JP5018793B2 - Rotational speed measuring device - Google Patents

Description

  The present invention relates to a rotational speed measurement device that obtains an angular movement amount by detecting a rotational position of a rotor of a motor by an electrical angle, and obtains a rotational speed of the motor by calculation using the angular movement amount.

  Conventionally, when the rotational speed of the motor is obtained, the amount of angular movement of the rotor is used. However, a method has been adopted in which the angle of movement of the rotor is detected by a rotational angle detection sensor such as a resolver. FIG. 1 shows a flowchart representing the operation of a conventional rotational speed measurement process, and will be described. However, it is assumed that a resolver is used as a motor rotation angle detection sensor.

  In step S1, the motor rotor angle (angle acquisition function) detected by the resolver is used as angle data. In step S2, the angle movement amount within a fixed time is obtained by subtracting the previously obtained angle data (previous angle data) from the angle data at a certain fixed time.

  In step S3, it is determined whether or not the amount of angular movement is smaller than −180 ° (degrees). In FIG. 2, it is determined whether or not the rotor has straddled the 0-point or the 360-degree reference position of point a. For example, if the angular movement amount is a point e of 100 ° that is 160 ° away from the s point (300 °) in the positive rotation direction, the angular movement amount obtained in step S2 is (100 ° −300 ° =) − 200 °. It becomes. Then, since the determination result in step 3 is Yes, the process proceeds to step S4. In FIG. 2, the horizontal axis represents the rotation angle, and the vertical axis represents the resolver detection value such as a count value corresponding to the rotor angle detected by the resolver.

  In step S4, 360 ° is added to the angular movement amount to obtain an angular movement amount fix. When the amount of angular movement is −200 °, −200 ° + 360 ° = 160 °. In other words, if the angle movement amount calculated in step S2 using the detected angle data is used as it is, when the angle data over 0 ° or 360 ° of point a is obtained, a desired angle movement amount is obtained. Therefore, 360 ° is added to obtain the actual movement amount.

  Next, in step S5, the angle data obtained in step S1 is processed as the previous angle data. In step S6, the rotational speed of the rotor is obtained by calculation from the following equation (1) using the angular movement amount fix of 160 ° obtained in step S4.

Rotational speed = (ΔCn / Cmax) × (2π / m) × (1 / Δt) (1)
However, ΔCn is the amount of angular movement, Cmax is the amount of angular movement of 360 °, m is an integer value represented by (mechanical angular period / electrical angular period), and Δt is the amount of temporal movement. o
On the other hand, in step S3, assuming that the point s (300 °) is 160 ° away from the point e (100 °) in the negative rotation direction, the amount of angular movement obtained in step 2 is (300 ° -100 ° =). 200 °. Then, since a determination result is No, it progresses to step S7.

  In step S7, it is further determined whether or not the amount of angular movement is greater than 180 °. If the angle movement amount is 200 °, the determination result is Yes. In step S8, 360 ° is subtracted from the angle movement amount 200 ° to obtain an angle movement amount fix. That is, since 200 ° −360 ° = −160 °, the point −d is −160 ° away from the point a.

  Next, in step S5, the angle data obtained in step S1 is processed as the previous angle data. In step S6, −160 ° of the angular movement amount fix obtained in step S8 is expressed by the above equation (1). Fitting and obtaining the rotational speed of the rotor by calculation.

  Furthermore, in step S3, for example, if the amount of angular movement is point e, which is 100 degrees away from point a in the forward rotation direction, the determination result is No, so the process proceeds to step S7. In step S7, it is further determined whether or not the amount of angular movement is greater than 180 °. In this case, since the angular movement amount is 100 °, the determination result is No, and in step S9, a process of setting the angular movement amount 100 ° as the angular movement amount fix is performed. Next, in step S5, the angle data obtained in step S1 is processed as the previous angle data. In step S6, −100 ° of the angular movement amount fix obtained in step S9 is expressed by the above equation (1). Fitting and obtaining the rotational speed of the rotor by calculation.

  With such a method for obtaining the rotational speed, the rotational direction cannot be obtained if the angular movement exceeds 180 °. That is, it is restricted by the amount of angular movement for 180 °, and it is impossible to calculate a region having a higher rotational speed. In other words, there is a drawback that the rotational speed with the rotational direction cannot be calculated unless the angular movement amount is within 180 °. As a technique for compensating for this drawback, there is a rotational speed measuring device described in Patent Document 1.

  This rotational speed measuring device calculates the rotational speed by the method described above during low-speed rotation and holds information on the rotational direction. When the rotational speed region is reached, the rotational direction information is used to calculate the amount of angular movement within a certain time period by 360. The rotation speed detection range is expanded up to the angle movement amount of °. The operation of the rotational speed measurement process will be described with reference to the flowcharts shown in FIGS. 3 and 4, the same parts as those in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

  After obtaining the angular movement amount in step S2 shown in FIG. 3, in step S11, it is determined from the angular movement amount whether or not the rotational speed of the motor is a low speed rotation that is a predetermined rotational speed. As a result, if the rotation speed is low, the process proceeds to step S3. Here, steps S3 and S4 or steps S7, S8, and S9 are performed to determine the angular movement amount fix.

  Next, in step S12, it is determined whether or not the angular movement amount fix is 0 ° or more. If the angle is 0 ° or more, it is determined as normal rotation in step S13. If it is smaller than 0 °, it is determined that the rotation is negative in step S14. Thereafter, in step S5, the angle data obtained in step S1 is processed as the previous angle data. In step S15, the angular movement amount fix obtained above is applied to the above equation (1), and the rotor The rotational speed is obtained by calculation. At this time, since it is known whether the rotation is positive or negative, the rotation speed with the rotation direction is obtained.

  On the other hand, if it is determined in step S11 that the rotation is not low speed, in other words, if it is determined that the rotation is high speed, the process proceeds to step S21 shown in FIG. In step S21, it is determined whether or not the rotor is rotating forward. This determination is performed by the positive rotation or the negative rotation determined in steps S12 to S14.

  For example, if it is determined that the rotation is normal, it is determined in step S22 whether or not the amount of angular movement is smaller than 0 °. For example, if the amount of angular movement is the s point-y point shown in FIG. 2, (200 ° −300 ° =) − 100 ° and the determination result is Yes, so the process proceeds to step S23.

  In step S23, 360 ° is added to the angular movement amount −100 ° to perform an angle movement amount fix = 260 °. Thereafter, in step S5 shown in FIG. 3, the angle data obtained in step S1 is processed as the previous angle data. In step S15, the angular movement amount fix = 260 ° is applied to the above equation (1), and the rotation is performed. The rotation speed of the child is obtained by calculation. At this time, the rotational speed at the forward rotation is obtained.

  If it is determined in step S22 that the angular movement amount is not smaller than 0 °, that is, the angular movement amount is, for example, 190 ° and 0 ° or more, the angular movement amount 190 ° is converted into the angular movement amount in step S24. Processing to fix is performed. Thereafter, the angle data is processed as the previous angle data in step S5, and the angular movement amount fix = 190 ° is applied to the above equation (1) in step S15 to obtain the rotation speed in the normal rotation.

On the other hand, if it is determined in step S21 that the rotation is not positive, that is, if it is determined that the rotation is negative, it is determined in step S25 whether or not the angular movement amount is 0 ° or more. For example, if the amount of angular movement is the d point-s point shown in FIG. 2, (300 ° -190 °) = 110 ° , and the determination result is Yes, so the process proceeds to step S26.

In step S26, 360 ° is subtracted from the angular movement amount 100 ° to perform processing for setting the angular movement amount fix = −260 °. Thereafter, the angle data is processed as the previous angle data in step S5, and the angular movement amount fix = −260 ° is applied to the above equation (1) in step S16 to obtain the rotation speed in the negative rotation.

If it is determined in step S25 that the angular movement amount is not 0 ° or more, that is, the angular movement amount is −190, for example, smaller than 0 °, in step S27, the angular movement amount −190 ° is changed to the angular movement amount. Processing to fix is performed. Thereafter, the angle data is processed as the previous angle data in step S5, and the angular movement amount fix = −190 ° is applied to the above equation (1) in step S16 to obtain the rotation speed in the negative rotation.

  Thus, by calculating the rotation speed and maintaining the rotation direction during low-speed rotation, the rotation speed is calculated without worrying about the rotation direction during high-speed rotation, and finally the previously determined rotation direction is added. Thus, the rotation speed with the rotation direction can be obtained.

JP 2008-164335 A

  However, in Patent Document 1 described above, the number of rotations with a rotation direction can be calculated if the amount of angular movement within a certain time is within 360 °. In other words, there is a problem that the rotational speed cannot be measured unless the amount of angular movement within a certain time is within 360 °. That is, when the rotational speed of the motor is a super high speed rotation that is equal to or higher than a predetermined value, the rotational speed detected by the resolver within a predetermined time exceeds 360 °, and in this case, the rotational speed cannot be measured.

  The present invention has been made in view of such circumstances, and even if the amount of angular movement of the rotor detected within a predetermined time by the rotation angle detection sensor of the motor is an ultra-high speed rotation exceeding 360 °, the present invention can be rotated. An object of the present invention is to provide a rotational speed measuring device capable of measuring a speed.

  The invention according to claim 1, which has been made to achieve the above object, detects the rotational position of 0 ° to 360 ° of a rotating body that rotates forwardly or negatively reversely by an electrical angle, and corresponds to the electrical angle. A rotation angle detection sensor that outputs an angle detection value that is an integer value to be calculated, and an angle movement amount that is a movement amount of the angle detection value output from the rotation angle detection sensor within a certain period of time is obtained. And a rotational speed measuring device having a rotational speed calculating means for obtaining the rotational direction and rotational speed of the rotating body, wherein the rotational speed calculating means has a difference of 180 ° between the previous angular movement amount and the current angular movement amount. When the angle is exceeded, it is determined that the rotating body has exceeded the angle of 360 ° on the positive rotation side. At this time, the angle of 360 ° is added to the current angular movement amount, and the result of the addition is calculated as the rotation speed. The amount of angular movement used to find It is characterized by that.

  According to this configuration, even if the amount of angular movement of the rotating body detected within a predetermined time by the rotation angle detection sensor is a super high speed rotation exceeding 360 ° on the positive rotation side, the rotation speed is not reduced without reducing the angle detection accuracy. Can be measured.

  According to a second aspect of the present invention, in the rotational speed measuring device according to the first aspect, when the rotational speed calculating means determines that the rotational body has exceeded an angle of 360 ° to the positive rotation side, The number of times exceeding the angle of ° is held, and the value obtained by multiplying the number of times of holding by the angle of 360 ° is the angle movement that is the amount of movement of the angle detection value output from the rotation angle detection sensor within a predetermined time. The amount is added to the amount to obtain a new amount of angular movement.

  According to this configuration, the number of times that the rotating body exceeds the angle of 360 ° is held, and a value obtained by multiplying the number of times of holding by the angle of 360 ° is added to the next obtained angle moving amount, thereby obtaining a new angular moving amount. I tried to do it. Therefore, even if the rotating body changes from high-speed rotation to higher-speed ultra-high-speed rotation, the amount of angular movement at this time can be obtained appropriately.

According to a third aspect of the present invention, in the rotational speed measuring device according to the first aspect, the rotational speed calculating means is configured such that the difference between the previous angular movement amount and the current angular movement amount exceeds an angle of −180 °. In this case, it is determined that the rotating body has exceeded the 360 ° angle on the negative rotation side, and at this time, an angle of −360 ° is added from the current angular movement amount , and this result is used to obtain the rotational speed. It is characterized by the amount of angular movement used.

  According to this configuration, even if the amount of angular movement of the rotating body detected within a predetermined time by the rotation angle detection sensor exceeds 360 ° on the negative rotation side, the rotation speed can be increased without reducing the angle detection accuracy. It can be measured.

  According to a fourth aspect of the present invention, in the rotational speed measurement device according to the third aspect, when the rotational speed calculation means determines that the rotating body has exceeded an angle of 360 ° to the negative rotation side, the negative speed is calculated. The number of times the angle exceeding 360 ° is held on the rotation side, and a value obtained by multiplying the number of times held by the angle of 360 ° is the amount of movement of the angle detection value output from the rotation angle detection sensor within a fixed time. It is characterized by adding to the amount of angular movement which is a new amount of angular movement.

  According to this configuration, the number of times that the rotating body exceeds the 360 ° angle on the negative rotation side is held, and a value obtained by multiplying the number of holding times by the 360 ° angle is added to the next obtained angular movement amount to newly The amount of angular movement was set to a proper value. Therefore, even if the rotating body changes from high-speed rotation to higher-speed ultra-high-speed rotation, the amount of angular movement at this time can be obtained appropriately.

  As described above, according to the present invention, it is possible to measure the rotational speed even when the angular movement amount of the rotor detected within a certain time by the rotational angle detection sensor of the motor exceeds 360 °. There is an effect that can be done.

It is a flowchart showing the operation | movement of the conventional rotational speed measurement process. It is a figure which shows the rotation angle of the rotor of the motor at the time of the conventional rotational speed measurement process. It is a 1st flowchart showing operation | movement of the other conventional rotational speed measurement process. It is a 2nd flowchart showing operation | movement of the other conventional rotational speed measurement process. It is a block diagram which shows the structure of the rotational speed measuring apparatus which concerns on embodiment of this invention. It is a 1st flowchart showing operation | movement of the rotational speed measurement process of this embodiment. It is a 2nd flowchart showing operation | movement of the rotational speed measurement process of this embodiment. It is a 1st figure which shows the rotation angle of the rotor of the motor at the time of the rotational speed measurement process of this embodiment. It is a 2nd figure which shows the rotation angle of the rotor of the motor at the time of the rotational speed measurement process of this embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. However, parts corresponding to each other in all the drawings in this specification are denoted by the same reference numerals, and description of the overlapping parts will be omitted as appropriate.

  FIG. 5 is a block diagram showing the configuration of the rotational speed measuring device according to the embodiment of the present invention.

  A rotational speed measuring apparatus 10 shown in FIG. 5 includes a resolver 12 that is a rotational angle detection sensor provided on a rotor (rotary body) of a motor 11 and a rotational speed calculation circuit 13. The resolver 12 detects the rotational position of the rotor of the motor 11 by an electrical angle, and outputs this to the rotational speed calculation circuit 13 as an integer value (resolver detection value) such as a count value. The rotation speed calculation circuit 13 performs a rotation speed measurement process for calculating a change in electrical angle from a change amount of a resolver detection value that is rotation angle information within a certain time and calculating a rotation direction and a rotation speed of the motor 11. It is.

  The rotational speed measurement process performed by the rotational speed calculation circuit 13 will be described with reference to FIGS.

  First, in step S31 shown in FIG. 6, the angle of the rotor of the motor (angle acquisition function) detected by the resolver 12 is used as angle data (angle detection value). In step S32, the angle movement amount is obtained by subtracting the previous angle data obtained last time from the angle data within a certain fixed time. Next, in step S33, it is determined whether or not the rotation speed of the motor 11 is a low-speed rotation that is a predetermined rotation speed from the angular movement amount. In this determination, for example, a threshold value for determining low-speed rotation and high-speed rotation is associated with the angular movement amount, and if the angular movement amount obtained in step S32 is less than the threshold value, low-speed rotation is performed. It is determined to be rotating.

  As a result, for example, if the rotation speed is low, the process proceeds to step S34. In step S34, it is determined whether or not the amount of angular movement is smaller than −180 °. In FIG. 8, it is determined whether or not the rotor has crossed the reference position of 0 or 360 ° of point a, for example.

  However, in FIG. 8, the horizontal axis is the rotation angle, and when the position of 0 or 360 ° of point a on the horizontal axis is set as the reference position, the motor 11 rotates in the clockwise direction in which the rotor rotates clockwise. The negative rotation direction that rotates counterclockwise is indicated by an arrow. Further, the vertical axis represents a resolver detection value such as a count value corresponding to the rotor angle of the motor 11 detected by the resolver 12.

  For example, if the resolver detection value detected in step S31 is an e point of 100 ° that is 160 ° away from the s point (300 °) in the forward rotation direction, the amount of angular movement obtained in step S32 in this case Is 100 ° −300 ° = −200 °.

  In this case, since the determination result of step S34 is Yes, the process proceeds to step S35. In step S35, 360 ° is added to the angular movement amount to obtain an angular movement amount fix. When the amount of angular movement is −200 °, −200 ° + 360 ° = 160 °. Next, in step S36, it is determined whether or not the angular movement amount fix = 160 ° is equal to or greater than 0 °. If the angle is 0 ° or more, it is determined as normal rotation in step S37. If it is smaller than 0 °, it is determined that the rotation is negative in step S38. Here, since fix = 160 °, it is determined to be normal rotation.

  Next, in step S39, the angle data 300 ° obtained in step S31 is set to the previous angle data = 300 °. In step S40, the angular movement amount fix = 160 ° obtained in step S35 is set to the previous angle data. Processing to make the movement amount. In step S41, the rotational speed of the rotor in the normal rotation is obtained by calculation from the above-described equation (1) using the angular movement amount fix 160 ° obtained in step S35.

On the other hand, in step S34, if the amount of angular movement is, for example, the s point (300 °) that is 160 ° away from the point e (100 °) in the negative rotation direction, the angular movement amount obtained in step 32 is (300 °). −100 ° =) 200 °. Since the determination result in this case is No, the process proceeds to step S42. In step S42, it is further determined whether or not the amount of angular movement is greater than 180 °. Here, since the angular movement amount is 200 °, the determination result is Yes. In step S43, 360 ° is subtracted from the angular movement amount 200 ° to obtain an angular movement amount fix. That is, since 200 ° -360 ° = −160 °, the point s is −160 ° away from the point e .

  Next, in step S36, it is determined whether or not the angular movement amount fix = −160 ° is equal to or greater than 0 °. Here, since fix = −160 °, it is not greater than 0, and therefore it is determined that the rotation is negative in step S38. Then, through the processing of steps S39 and S40, in step S41, the rotational speed of the negative rotation of the rotor is obtained by calculation from the above equation (1) using −160 ° of the angular movement amount fix.

In step S34, for example, if the amount of angular movement is point e which is 100 degrees away from point a in the forward rotation direction, the determination result is No, and the process proceeds to step S42. In step S42, it is further determined whether or not the angular movement amount 100 ° is larger than 180 °. The determination result is No, and in step S44, processing is performed to set the angular movement amount 100 ° to the angular movement amount fix = 100 °. Next, since the angle movement amount fix = 100 ° is 0 ° or more in step S36, it is determined that the rotation is normal rotation in step S37, and after further processing in steps S39 and S40, in step S41, using 100 ° of the angle movement amount fix. The rotational speed of the positive rotation of the rotor is obtained by calculation from the above equation (1).

  On the other hand, if it is determined in step S33 that the rotation is not low speed, in other words, if it is determined that the rotation is high speed, the process proceeds to step S45 shown in FIG. In step S45, it is determined whether or not the rotor is rotating forward. This determination is performed by the positive rotation or the negative rotation determined in the above-described steps S36 to S38 in the previous rotation speed measurement process.

  For example, if it is determined that the rotation is normal, it is determined in step S46 whether or not the amount of angular movement is smaller than 0 °. For example, if the amount of angular movement is the s point−y point, (200 ° −300 ° =) − 100 ° and the determination result is Yes, so the process proceeds to step S47. In step S47, 360 ° is added to the angular movement amount −100 ° to perform an angle movement amount fix = 260 °.

  In the determination in step S46, for example, if the angular movement amount is 190 °, the determination result is No and the process proceeds to step S48, where the angular movement amount 190 ° is set to the angular movement amount fix = 190 °. I do.

On the other hand, if it is determined in step S45 that the rotation is not positive, that is, if it is determined that the rotation is negative, it is determined in step S49 whether or not the angular movement amount is 0 ° or more. For example, if the amount of angular movement is d point-y point, (200 ° -190 ° =) 10 ° and the determination result is Yes, so in step S50, 360 ° is subtracted from the angular movement amount of 100 ° to move the angle. A process of setting the quantity fix = −260 ° is performed. In step S49, for example, when the amount of angular movement is -190 °, the determination result is No. Therefore, in step S51, processing for setting the angular movement amount -190 to angular movement amount fix = -190 ° is performed.

  After any one of these steps S47, S48, S50, and S51, in step S52, the angular movement amount fix is obtained from an equation of angular movement amount fix + number exceeding 360 ° × 360 °. However, the number exceeding 360 ° means the number of angular movements exceeding 360 °, “1” when exceeding the first 360 ° once, and “2” when exceeding the second 360 °. It is an integer value that increases as follows, and is obtained in step S55 or S58 described later.

For example, in step S52, when the number of degrees exceeding 360 ° is 0, if the angle movement amount fix = 170 °, the angle movement amount fix = 170 °. In this case, in Step S53, Δangle movement amount = 189 ° is obtained by subtracting the angle movement amount fix = 170 ° from the previous angle movement amount (for example, 359 °). In step S54, it is determined whether or not Δangle movement amount = 189 ° is larger than 180 °. In this example, since the determination result is Yes, in step S55, the number exceeding 360 ° is obtained from the equation (previous angle movement amount + 360 °) ÷ 360 °. For example, (359 ° + 360 °) ÷ 360 ° = 1, and this integer “1” is a number exceeding 360 °. The number exceeding 360 ° = 1 is used as the number exceeding 360 ° in step S52 of the next process.

  Further, in step S56, 360 ° is added to the angular movement amount fix, and this result is set as the angular movement amount fix. For example, the angular movement amount fix = 170 ° + 360 ° = 530 ° is set as the angular movement amount fix. In FIG. 8, 530 ° is indicated by point f.

  Thereafter, in step S39 shown in FIG. 6, the angle data obtained in step S1 is processed as the previous angle data, and in step S40, the angle movement amount fix = 530 ° is set to the previous angle movement amount = 530 °. I do. Then, in step S41, the rotational speed of the positive rotation of the rotor is obtained by calculation from the above equation (1) using the angular movement amount fix = 530 °.

On the other hand, in step S52, for example, when the number exceeding 360 ° is 0, if the angle moving amount fix = 190 °, the angle moving amount fix = (190 ° + 360 ° exceeding number × 360 °) = 190 °. Furthermore, in step S53, for example, it is assumed that the angle movement amount fix = 190 ° is subtracted from the previous angle movement amount = 359 °, and Δangle movement amount = 169 ° is obtained. In this case, since the determination in step S54 is No, it is further determined in step S57 whether or not the Δ-angle movement amount = 169 ° is smaller than −180 °. Since this determination result is No, the process proceeds to step S39.

  Thereafter, in step S39, the angle data obtained in step S1 is processed as the previous angle data, and in step S40, for example, the angle movement amount fix = 190 ° is processed as the previous angle movement amount. In step S41, the rotational speed of the positive rotation of the rotor is calculated from the above equation (1) using the angular movement amount fix = 190 °.

On the other hand, in step S52, for example, when the number exceeding 360 ° is 2, assuming that the amount of angular movement fix = −30 °, (−30 + (− 2) × 360 °) = − 750 °, and the amount of angular movement fix = −. 750 °. In FIG. 9, −750 ° is indicated by the s point. Furthermore, in step S53, for example, it is assumed that the angle movement amount fix = −750 ° is subtracted from the previous angle movement amount = −1070 ° to obtain Δangle movement amount = −320 °. In this case, since the determination in step S54 is No, it is further determined in step S57 whether or not the Δ-angle movement amount = −320 ° is smaller than −180 °. Since this determination result is Yes, the number exceeding 360 ° is obtained in step S58. For example, (previous angle movement amount = −1070 ° −360 °) ÷ 360 ° = −3 , and this integer “−3” is used as the number exceeding 360 ° in the next step S52 as the number exceeding 360 °.

  Further, in step S59, 360 ° is subtracted from the angular movement amount fix = −750 °, and the result is −1110 ° as the angular movement amount fix, and the process proceeds to step S39. In step S39, the angle data obtained in step S1 is processed as the previous angle data, and in step S40, for example, the angle movement amount fix = -1110 ° is processed as the previous angle movement amount. In step S41, the rotation speed of the negative rotation of the rotor is obtained by calculation from the above equation (1) using the angular movement amount fix = -1110 °.

  As described above, the rotational speed measurement device 10 of the present embodiment detects the rotational position of 0 ° to 360 ° of the rotating body that rotates forward or negatively in reverse, by an electrical angle, and uses an integer value corresponding to the electrical angle. A resolver 12 that outputs a certain angle detection value, an angle movement amount that is a movement amount of the angle detection value that is output from the resolver 12 within a predetermined time, and a rotation direction of the rotating body are obtained, and based on the angle movement amount. And a rotation speed calculation circuit 13 for obtaining the rotation speed of the rotating body.

  This feature is that when the difference between the previous angular movement amount and the current angular movement amount exceeds 180 °, the rotational speed calculation circuit 13 determines that the rotating body has exceeded 360 ° to the positive rotation side. In this determination, an angle of 360 ° is added to the current angular movement amount, and the addition result is used as the angular movement amount used for obtaining the rotational speed.

  As a result, even if the amount of angular movement of the rotating body detected by the resolver 12 within a predetermined time is an ultra-high speed rotation exceeding 360 ° on the positive rotation side, the rotational speed can be measured without reducing the angle detection accuracy. it can.

  Further, when the rotational speed calculation circuit 13 determines that the rotating body has exceeded the 360 ° angle on the positive rotation side, the rotational speed calculating circuit 13 holds the number of times exceeding the 360 ° angle, and sets the 360 ° angle to this number of times of holding. The multiplied value is added to the angle movement amount that is the movement amount of the angle detection value output from the resolver 12 within a predetermined time to obtain a new angle movement amount.

  As a result, the number of times that the rotating body exceeds the angle of 360 ° is held, and a value obtained by multiplying the number of times of holding by the angle of 360 ° is added to the next obtained angle movement amount to obtain a new angle movement amount. I made it. Therefore, even if the rotating body changes from high-speed rotation to higher-speed ultra-high-speed rotation, the amount of angular movement at this time can be obtained appropriately.

Further, the rotational speed calculation circuit 13 determines that the rotating body has exceeded the 360 ° angle on the negative rotation side when the difference between the previous angular movement amount and the current angular movement amount exceeds the angle of −180 °. At the time of this determination, an angle of −360 ° is added to the current angular movement amount , and this result is used as the angular movement amount used for obtaining the rotation speed.

  As a result, even when the amount of angular movement of the rotating body detected by the resolver 12 within a predetermined time exceeds 360 ° on the negative rotation side, the rotational speed can be measured without reducing the angle detection accuracy. .

  Further, when the rotational speed calculation circuit 13 determines that the rotating body has exceeded the 360 ° angle on the negative rotation side, the rotational speed calculation circuit 13 holds the number of times that the 360 ° angle has been exceeded on the negative rotation side. A value obtained by multiplying the angle of ° is added to the angle movement amount that is the movement amount of the angle detection value output from the resolver 12 within a predetermined time to obtain a new angle movement amount.

  As a result, the number of times that the rotating body has exceeded the 360 ° angle on the negative rotation side is held, and a value obtained by multiplying the number of holding times by the 360 ° angle is added to the amount of angular movement to be obtained next to obtain a new angle movement. I tried to make it an amount. Therefore, even if the rotating body changes from high-speed rotation to higher-speed ultra-high-speed rotation, the amount of angular movement at this time can be obtained appropriately.

DESCRIPTION OF SYMBOLS 10 Rotational speed measuring device 11 Motor 12 Resolver 13 Rotation number calculation circuit

Claims (4)

A rotation angle detection sensor for detecting a rotation position of 0 ° to 360 ° of a rotating body that rotates forwardly or in the negative direction by an electrical angle and outputs an angle detection value that is an integer value corresponding to the electrical angle; A rotational speed calculation means for obtaining an angular movement amount that is a movement amount of the angle detection value output from the rotational angle detection sensor within a predetermined time, and obtaining a rotational direction and a rotational speed of the rotating body based on the angular movement amount; In the rotational speed measuring device having,
When the difference between the previous angular movement amount and the current angular movement amount exceeds a 180 ° angle, the rotational speed calculation means determines that the rotating body has exceeded a 360 ° angle on the positive rotation side. At the time of determination, a rotational speed measuring device characterized in that an angle of 360 ° is added to the current angular movement amount, and the addition result is used as an angular movement amount used for obtaining the rotational speed.   When the rotational speed calculation means determines that the rotating body has exceeded the 360 ° angle on the positive rotation side, the rotational speed calculation means retains the number of times exceeding the 360 ° angle, and multiplies this number of times by the 360 ° angle. The obtained value is added to an angle movement amount that is a movement amount within a predetermined time of the angle detection value output from the rotation angle detection sensor next time to obtain a new angle movement amount. The described rotational speed measuring device. When the difference between the previous angular movement amount and the current angular movement amount exceeds −180 °, the rotational speed calculation means determines that the rotating body has exceeded the 360 ° angle on the negative rotation side, 2. The rotational speed measuring apparatus according to claim 1, wherein an angle of −360 ° is added from the current angular movement amount at the time of the determination, and the result is used as an angular movement amount used for obtaining the rotational speed. .   When the rotation number calculation means determines that the rotating body has exceeded the 360 ° angle on the negative rotation side, the rotation number means holds the number of times that the 360 ° angle has been exceeded on the negative rotation side, and 360 ° A value obtained by multiplying the angle is added to an angle movement amount that is a movement amount within a predetermined time of the angle detection value output from the rotation angle detection sensor, to obtain a new angle movement amount. The rotational speed measuring device according to claim 3.

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