JP5762685B2 - Control rotational speed calculation device, control rotational speed calculation method, and control rotational speed calculation program - Google Patents

Description

  The present invention relates to a control rotational speed calculation device capable of calculating and outputting the most suitable control rotational speed as a control target in order to appropriately control the rotational speed of a rotating body such as a drive shaft of an engine. In particular, the present invention relates to an apparatus for calculating a rotational speed for controlling a rotating body that is less likely to cause unnecessary fluctuations in the operation of the rotating body due to stable control, has a simple configuration, and is low in cost.

  When controlling the rotational speed of the engine, the rotational speed of the rotary shaft is detected by the rotational sensor, and the control means calculates the rotational speed based on the rotational signal from the rotational sensor indicating the rotational speed. As a basis, a technique of controlling the engine speed can be adopted. In such a general control configuration, for example, a general-purpose sensor such as an electromagnetic pickup or a proximity sensor can be used as the rotation sensor used for acquiring the rotation signal. In some cases, there are cases where two or more are used.

  Patent Document 1 listed below discloses a sensor that detects the number of rotations of a rotating body made of a nonmagnetic conductor. This sensor is not a general-purpose sensor. For example, two coils 2 that are electrically parallel and each excites a rotating body, one output terminal 6 that is common to these coils 2, an amplifier 4, and pulse conversion. 5 is provided so that even if one coil is disconnected, the other coil continues to output. As described above, since the sensor includes two coils, it is excellent in reliability even in a harsh environment such as an engine and can detect the rotational speed stably for a long period of time.

JP 2009-162711 A

  However, in the configuration in which the rotation speed is controlled using the general-purpose rotation sensor as described above, when a rotation signal is output by one rotation sensor, an abnormal rotation signal is controlled when a failure occurs in the rotation sensor. There is a problem that the operation of the engine becomes unstable because it is used.

  When two general-purpose rotation sensors are used, it cannot be determined which rotation sensor is correct, and it is difficult to perform stable control. In addition, it is possible to use a method in which one rotation sensor is used as the main and the output of the other sensor is used as a reference, and compared with this, but it must be premised on the possibility of erroneous determination. However, stable control cannot always be realized.

  When three general-purpose rotation sensors are used, the determination accuracy may be improved by making a decision by majority vote, but the cost increases due to the increase in the number of rotation sensors installed, and the configuration and data processing become complicated. There is a problem such as.

  In addition, the sensor described in the above-mentioned Patent Document 1 substantially detects the number of rotations with two sensors (coils), but its configuration does not use a general-purpose sensor as described above. Rather, it is composed of dedicated sensors and circuits. For this reason, there are problems that the manufacturing cost is higher than when a general-purpose sensor is used, and that it cannot be easily incorporated into a conventional system.

  An object of the present invention is to solve the conventional problems as described above, and to realize stable control while being low in cost because of a simple configuration using a general-purpose sensor. An object of the present invention is to provide a rotation speed calculation device for controlling a rotating body that can be used.

The control rotation speed calculation device according to claim 1 is a control rotation speed calculation device that calculates a control rotation speed for controlling the rotation speed of the rotating body.
Two sensors for detecting the number of rotations of the rotating body,
The rotational speed of the rotating body is calculated for each predetermined time interval based on the rotational speeds respectively detected by the two sensors, and the rotational speed by one of the sensors is less than the rotational signal selection determination speed and the other In the first case where the rotation speed by the sensor is equal to or higher than the rotation signal selection determination speed, the control rotation speed is calculated based on the rotation speed by the other sensor, and the first case is established. In the second case where the rotation speed by the other sensor is less than the rotation signal selection determination speed and the rotation speed by one of the sensors is greater than or equal to the rotation signal selection determination speed, the one by the one sensor when the rotational speed for the control is calculated based on the rotational speed, which when the first and the second case is not satisfied, the said two sensors The absolute value of the difference between the current and previous rotation speeds is calculated and compared with each other, and the control rotation speed is determined based on the current rotation speed of the sensor determined to have a smaller absolute value of the difference. It is characterized by comprising a calculation device for calculation .

The control rotational speed detection device according to claim 3 is the control rotational speed detection device according to claim 2,
When the two sensors are normal, the arithmetic unit is configured to rotate the rotation when both of the two abnormality determination rotation speeds based on the rotation speeds of the two sensors are equal to or higher than an overspeed determination speed. It is characterized in that it is determined that the rotational speed of the body is overspeed.

The control rotation speed detection device according to claim 4 is the control rotation speed detection device according to claim 3,
In the arithmetic unit, one of the two sensors is abnormal and the other is normal, and the abnormality determination rotation speed based on the rotation speed of the other sensor is normal or higher than the overspeed determination speed. In some cases, the rotational speed of the rotating body is determined to be overspeed.

The control rotation speed detection device according to claim 5 is the control rotation speed detection device according to claim 4,
In the arithmetic unit, when the rotational speed of one of the two sensors is 0 and the rotational speed of the other is equal to or higher than the disconnection determination speed, the one sensor having the rotational speed of 0 is abnormal. It is characterized by judging.

The control rotational speed calculation method according to claim 5 is a control rotational speed calculation method for calculating a control rotational speed for controlling the rotational speed of a rotating body.
The rotational speed of the rotating body is detected by two sensors, respectively, and the rotational speed of the rotating body is calculated for each predetermined time interval based on the rotational speed detected by the two sensors. In the first case where the rotation speed by the sensor is less than the rotation signal selection determination speed and the rotation speed by the other sensor is greater than or equal to the rotation signal selection determination speed, the control is performed based on the rotation speed by the other sensor. And the first case does not hold, the rotation speed by the other sensor is less than the rotation signal selection determination speed, and the rotation speed by one sensor is greater than or equal to the rotation signal selection determination speed. the second case calculates the rotational speed for the control on the basis of the rotational speed of one said sensor is, when the first and the second case is formed If not, the absolute value of the difference between the current and previous rotation speeds of the two sensors is calculated and compared with each other, and the current rotation speed of the sensors determined to have a small absolute value The control rotational speed is calculated based on the above .

The control rotational speed calculation program according to claim 6 is a control rotational speed calculation program for calculating a control rotational speed for controlling the rotational speed of the rotating body.
The rotational speed of the rotating body is calculated for each predetermined time interval based on the rotational speeds respectively detected by the two sensors that detect the rotational speed of the rotating body, and the rotational speed by one of the sensors is calculated. In the first case where the rotational speed of the other sensor is less than the rotational signal selection determination speed and is equal to or higher than the rotational signal selection determination speed, the control rotational speed is calculated based on the rotational speed of the other sensor. In the second case, the first case does not hold, and the rotation speed by the other sensor is less than the rotation signal selection determination speed and the rotation speed by one sensor is equal to or higher than the rotation signal selection determination speed. on the basis of the rotational speed to calculate the rotational speed for the control, if the case where the first and the second case is not satisfied by one said sensor is in, The absolute value of the difference between the current and the previous rotation speed of the two sensors is calculated and compared with each other, and the absolute value of the difference is determined to be small based on the current rotation speed of the sensor. The control rotational speed is calculated .

According to the control rotational speed calculation device described in claim 1, the control rotational speed calculation method described in claim 5 , and the control rotational speed calculation program described in claim 6 , Effects can be obtained. That is, the rotation speed is acquired by two sensors at predetermined time intervals, the first case where the rotation speed by one sensor is less than the reference value and the rotation speed by the other sensor is more than the reference value, and the second two cases Since the control rotational speed is calculated based on the rotational speed of the larger sensor, the rotational speed of the rotating body is controlled. Therefore, the rotation of the rotating body to be controlled is not destabilized. Further, when the first case and the second case are not established, the control rotational speed is calculated based on the comparison of the absolute value of the difference, so that the sensor is switched for use due to a sensor malfunction. In this case, there is little possibility that the rotation speed of the rotating body suddenly increases and a shock is applied.

  According to the control rotational speed detection device described in claim 3, when the two sensors are normal in the effect of the control rotational speed detection device according to claim 2, the rotational speeds of the two sensors are detected. It is possible to determine whether or not the rotational speed of the rotating body is overspeed by comparing the two rotational speeds for abnormality determination based on each of the above and the reference value. Can be suppressed.

  According to the control rotation speed detection device described in claim 4, in the effect of the control rotation speed detection device according to claim 3, when one of the two sensors is abnormal and the other is normal, By comparing the rotation speed for abnormality determination based on the rotation speed of the normal sensor with the reference value, it is possible to determine whether or not the rotation speed of the rotation body is overspeed. Increase can be suppressed.

  According to the control rotational speed detection device described in claim 5, in the effect of the control rotational speed detection device according to claim 4, the rotational speed by one sensor is 0, and the rotational speed by the other sensor is When the value is equal to or greater than the reference value, it is determined that the sensor having the rotation speed of 0 is abnormal, so that it is possible to correctly determine the disconnection status of the two sensors.

It is a block diagram which shows the structure of the rotational speed calculation apparatus for control which concerns on embodiment of this invention. It is a wave form diagram of a signal in a rotation speed calculation device for control concerning an embodiment of the present invention, and is a wave form diagram showing a rotation signal from a sensor, and a rotation signal obtained by shaping this with an arithmetic unit. FIG. 2 is a block diagram illustrating an internal configuration of a CPU included in the arithmetic device and a flow of information in the CPU in the control rotation speed calculation device according to the embodiment of the present invention. 6 is a flowchart illustrating an information processing procedure in a selector of a CPU included in an arithmetic device in the control rotation speed calculation device according to the embodiment of the present invention. 6 is a flowchart illustrating an information processing procedure for performing an overspeed determination process in a CPU included in an arithmetic device in the control rotation speed calculation device according to the embodiment of the present invention. 7 is a flowchart illustrating an information processing procedure for performing rotation sensor disconnection determination processing by a CPU included in an arithmetic device in the control rotation speed calculation device according to the embodiment of the present invention.

An embodiment of the present invention will be described with reference to FIGS.
(1) Explanation of terms Table 1 shows the names and symbols and the meanings of the components and various speeds of the apparatus used in the following explanation prior to the explanation.

(2) Configuration The control rotation speed calculation device 10 according to the embodiment shown in FIG. 1 is intended for a rotating body such as an engine drive shaft 11 and is close to a detection gear 12 that is linked to the drive shaft 11. Two general-purpose sensors 1 and 2 are arranged, and the arithmetic device 3 performs processing according to a predetermined procedure (program) determined in advance using the rotation signals obtained from the sensors 1 and 2 as input information to control the engine. This is a device that generates, as output information, a rotation speed output of the drive shaft 11 (control rotation speed NEa) and an alarm output such as a speed over or disconnection of the sensors 1 and 2 most suitable for the output. The rotational speed output (control rotational speed NEa) calculated by the control rotational speed calculation device 10 and output to the outside and the alarm output are given to an engine control device not shown in FIG. It will be used for control (or rotational speed control).

  As shown in FIG. 1, in the vicinity of the detection gear 12 attached to the drive shaft 11 of the engine, two general-purpose sensors 1, 2 such as an electromagnetic pickup and a proximity sensor are provided close to the teeth of the detection gear 12. Is arranged as a rotation sensor. These two sensors 1 and 2 detect the teeth of the detection gear 12 and output rotation signals as shown in the upper part of FIG. The rotation signals from the two sensors 1 and 2 are input to two waveform shaping circuits 4 and 5 provided in the arithmetic unit 3 corresponding to the sensors 1 and 2 as shown in FIG. Then, it is shaped into a rectangular rotation signal as shown in the lower part of FIG.

(3) Calculation processing of control rotational speed NEa As shown in FIG. 1, in the arithmetic unit 3, the rotation signals after shaping output from the waveform shaping circuits 4 and 5 are inputted to the CPU 6 and will be described next. Receive internal processing. First, the procedure for calculating the control rotational speed NEa will be described with reference to FIGS. 1, 3 and 4. As shown in FIG. 1, the rotation signals output from the sensors 1 and 2 are respectively shaped by the waveform shaping circuits 4 and 5 as described above and then inputted to the CPU 6. The CPU 6 inputs the rotation signal after shaping to a counter (not shown) in the CPU 6 and measures the time of the pulse interval of the rotation signal by generating an interrupt or reading the counter value periodically, and the instantaneous rotation speed NE1, Convert to NE2.

  As shown in FIG. 3, in the CPU 6, moving average processing is performed on the instantaneous rotational speeds NE1 and NE2, respectively, and abnormality determining rotational speeds NE1a and NE2a are calculated. In the CPU 6, the selector 7 selects one of the instantaneous rotational speeds NE1 and NE2 as the rotational speed NE, and performs a moving average process on the rotational speed NE to calculate the control rotational speed NEa.

FIG. 4 shows a selection procedure of the instantaneous rotational speeds NE1 and NE2 in the selector 7 shown in FIG. In this selection, the rotation signal selection determination speed V _S is used as a reference value, and this is compared with the instantaneous rotation speeds NE1 and NE2. As shown in FIG. 4, when the rotation speed selection start procedure is started in the selector 7, first, the conditions NE1 <V _S and V _S ≦ NE2 are determined in step S11. ) As the rotation speed NE, select a larger NE2 instead of the NE1 smaller than the rotation signal selection determination speed V _S (S12), and the selection process ends. If the condition of step S11 is not satisfied (S11, NO), the condition of NE2 <V _S and V _S ≦ NE1 is determined in step S13. If the condition is satisfied (S13, YES), the rotation speed NE is set as the rotation speed. Large NE1 is selected instead of NE2 smaller than the signal selection determination speed V _S (S14), and the selection process is terminated.

If the condition of step S13 is not satisfied (S13, NO), the condition of equation (A) is determined in step S15. Here, the equation (A) is as shown in the following equation as shown in FIG.
| NE1 (n) −NE1 (n−1) | ≦ | NE2 (n) −NE2 (n−1) | (A) (n: current value, n−1: previous value)

  Judging whether or not the formula (A) is satisfied is to calculate the absolute value of the difference between the current and the previous instantaneous rotational speed of the two sensors 1 and 2 and compare them with each other, and the temporal difference between them. This means that the current instantaneous rotation speed of the sensor whose absolute value is determined to be small is selected as the rotation speed. Therefore, when the formula (A) is satisfied (S15, YES), the absolute value of the difference is the instantaneous rotational speed NE1 by the sensor 1, so the instantaneous rotational speed NE1 is selected as the rotational speed NE ( S16), the selection process is terminated. If the formula (A) is not satisfied (S15, NO), the absolute value of the difference is the instantaneous rotational speed NE2 by the sensor 2, so the instantaneous rotational speed NE2 is selected as the rotational speed NE (S17). The selection process is terminated.

  Thus, according to this embodiment, when the rotation speed by one sensor is less than the reference value and the rotation speed by the other sensor is more than the reference value, the larger rotation speed is selected and moved. The control rotational speed NEa is averaged, and in other cases, the absolute values of the difference between the current rotational speed and the previous rotational speed of the two sensors are compared with each other, and the smaller absolute value of the difference is smaller. The current rotational speed by the sensor is selected, and a moving average of the selected rotational speeds is taken as the control rotational speed NEa. Therefore, in order to control the rotational speed of the engine, even if one sensor malfunctions and switches to the other sensor, a shock such as a sudden increase in the rotational speed of the engine is unlikely to occur, and the shock is almost smooth. Therefore, the sensor can be switched, and there is little possibility that the rotation of the engine to be controlled becomes unstable.

(4) Overspeed Determination Processing In the arithmetic device 3 shown in FIG. 1, overspeed determination processing is performed in the CPU 6. Overspeed determination process for determining abnormality speed NE1a shown in FIG. 3, uses a NE2a, overspeed determination speed V _OVER as a reference value, carried out in the procedure shown in FIG.

As shown in FIG. 5, when the overspeed determination process is started, it is first determined in step S21 that the sensor 1 is not disconnected (S21, NO), and in step S22, it is determined that the sensor 2 is not disconnected (S22). , NO), if all the sensors are normal, in step 23, the conditions of V _OVER ≦ NE1a and V _OVER ≦ NE2a are determined. If it is established (S23, YES), an alarm is output as an overspeed has occurred (S24), and the determination process is terminated. If V _OVER ≦ NE1a and V _OVER ≦ NE2a are not satisfied (S23, NO), no overspeed has occurred, so this determination process is terminated without outputting an alarm.

As shown in FIG. 5, after the overspeed determination process is started, if it is first determined in step S21 that the sensor 1 is disconnected (S21, YES), the sensor 2 is not disconnected as described later. Therefore, the rotational speed NE2a for abnormality determination by the sensor 2 is adopted as the rotational speed N (S25), and the condition of V _OVER ≦ N is determined in step 26. If it is established (S26, YES), the abnormality determination rotational speed NE2a of the normal sensor 2 exceeds the reference value, so an alarm is output as an overspeed has occurred (S24), The determination process ends. If the condition of V _OVER ≦ N is not satisfied in step 26 (S26, NO), the normal determination abnormality speed NE2a of the sensor 2 is lower than the reference value, and thus no overspeed has occurred. First, this determination process is terminated without outputting an alarm.

As shown in FIG. 5, after the overspeed determination process is started, if it is determined in step S21 that the sensor 1 is not disconnected (S21, NO), whether or not the sensor 2 is disconnected in step S22. Is judged. If it is determined that the sensor 2 is disconnected (S22, YES), the abnormality determination rotational speed NE1a by the sensor 1 is adopted as the rotational speed N (S27), and the condition of V _OVER ≦ N is satisfied in step 26. To be judged. If it is established (S26, YES), the abnormality determination rotational speed NE1a of the normal sensor 1 exceeds the reference value, so an alarm is output as an overspeed has occurred (S24), The determination process ends. If the condition of V _OVER ≦ N is not satisfied in step 26 (S26, NO), the abnormal speed of rotation NE1a of the normal sensor 1 is below the reference value, so no overspeed has occurred. First, this determination process is terminated without outputting an alarm.

  Thus, according to the present embodiment, when the two sensors are normal, the two abnormality determination rotational speeds NE1a and NE2a respectively corresponding to the rotational speeds of the two sensors are compared with the reference value. Thus, it is possible to determine whether or not the engine rotational speed is overspeed. When one of the two sensors is abnormal and the other is normal, the abnormality determination is based on the normal sensor rotational speed. By comparing the rotational speed NE1a or NE2a with the reference value, it can be determined whether or not the rotational speed of the engine is overspeed. For this reason, it can suppress that the rotational speed of an engine raises in an abnormal state. If the engine goes out of control due to some abnormality and overspeeds, it may cause a serious accident. However, according to the present embodiment, such an abnormality is detected early and stopped in a safe and prompt manner. There is an effect that can be.

(5) Rotation sensor disconnection determination process In the overspeed determination process of FIG. 5 described above, the presence or absence of disconnection of the sensors 1 and 2 is determined. The determination process for the disconnection of the sensor is performed by the arithmetic device 3 shown in FIG. in the CPU 6, the abnormality determination rotational speed NE1a shown in FIG. 3, uses a NE2a, disconnection determination speed V _err is the reference value, performing the procedure shown in FIG.

As shown in FIG. 6, after the disconnection determination processing of the sensors 1 and 2 is started, first, in step S31, the conditions of NE1a = 0 and V _err ≦ NE2a are determined, and if it is determined that the conditions are satisfied, (S31, YES), since the output of the sensor 1 is 0, the sensor 2 indicates a rotational speed equal to or higher than the reference value, so an alarm is output that the sensor 1 is disconnected (S32). The determination process is terminated.

As shown in FIG. 6, after the sensor disconnection determination process is started, if it is determined in step S31 that the condition of NE1a = 0 and V _err ≦ NE2a is not satisfied (S31, NO), in step S33. A condition of NE2a = 0 and V _err ≦ NE1a is determined. When it is determined that the same condition is satisfied (S33, YES), the output of the sensor 2 is 0, but the sensor 1 indicates a rotational speed that is equal to or higher than the reference value, so the sensor 2 is disconnected. Is output (S34), and the determination process is terminated.

If it is determined in step S31 that the condition of NE1a = 0 and V _err ≦ NE2a is not satisfied (S31, NO), and it is determined in step S33 that the condition of NE2a = 0 and V _err ≦ NE1a is not satisfied (S33, NO) Both of the two sensors are determined to be normal (S35), and this determination process is terminated without outputting an alarm.

  Thus, according to this embodiment, when the rotation speed by one sensor is 0 and the rotation speed by the other sensor is equal to or higher than the reference value, the sensor having the rotation speed of 0 is abnormal. Therefore, it is possible to correctly determine the disconnection status of the two sensors.

  As described above, the control rotation speed calculation device 10 according to the present embodiment is configured by writing a program describing the information processing procedure represented by the flowcharts shown in FIGS. 4 to 6 in the ROM of the arithmetic device 3. In this type of information processing apparatus, the CPU 6 processes the rotation signals from two general-purpose sensors installed independently of each other together with the RAM or the like in accordance with the program in the ROM, whereby the control rotational speed NEa or The abnormality determination rotational speeds NE1a and NE2a are calculated and output to the outside, and the engine control is stably performed using the rotation speeds, and abnormality determination such as overspeed determination or sensor disconnection determination is performed. To achieve this goal.

In each of the selection / determination processing procedures in the arithmetic device 3 described above, the rotation signal selection determination speed V is used as a reference value for comparison with various rotation speeds based on the output of the sensor according to the purpose of the processing. _S , overspeed determination speed V _OVER , and disconnection determination speed V _err are set in advance. The magnitude relationship can generally be V _err ≦ V _S <V _OVER .

  Further, the control rotational speed calculation device 10 of the present embodiment calculates the control rotational speed for controlling the engine, but this is only an example, and the target for calculating the control rotational speed is as follows. Of course, the present invention is not limited to the engine, and any rotating body capable of detecting the number of rotations and controlling the rotation is the subject of the present invention.

DESCRIPTION OF SYMBOLS 1, 2 ... Sensor 3 ... Arithmetic unit 4, 5 ... Waveform shaping circuit 6 ... CPU
7 ... Selector 10 ... Control rotational speed calculation device

Claims (6)

In the control rotational speed calculation device for calculating the control rotational speed for controlling the rotational speed of the rotating body,
Two sensors for detecting the number of rotations of the rotating body,
The rotational speed of the rotating body is calculated for each predetermined time interval based on the rotational speeds respectively detected by the two sensors, and the rotational speed by one of the sensors is less than the rotational signal selection determination speed and the other In the first case where the rotation speed by the sensor is equal to or higher than the rotation signal selection determination speed, the control rotation speed is calculated based on the rotation speed by the other sensor, and the first case is established. In the second case where the rotation speed by the other sensor is less than the rotation signal selection determination speed and the rotation speed by one of the sensors is greater than or equal to the rotation signal selection determination speed, the one by the one sensor when the rotational speed for the control is calculated based on the rotational speed, which when the first and the second case is not satisfied, the said two sensors The absolute value of the difference between the current and previous rotation speeds is calculated and compared with each other, and the control rotation speed is determined based on the current rotation speed of the sensor determined to have a smaller absolute value of the difference. control revolution speed calculation apparatus characterized by comprising an arithmetic unit for calculating. When the two sensors are normal, the arithmetic unit is configured to rotate the rotation when both of the two abnormality determination rotation speeds based on the rotation speeds of the two sensors are equal to or higher than an overspeed determination speed. body the rotational speed control revolution speed detecting apparatus according to claim 1, wherein determining that an over speed. In the arithmetic unit, one of the two sensors is abnormal and the other is normal, and the abnormality determination rotation speed based on the rotation speed of the other sensor is normal or higher than the overspeed determination speed. 3. The control rotational speed detection device according to claim 2 , wherein the rotational speed of the rotating body is determined to be an overspeed in some cases. In the arithmetic unit, when the rotational speed of one of the two sensors is 0 and the rotational speed of the other is equal to or higher than the disconnection determination speed, the one sensor having the rotational speed of 0 is abnormal. The rotational speed detection device for control according to claim 3, wherein: In the control rotational speed calculation method for calculating the control rotational speed for controlling the rotational speed of the rotating body,
The rotational speed of the rotating body is detected by two sensors, respectively, and the rotational speed of the rotating body is calculated for each predetermined time interval based on the rotational speed detected by the two sensors. In the first case where the rotation speed by the sensor is less than the rotation signal selection determination speed and the rotation speed by the other sensor is greater than or equal to the rotation signal selection determination speed, the control is performed based on the rotation speed by the other sensor. And the first case does not hold, the rotation speed by the other sensor is less than the rotation signal selection determination speed, and the rotation speed by one sensor is greater than or equal to the rotation signal selection determination speed. the second case calculates the rotational speed for the control on the basis of the rotational speed of one said sensor is, when the first and the second case is formed If not, the absolute value of the difference between the current and previous rotation speeds of the two sensors is calculated and compared with each other, and the current rotation speed of the sensors determined to have a small absolute value The control rotational speed calculation method is characterized in that the control rotational speed is calculated based on the above . In the control rotational speed calculation program for calculating the rotational speed for control for controlling the rotational speed of the rotating body,
The rotational speed of the rotating body is calculated for each predetermined time interval based on the rotational speeds respectively detected by the two sensors that detect the rotational speed of the rotating body, and the rotational speed by one of the sensors is calculated. In the first case where the rotational speed of the other sensor is less than the rotational signal selection determination speed and is equal to or higher than the rotational signal selection determination speed, the control rotational speed is calculated based on the rotational speed of the other sensor. In the second case, the first case does not hold, and the rotation speed by the other sensor is less than the rotation signal selection determination speed and the rotation speed by one sensor is equal to or higher than the rotation signal selection determination speed. on the basis of the rotational speed to calculate the rotational speed for the control, if the case where the first and the second case is not satisfied by one said sensor is in, The absolute value of the difference between the current and the previous rotation speed of the two sensors is calculated and compared with each other, and the absolute value of the difference is determined to be small based on the current rotation speed of the sensor. A control rotation speed calculation program for calculating a control rotation speed.

Images