22 to the motor drive control unit 140, corresponding to the type of abnormality.

[0069] (Control where the elapsed time differs depending on the type of anomaly) As shown in Figures 9 and 10, the motor drive control unit 140, upon receiving multiple types of abnormal motor drive signals S21 and S22 from the abnormal motor control unit 135, controls the motor 20 such that the rotatable time T11a and T21a in the output shaft rotatable state C1 and the rotation stop time T11b and T21b in the output shaft rotation stop state C2 differ according to the multiple types of abnormal motor drive signals S21 and S22.

[0070] Specifically, as shown in Figure 9, when the motor drive control unit 140 receives the first abnormal motor drive signal S21 from the abnormal motor control unit 135, it switches the third element 141c and the fourth element 141d, which are in a non-conductive state P0, to a conductive state P1 at the timing when the first rotational possible time T11a has elapsed, with reference to the time when the first abnormal motor drive signal S21 was received, and switches the output shaft rotational possible state C1 to an output shaft rotation stopped state C2. Subsequently, when the first rotation stopped time T11b has elapsed, the motor drive control unit 140 switches the third element 141c and the fourth element 141d, which are in a conductive state P1, back to a non-conductive state P0, and switches the output shaft rotation stopped state C2 to an output shaft rotational possible state C1. Subsequently, the motor drive control unit 140 switches the output shaft rotatable state C1 to the output shaft rotation stopped state C2 when the first rotational time T11a has elapsed, and then switches the output shaft rotation stopped state C2 to the output shaft rotatable state C1 when the first rotational stop time T11b has elapsed, repeating this operation. Note that the first rotational time T11a is set to the same elapsed time as the first rotational stop time T11b.

[0071] In response to this, as shown in Figure 10, the motor drive control unit 140, upon receiving the second abnormal motor drive signal S22 from the abnormal motor control unit 135, switches the output shaft rotatable state C1 to the output shaft rotation stopped state C2 at the timing when the second rotation-possible time T21a has elapsed, with reference to the time when the second abnormal motor drive signal S22 was received. Subsequently, the motor drive control unit 140 switches the output shaft rotation stopped state C2 to the output shaft rotatable state C1 at the timing when the second rotation-possible time T21b has elapsed. After that, the motor drive control unit 140 repeats the operation of switching the output shaft rotatable state C1 to the output shaft rotation stopped state C2 at the timing when the second rotation-possible time T21a has elapsed, and switching the output shaft rotation stopped state C2 to the output shaft rotatable state C1 at the timing when the second rotation-possible time T21b has elapsed. Note that the second rotation-possible time T21a is set to the same elapsed time as the second rotation-possible time T21b.

[0072] Here, as shown in Figures 9 and 10, the first rotation time T11a is different from the second rotation time T21a. Similarly, the first rotation stop time T11b is different from the second rotation stop time T21b.

[0073] As a result, when the abnormality detection unit 131 detects a first abnormal condition, the output shaft 25 performs a first rotational operation in which it rotates during a first rotational time T11a and does not rotate during a first rotational stop time T11b, while an external force F is applied.

[0074] On the other hand, if the abnormality detection unit 131 detects a second abnormal condition, the output shaft 25 performs a second rotational operation in which, while an external force F is applied, it rotates during a second rotational time T21a which is different from the first rotational time T11a, and does not rotate during a second rotational stop time T21b which is different from the first rotational stop time T11b, repeating this operation periodically.

[0075] (Control that generates different numbers of cogging torques depending on the type of abnormality) The number of cogging torque events generated when an external force F is applied to rotate the output shaft 25 is determined by the number of coils in the motor. In other words, in a single motor with a constant number of coils, the rotation angle at which cogging torque occurs once is constant. For example, as shown in Figures 11 and 12, if the motor 20 has six coils 23, the number of cogging torque events generated when an external force F is applied to rotate the output shaft 25 is six. In other words, in the motor 20, the rotation angle at which cogging torque occurs once is 60 degrees. In this way, the difference in the rotation angle of the motor's output shaft can be determined by counting the number of times cogging torque occurs.

[0076] As shown in Figures 8, 11, and 12, the motor drive control unit 140, upon receiving multiple types of abnormal motor drive signals S21 and S22 from the abnormal motor control unit 135, may temporarily switch the output shaft rotatable state C1 to the output shaft rotation stopped state C2 at rotation angles R1 and R2 such that the number of cogging torques generated when the output shaft 25, to which an external force F is applied, rotates differs according to the type of abnormality.

[0077] For example, as shown in Figures 8 and 11, the motor drive control unit 140, upon receiving the first abnormal motor drive signal S21, may temporarily switch the output shaft rotatable state C1 to the output shaft rotation stopped state C2 at a first rotation angle R1 where the number of cogging torques generated when the output shaft 25 to which an external force F is applied is 3.

[0078] In this case, as shown in Figures 8 and 12, the motor drive control unit 140, upon receiving the second abnormal motor drive signal S22, may temporarily switch the output shaft rotatable state C1 to the output shaft rotation stopped state C2 at a second rotation angle R2 where the number of cogging torques generated when the output shaft 25 to which the external force F is applied is 2.

[0079] As a result, when the abnormality detection unit 131 detects a first abnormal state, the output shaft 25 performs a first rotational operation in which, while an external force F is applied, it rotates due to the external force F and temporarily stops when the cogging torque count reaches three, repeating this operation periodically. On the other hand, when the abnormality detection unit 131 detects a second abnormal state, the output shaft 25 performs a second rotational operation in which, while an external force F is applied, it rotates due to the external force F and temporarily stops when the cogging torque count reaches two, repeating this operation periodically.

[0080] As described above, when the abnormality detection unit 131 detects two types of abnormalities, the abnormality motor control unit 35 stops the drive rotation of the motor 20 and then, via the motor drive control unit 140, applies an external force F to the motor 20 in the direction of rotation of the output shaft 25. In this case, the first rotational movement of the output shaft 25 when the first abnormality is detected is controlled differently from the second rotational movement of the output shaft 25 when the second abnormality is detected.

[0081] Similarly, if the abnormality detection unit detects three or more types of abnormalities, the abnormality motor control unit may perform different control actions on the rotational movement of the output shaft, which is subjected to an external force in the rotational direction, depending on the type of abnormality.

[0082] In this case, the abnormal motor control unit may perform control on the motor to switch between a state where the output shaft can rotate and a state where the output shaft rotation is stopped, at different elapsed times depending on the type of abnormality.

[0083] Furthermore, the abnormal motor control unit may perform control on the motor to temporarily switch the output shaft rotation enabled state to an output shaft rotation stopped state at different rotation angles depending on the type of abnormality.

[0084] The abnormality detection unit 131 in the motor control device 100 according to the modified example 1 described above can detect multiple types of abnormal conditions. When the abnormality detection unit 131 detects multiple types of abnormal conditions, the abnormal motor control unit 135 controls the operation of the output shaft 25 of the motor 20 differently depending on the type of abnormal condition, when an external force F is applied to the output shaft 25 in the rotational direction of the output shaft 25.

[0085] According to the above configuration, when multiple types of abnormal conditions are detected in at least one of the motor 20 and the motor control device 100, the rotational movement of the output shaft 25 can be made different depending on the type of abnormal condition when the motor 20 is controlled to apply an external force F to the output shaft 25.

[0086] As a result, even in motor control devices that do not have a display device that shows the type of abnormal condition, the type of abnormal condition can be identified by the difference in the rotational movement of the output shaft 25 when an external force F is applied. Therefore, a motor control device 100 that can identify the type of abnormal condition can be provided with a simpler configuration that does not require the aforementioned display device.

[0087] In this modified example 1, when the abnormality detection unit 131 detects multiple types of abnormal conditions, the abnormality motor control unit 135 controls the motor 20 to switch between an output shaft rotatable state C1, where the output shaft 25 can rotate due to an external force F applied in the rotational direction, and an output shaft rotation-stopped state C2, where the output shaft 25 does not rotate even when an external force F is applied, at different timings depending on the type of abnormal condition, based on the rotation angles R1, R2 of the output shaft 25, or the elapsed time T11a, T11b, T21a, T21b in either the output shaft rotatable state C1 or the output shaft rotation-stopped state C2.

[0088] To explain with a specific example, if the abnormality detection unit 131 detects two types of abnormal conditions, in the first abnormal condition, the abnormal motor control unit 135 controls the motor 20 to temporarily switch from the output shaft rotatable state C1 to the output shaft rotation-stopped state C2 at the timing when the output shaft 25 to which an external force F is applied rotates to an angle of the first rotation angle R1.

[0089] In contrast, in the second abnormal state, the abnormal motor control unit 135 controls the motor 20 to temporarily switch from the output shaft rotatable state C1 to the output shaft rotation-stopped state C2 at the moment when the output shaft 25 to which an external force F is applied rotates to a second rotation angle R2, which is a different rotation angle from the first rotation angle R1.

[0090] Similarly, if the abnormality detection unit 131 detects two types of abnormal conditions, in the first abnormal condition, the abnormal motor control unit 135 controls the motor 20 to switch between an output shaft rotatable state C1 and an output shaft rotation stopped state C2 at the timing when the first elapsed times T11a and T11b have elapsed.

[0091] In contrast, in the second abnormal state, the abnormal motor control unit 135 controls the motor 20 to switch between an output shaft rotatable state C1 and an output shaft rotation stopped state C2 at the timing when a second elapsed time T21a, T21b, which is a different elapsed time from the first elapsed times T11a, T11b, has elapsed.

[0092] According to the above configuration, by utilizing the functions of the motor control device 100 and the characteristics of the motor 20, when multiple types of abnormal conditions are detected in at least one of the motor 20 and the motor control device 100, the output shaft rotation enabled state C1 and the output shaft rotation stopped state C2 of the motor 20 can be switched at different timings depending on the type of abnormal condition.

[0093] As a result, the rotational movement of the output shaft 25 when an external force F is applied to it differs depending on the type of abnormal condition. Therefore, the type of abnormal condition can be identified by the difference in the rotational movement of the output shaft 25. Thus, even when multiple types of abnormal conditions are detected, the type of abnormal condition can be identified more reliably with a simpler configuration.

[0094] In this modified example 1, when the abnormality detection unit 131 detects multiple types of abnormal conditions, the abnormality motor control unit 135 controls the motor 20 to switch from the output shaft rotatable state C1 to the output shaft rotation stopped state C2 at rotation angles R1 and R2 such that the number of cogging torques generated when the output shaft 25 rotates due to an external force F applied in the rotational direction in the output shaft rotatable state C1 differs according to the type of abnormal condition.

[0095] According to the above configuration, when multiple types of abnormal conditions are detected in at least one of the motor 20 and the motor control device 100, the motor 20 can perform control to switch from an output shaft rotatable state C1 to an output shaft rotation-stopped state C2, with the number of cogging torques generated when an external force F is applied to the output shaft 25 being determined by different rotation angles depending on the type of abnormal condition.

[0096] This allows for the identification of different types of abnormal conditions by counting the number of cogging torque events. Therefore, the type of abnormal condition can be identified more easily.

[0097] [Modification 2 of Embodiment 1] A motor control device 200 having a rotation stop unit 250 will be described with reference to Figure 13. Figure 13 is a control block diagram showing the schematic configuration of the motor control device 200 in modified example 2. In the following, the same reference numerals are used for the components used in the description of Embodiment 1, and their descriptions are omitted. Only components that differ from the configuration of Embodiment 1 will be described.

[0098] As shown in Figure 13, the motor control device 200 includes a control unit 230, a motor drive control unit 40, and a rotation stop unit 250.

[0099] The control unit 230 includes an abnormality detection unit 31 and a motor control unit 232. The motor control unit 232 includes a normal motor control unit 33 and an abnormal motor control unit 235.

[0100] When the motor control unit 232 receives an abnormality signal N, the abnormality motor control unit 235 transmits an abnormality motor drive signal S2 to the motor drive control unit 40 and a rotation stop signal S30 to the rotation stop unit 250.

[0101] Upon receiving a rotation stop signal S30 from the abnormal motor control unit 235, the rotation stop unit 250 is controlled by the abnormal motor control unit 235 to mechanically stop the rotation of the output shaft 25 to which an external force F is applied, in the output shaft rotation stop state C2. This allows the rotation stop unit 250 to perform a mechanical stopping operation on the motor 20 in parallel with the short brake performed by the motor drive control unit 40.

[0102] The rotation stop unit 250 is controlled by the abnormal motor control unit 235 to release the mechanical stop of the output shaft 25 when the output shaft is in a rotatable state C1, thereby enabling the output shaft 25 to rotate due to an external force F.

[0103] The rotation stopping unit 250 can employ the same configuration as a known brake mechanism for stopping the rotation of the output shaft 25. The rotation stopping unit 250 is, for example, a mechanism that presses brake pads, discs, etc., against the rotating body of the motor.

[0104] The motor control device 200 according to the embodiment described above further includes a rotation stop unit 250 that, when the abnormality detection unit 231 detects an abnormal condition, is controlled by the abnormality motor control unit 235 to mechanically stop the output shaft 25 without rotating it, even if an external force F is applied to the output shaft 25 in the rotational direction.

[0105] According to the above configuration, if an abnormal condition is detected in at least one of the motor 20 and the motor control device 200, the rotation stop unit 250 can mechanically stop the rotation of the output shaft 25. This makes it possible to more reliably prevent the rotation of the output shaft 25 in the event of an abnormal condition. Therefore, the abnormal condition can be recognized more reliably.

[0106] Furthermore, even if an abnormality occurs in which the motor drive control unit 40 is unable to activate the short brake, the rotational movement of the output shaft 25 to which the external force F is applied can be mechanically stopped by the rotation stop unit 250. Therefore, even if an abnormality occurs in which the short brake cannot be activated, the abnormal condition can be identified. Note that multiple types of abnormal conditions may be identified by using both the short brake and the rotation stop unit 250 to stop the engine.

[0107] (Other embodiments) Although embodiments of the present invention have been described above, the embodiments described above are merely examples for carrying out the present invention. Therefore, the invention is not limited to the embodiments described above, and it is possible to carry out the invention by appropriately modifying the embodiments described above without departing from the spirit of the invention.

[0108] Figure 14 shows how multiple motor control devices 300 are integrated and controlled by an integrated control device 390. As shown in Figure 14, multiple motor control devices 300, each controlling multiple motors 320, may be integrated and controlled by a single integrated control device 390. This allows multiple motors 320 and multiple motor control devices 300 to be managed collectively by the integrated control device 390.

[0109] In Embodiment 1 and its various modifications, the motor drive control units 40 and 140 have a bridge circuit with four switching elements. However, the motor drive control unit may have additional switching elements inside or outside the bridge circuit, for example, to control the motor. Also, the motor drive control unit does not need to have a bridge circuit, as long as it can control the motor's rotation.

[0110] In the above embodiment 1 and its various modifications, the motor drive control units 40 and 140, upon receiving the normal motor drive signal S1 from the normal motor control unit 33, set the first element 41a and the fourth elements 41d and 141d to a conductive state P1, and switch the second element 41b and the third elements 41c and 141c to a non-conductive state P0. However, the motor drive control unit, upon receiving the normal motor drive signal from the normal motor control unit, may set the second and third elements to a conductive state, and switch the first and fourth elements to a non-conductive state.

[0111] In the above embodiment 1 and its various modifications, in the output shaft rotatable state C1, the input and output sides of the motor 20 are short-circuited by making the third element 41c, 141c and the fourth element 41d, 141d conductive P1 and making the first element 41a and the second element 41b non-conductive P0. However, in the output shaft rotatable state, the input and output sides of the motor may also be short-circuited by making the first and second elements conductive and the third and fourth elements non-conductive.

[0112] In Embodiment 1, the rotational time T1a and the rotational stop time T1b are set to the same elapsed time. In Modification 1, when the first abnormality occurs, the rotational time T11a and the rotational stop time T11b are set to the same elapsed time. When the second abnormality occurs, the rotational time T21a and the rotational stop time T21b are set to the same elapsed time. However, when representing the same abnormal condition, the rotational time and the rotational stop time may be set to different elapsed times.

[0113] In Embodiment 1 and its various modifications, the motor drive control units 40 and 140, upon receiving the abnormal motor drive signals S2, S21, and S22, switch each of the switching elements 41a, 41b, 41c, 141c, 41d, and 141d to a non-conductive state P0, thereby stopping the drive rotation of the output shaft 25. However, the drive rotation of the output shaft may also be stopped using a short brake. This allows for a more reliable stopping of the output shaft and enables the abnormal condition to be communicated to the user more quickly.

[0114] In the above embodiment 1 and its various modifications, the abnormal motor control units 35, 135, and 235 perform control to switch between the output shaft rotatable state C1 and the output shaft rotation-stopped state C2 when the abnormality detection units 31 and 131 detect an abnormal condition, either when the output shaft to which an external force F is applied rotates to a rotation angle R, R1, or R2, or when the rotation-possible time T1a, T11a, T21a or rotation-stopped time T1b, T11b, T21b has elapsed. However, the abnormal motor control unit may also perform control to switch between the output shaft rotatable state and the output shaft rotation-stopped state at a timing based on a combination of multiple conditions among the rotation angle of the output shaft, the rotation-possible time, and the rotation-stopped time. Alternatively, the abnormal motor control unit may also perform control to switch between the output shaft rotatable state and the output shaft rotation-stopped state at a predetermined timing based on conditions other than the rotation angle of the output shaft, the rotation-possible time, or the rotation-stopped time.

[0115] In the above modified example 2, a mechanical stopping operation by the rotation stop unit 250 is performed on the motor 20 in parallel with the short braking performed by the motor drive control unit 40. However, the motor drive control unit may not perform short braking on the motor, and only the mechanical stopping operation by the rotation stop unit may be performed.

[0116] [Example Configuration] Furthermore, this technology can also be configured as follows:

[0117] (1) The motor control device has a control unit that controls the operation of a motor having an output shaft. The control unit has an abnormality detection unit that detects that at least one of the motor and the motor control device is in an abnormal state different from the normal state, and an abnormal motor control unit that controls the operation of the motor according to the detection result of the abnormality detection unit. When the abnormality detection unit detects the abnormal state, the abnormal motor control unit stops the drive rotation of the motor and controls the operation of the output shaft in a way that is different from the operation in the normal state when an external force is applied to the motor in the rotational direction of the output shaft.

[0118] (2) In the motor control device described in (1), the abnormal motor control unit, when the abnormality detection unit detects the abnormal state, controls the motor to switch between an output shaft rotatable state in which the output shaft can rotate due to an external force applied in the rotational direction, and an output shaft rotation stopped state in which the output shaft does not rotate even when the external force is applied, according to the rotation angle of the output shaft, or the elapsed time in either the output shaft rotatable state or the output shaft rotation stopped state.

[0119] (3) In the motor control device described in (1), the abnormality detection unit detects multiple types of abnormal conditions. When the abnormality detection unit detects one of the multiple types of abnormal conditions, the abnormal motor control unit controls the operation of the output shaft when an external force is applied to the motor in the rotational direction of the output shaft, with the operation of the output shaft varying depending on the type of abnormal condition.

[0120] In the motor control device described in (4)(3), the abnormal motor control unit, when the abnormality detection unit detects one of the multiple types of abnormal conditions, controls the motor to switch between an output shaft rotatable state in which the output shaft can rotate due to an external force applied in the rotational direction, and an output shaft rotation stopped state in which the output shaft does not rotate even when the external force is applied, at different timings depending on the type of abnormal condition, based on the rotation angle of the output shaft or the elapsed time in either the output shaft rotatable state or the output shaft rotation stopped state.

[0121] (5)(4) In the motor control device described above, when the abnormality detection unit detects one of the multiple types of abnormal conditions, the abnormality motor control unit controls the motor to switch from the output shaft rotatable state to the output shaft rotation stopped state at a rotation angle in which the number of times cogging torque is generated when the output shaft rotates due to an external force applied in the rotational direction while the output shaft is rotatable differs according to the type of abnormal condition.

[0122] (6) The motor control device described in any one of (1) to (5) further has a switching circuit having a plurality of switching elements that constitute a bridge circuit and is electrically connected to the input and output sides of the motor. The abnormal motor control unit performs control to temporarily short-circuit the input and output sides of the motor by driving a portion of the switching elements when the abnormal detection unit detects the abnormal state.

[0123] (7) The motor control device described in any one of (1) to (6) further includes a rotation stop unit that, when the abnormality detection unit detects the abnormal condition, is controlled by the abnormal motor control unit to mechanically stop the output shaft without rotating it, even if an external force is applied to the output shaft in the rotational direction. [Industrial applicability]

[0124] The present invention is applicable to a motor control device having a control unit that controls the operation of a motor having an output shaft. [Explanation of Symbols]

[0125] 10,100,200,300 Motor control device 20,320 motors 21 Rotors 22 stata 23 coils 25 Output shaft 30,130,230 Control Unit 31,131 Anomaly detection unit 32,132,232 Motor control unit 33 Motor control unit under normal conditions 35,135,235 Motor control unit in case of abnormality 40,140 Motor drive control unit 41 Switching elements 41a, 41b, 41c, 41d, 141c, 141d element 250 Rotation stop section 390 Integrated Control Unit C1 Output shaft rotatable state C2 Output shaft rotation stopped state E power supply F external force Y Normal signal N,N1,N2 Abnormal signal S1 Normal motor drive signal S2, S21, S22 Motor drive signal in case of abnormality S30 Rotation stop signal P0 Non-conductive state P1 Continuity state T1a, T11a, T21a Rotation time T1b, T11b, T21b Rotation stop time R, R1, R2 Rotation angles

Claims

1. In a motor control device having a control unit that controls the operation of a motor having an output shaft, The control unit, An abnormality detection unit that detects that at least one of the motor and the motor control device is in an abnormal state different from the normal state, An abnormal motor control unit controls the operation of the motor according to the detection result of the abnormality detection unit, It has, The aforementioned abnormal motor control unit, When the abnormality detection unit detects the abnormal condition, it stops the motor's rotation and controls the operation of the output shaft differently from that of the normal condition when an external force is applied to the motor in the rotational direction of the output shaft. Motor control device.

2. In the motor control device according to claim 1, The aforementioned abnormal motor control unit, When the abnormality detection unit detects the abnormal condition, it controls the motor to switch between an output shaft rotatable state, in which the output shaft can rotate due to an external force applied in the rotational direction, and an output shaft rotation-stopped state, in which the output shaft does not rotate even when the external force is applied, depending on the rotation angle of the output shaft, or the elapsed time in either the output shaft rotatable state or the output shaft rotation-stopped state. Motor control device.

3. In the motor control device according to claim 1, The aforementioned abnormality detection unit detects multiple types of abnormal conditions, The aforementioned abnormal motor control unit, When the abnormality detection unit detects one of the multiple types of abnormal conditions, the motor is controlled to perform different operations on the output shaft when an external force is applied in the rotational direction of the output shaft, depending on the type of abnormal condition. Motor control device.

4. In the motor control device according to claim 3, The aforementioned abnormal motor control unit, When the abnormality detection unit detects one of the multiple types of abnormal conditions, the motor is controlled to switch between an output shaft rotatable state, in which the output shaft can rotate due to an external force applied in the rotational direction, and an output shaft rotation-stopped state, in which the output shaft does not rotate even when the external force is applied, at different timings depending on the type of abnormal condition, based on the rotation angle of the output shaft or the elapsed time in either the output shaft rotatable state or the output shaft rotation-stopped state. Motor control device.

5. In the motor control device according to claim 4, The aforementioned abnormal motor control unit, When the abnormality detection unit detects one of the multiple types of abnormal conditions, the motor is controlled to switch from the output shaft rotatable state to the output shaft rotation-stopped state at a rotation angle where the number of cogging torques generated when the output shaft rotates due to an external force applied in the rotational direction during the output shaft rotatable state differs according to the type of abnormal condition. Motor control device.

6. In the motor control device according to any one of claims 1 to 5, The circuit further comprises a switching circuit having multiple switching elements that constitute a bridge circuit, and electrically connected to the input and output sides of the motor. The aforementioned abnormal motor control unit, When the abnormality detection unit detects the abnormal condition, it drives a portion of the switching element to temporarily short-circuit the input and output sides of the motor. Motor control device.

7. In the motor control device according to any one of claims 1 to 5, The system further includes a rotation stop unit that, when the abnormality detection unit detects the abnormal condition, is controlled by the abnormal motor control unit to mechanically stop the output shaft without rotating it, even if an external force is applied to the output shaft in the rotational direction. Motor control device.

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