TWI424163B - Estimation method for rotational speed and computer readable medium using the same - Google Patents

Description

Speed estimation method and computer readable medium using the same

The present invention relates to a method for estimating a rotational speed and a computer readable medium thereof, and more particularly to a method for estimating a rotational speed applied to motor rotational speed control and a computer readable medium thereof.

In the prior art, motor speed estimation methods have existed and are widely used in various applications. Generally, the motor has a photoelectric encoder for generating a phase-encoded signal A and a phase-encoded signal B having a phase difference of 90 degrees from each other. For example, each time the motor rotates, the generated phase-encoded signals A and B trigger M pulse signals correspondingly, and M is a natural number greater than 1. In the prior art, the frequency measurement method (or M method) and the measurement period method (or the T method) are two commonly used calculation methods for estimating the rotation speed of the motor according to the pulse signals. The resulting speed estimate can be used to control the speed of the motor.

However, how to design a speed estimation method with a wide range of speed estimation and accurate speed estimation results is one of the continuous efforts of the industry.

The invention relates to a method for estimating the rotation speed and a computer readable medium using the same, compared with the traditional speed estimation method, the speed estimation method and the computer readable medium of the invention have a wide range of speed estimation and speed estimation. The result is more precise.

According to a first aspect of the present invention, a method for estimating a rotational speed and a computer readable medium having the same are provided for estimating a rotational speed of a motor device. The speed estimation method includes the following steps. First, first and second sampling signals are provided. The first and second sampling signals respectively have first and second sampling frequencies, and the first sampling frequency is substantially greater than the second sampling frequency. Then, the first operation parameter is determined according to the maximum rotation speed information of the motor device and the first sampling signal, and the second operation parameter is determined according to the maximum rotation speed information and the second sampling signal. When the rotational speed information of the motor device corresponds to the first rotational speed condition, the first sampling signal and the first operational parameter are selected as sampling signals and operational parameters, respectively. When the speed information reaches the second speed condition, the second sampling signal and the second operation parameter are selected as sampling signals and operation parameters, respectively. The sampled phase encoded signal of the motor device is then sampled by a sample signal to obtain a sampled value. The speed estimate is then generated based on the sampled value and the operational parameters. The first and the second rotational speed conditions correspond to different rotational speed ranges, and the rotational speed range of the first rotational speed condition is higher than the rotational speed range of the second rotational speed condition.

According to a second aspect of the present invention, a method for estimating a rotational speed and a computer readable medium recording the same are provided for estimating a rotational speed of a motor device. The speed estimation method includes the following steps. Firstly, the first operation parameter is determined according to the maximum rotation speed information of the motor device and the first phase encoding signal, and the second operation parameter is determined according to the maximum rotation speed information of the motor device and the second phase encoding signal, and the first and second phase encoding signals are respectively Having different generation frequencies, the frequency of the first phase encoded signal is substantially less than the frequency of the second phase encoded signal. When the rotational speed information of the motor device reaches the first rotational speed condition, the first phase encoded signal and the first operational parameter are selected as the phase encoded signal to be sampled and the operational parameter respectively. When the speed information reaches the second speed condition, the second phase coded signal and the second operation parameter are selected as the phase coded signal and the operation parameter to be sampled, respectively. The sampled phase-encoded signal is then sampled with a sampled signal to obtain a sampled value. The speed estimate is then generated based on the sampled value and the operational parameters. The first and second rotational speed conditions correspond to different rotational speed ranges, and the rotational speed range of the first rotational speed condition is higher than the rotational speed range of the second rotational speed condition.

According to a third aspect of the present invention, a method for estimating a rotational speed and a computer readable medium recording the same are provided for estimating a rotational speed of a motor device. The speed estimation method includes steps a to c. First, as step a, the operation parameters are determined according to the maximum speed information of the motor device and the phase coded signal to be sampled. Then, in step b, the sampled phase-encoded signal is sampled by the sampled signal to obtain a sampled value, wherein step b further includes sub-steps b1 to b5. First, the first and second counters are provided as in step b1, and the first and second count values are respectively recorded. In the initial state, the first and second count values correspond to the end count value. Then, as step b2, when the phase coded signal to be sampled is received, the second counter is driven to make the second count value equal to the first count value, and the first counter is driven to reset the first count value as the start count value. Then, as in step b3, the first counter is driven to increment the first count value by one when the sampling signal is received. In step b4, the first counter is driven to terminate the operation of step b3 when the first count value is equal to the highest count value, so that the first count value is maintained at the highest count value. In step b5, the second count value is read as the sampled value. Then, as step c, the speed estimation value is generated based on the sampled value and the operation parameter.

In order to better understand the above and other aspects of the present invention, the preferred embodiments are described below, and in conjunction with the drawings, the detailed description is as follows:

Referring to FIG. 1, a block diagram of a motor system to which the rotational speed estimating method of the embodiment of the present invention is applied is shown. For example, the motor system 1 includes a speed control loop 110, a current control loop 112, a voltage vector converter 114, a current vector converter 116, an equivalent drive system 118, a signal feedback interface circuit 120, a speed calculation circuit 122, and a motor. Device 124. Motor unit 124 includes an optical encoder for generating a phase encoded signal. For example, the motor device 124 generates a phase-encoded signal A and a phase-encoded signal B by an optical encoder, wherein the phase-coded signals A and B have a phase difference of 90 degrees. When the motor unit 124 rotates once, the phase-encoded signals A and B respectively trigger N pulse period signals, where N is a natural number greater than one.

The speed calculation circuit 122 includes a processor and a computer readable medium. The computer readable medium is used to record a code corresponding to the speed estimation method of the embodiment of the present invention, and the processor is readable by the computer. The medium estimates the rotational speed of the motor unit 124 by performing the rotational speed estimation method of the embodiment of the present invention.

Further, although the speed estimation method performed by the speed calculation circuit 122 of the present invention is mainly modified for the conventional measurement period method (or the T method), it is possible to obtain accurate speed estimation values, but it can also integrate existing The frequency measuring method (or M method) is used to obtain the running direction information of the motor device 124 according to the frequency measuring method. Furthermore, in the operation of obtaining the direction information of the motor device 124, the speed calculation circuit 122 obtains the rotation direction information of the motor device 124 based on the phase relationship of the phase-encoded signals A and B in the motor device 124. .

In order to obtain the estimated value of the rotational speed of the motor device 124, the phase-coded signal A or B is sampled by the sampling signal to obtain a corresponding rotational speed estimate. Next, several embodiments will be described to further explain the related operations of the measurement period method performed by the speed calculation circuit 122.

First embodiment

The rotation speed estimating method of the embodiment selects one of the plurality of sampling signals according to the rotation speed information of the motor device, and samples the phase-encoding signal accordingly. Referring to FIG. 2, a flow chart of a method for estimating the rotational speed according to the first embodiment of the present invention is shown. First, as in step (a), the speed calculation circuit 122 provides the sampling signals Ss1 and Ss2, and accordingly samples the phase-encoded signal A or B generated by the optical encoder in the motor unit 124 to obtain the sampled value X. Based on the sampled value and the cycle time of the sampled signal, the speed calculation circuit 124 can obtain the time required for the motor unit 124 to rotate one revolution, that is, the estimated speed of the motor unit 124. The sampling signals Ss1 and Ss2 have first and second sampling frequencies, respectively, and the first sampling frequency is substantially greater than the second sampling frequency. For example, the speed calculation circuit 122 includes a Complex Programmable Logic Device (CPLD) for providing the sampling signals Ss1 and Ss2 and performing sampling timing operations.

Next, in step (b), the speed calculation circuit 122 determines the operation parameter P1 according to the maximum rotation speed information of the motor device 124 and the sampling signal Ss1, and determines the operation parameter P2 based on the maximum rotation speed information and the sampling signal Ss2. For example, the speed calculation circuit 122 calculates the operational parameters P1 and P2 according to the following equation:

Wherein Rs is the maximum rotational speed of the motor device 124; T1 and T2 are the cycle times of the sampling signals Ss1 and Ss2, respectively; N is the number of pulse wave cycles corresponding to the phase-encoded signal A or B for each rotation of the motor device 124; K is the number of speed resolution range bits to be obtained in the speed calculation circuit 122.

In one example of operation, the maximum speed of the motor unit 124 is 4.167 revolutions per second (Revolution per Second, rps); the sampling signals Ss1 and Ss2 correspond to frequencies of 10 megahertz (Megahertz, MHz) and 19.53 kHz (Kilohertz, respectively). KHz), in other words, it has a cycle time T1 of 100 nanoseconds (ns) and a cycle time T2 of 51.2 microseconds (microsecond, μs); for each rotation, the phase-encoded signal generated by the optical encoder corresponds to the trigger The number N of pulse wave periods is 2048; the number K of speed resolution ranges to be obtained in the speed calculation circuit 122 is, for example, 15 bits. Accordingly, the speed calculation circuit 122 can obtain the operation parameters P1 and P2 corresponding to the values of 3.84×10 ⁷ and 7.5×10 ⁴ , respectively, according to the foregoing equation.

After step (b), the speed calculation circuit 122 obtains the rotational speed information of the motor unit 124. For example, the rotational speed information is, for example, the rotational speed value of the motor device 124 obtained by the speed calculating unit 122 in the previous rotational speed estimating operation.

When the rotational speed information corresponds to the first rotational speed condition, the rotational speed estimating method of the present embodiment proceeds to step (c), and the speed calculating circuit 122 selects the sampling signal Ss1 as the sampling signal, and selects the operational parameter P1 as the operational parameter P. The first rotational speed condition corresponds to the first rotational speed range of the motor device 124. For example, this first speed range corresponds to 4.167 rps to 4.46 revolutions per minute (Revolution Per Minute, rpm). After step (c), steps (e) and (f) are performed, and the speed calculation circuit 122 sequentially samples the phase-coded signal of the motor device 124 according to the sample signal (ie, the sample signal Ss1) to obtain the sample value X. And generating a speed estimation value Y based on the sampled value X and the operation parameter P. For example, the speed calculation circuit 122 generates a speed estimation value Y based on the sampled value X and the operation parameter according to the following equation:

When the rotation speed information corresponds to the second rotation speed condition, the rotation speed estimation method of the embodiment proceeds to step (d), the speed calculation circuit 122 selects the sampling signal Ss2 as the sampling signal, and selects the operation parameter P2 as the operation parameter P. The second rotational speed condition corresponds to a second rotational speed range of the motor device 124, and the second rotational speed range is lower than the first rotational speed range. For example, this second rotational speed range corresponds to 4.46 rpm to 0.0087 rpm. After step (d), steps (e) and (f) are performed, and the speed calculation circuit 122 sequentially samples the phase-coded signal of the motor device 124 according to the sample signal (ie, the sample signal Ss2) to obtain the sample value X. And generating a speed estimation value Y based on the sampled value X and the operation parameter P. For example, the speed calculation circuit 122 generates a speed estimation value Y based on the sampled value X and the operation parameter according to the following equation:

As such, the speed calculation circuit 122 of the present embodiment can perform the sampling operation of the phase-encoded signal by the sampling signals Ss1 and Ss2 of different frequencies according to the rotational speed of the motor device 124 corresponding to different numerical ranges. Thus, the speed calculation circuit 122 of the present embodiment can effectively provide a wider range of speed estimation range when the length of the register and the frequency of the phase-encoded signal are fixed, compared to the speed calculation circuit applying the conventional speed estimation method. .

Referring to FIG. 3, a partial flow chart of the method for estimating the rotational speed of the first embodiment of the present invention is shown. For example, the step (e1) to (e5) are included in the step (e) of the rotational speed estimating method of the present embodiment. First, as in step (e1), the speed calculation circuit 122 has a first counter and a second counter of X bits, which respectively record the count values CV1 and CV2. For example, X is equal to 16. In the initial state, the count values CV1 and CV2 are equal to the end count value, which corresponds, for example, to one of the first and second counters, the highest count value (FFFF) ₁₆ , as shown in FIG.

Step (e1) further includes a step (e2). When the phase encode signal is received, the speed calculation circuit 122 drives the second counter to make the count value CV2 equal to the count value CV1, and drives the first counter to reset the count value. CV1 is the starting count value (0000) ₁₆ . In this embodiment, the receiving of the phase encoder signal receives its leading edge (for example, Rising Edge) ED1, but is not limited thereto.

Step (e1) further includes a step (e3). When receiving the sampling signal (that is, one of the sampling signals Ss1 and Ss2), the speed calculation circuit 122 drives the first counter to increment the count value CV1 by one. In this embodiment, the receiving of the phase encoder signal receives its leading edge (for example, Rising Edge) ED1, but is not limited thereto. However, the order relationship between the steps (e2) and (e3) and the number of operations differ depending on the operation state of the motor unit 124. For example, when the motor device 124 is operating normally, the step (e2) is performed after the step (e1), and the step (e3) is performed after the step (e2); and the step (e3) is performed at the plurality of steps (e3). After the operation, the speed estimation method of the embodiment performs step (e2) again, thereby recording the number of triggers of the sampled signals between the two phase-coded signals, and the number of triggers of the sampled signals, that is, how many sample signals are corresponding. The cycle time also represents the time required for the motor unit 124 in operation to rotate N minutes.

After the step (e3), when the count value CV1 is equal to the highest count value, the step (e4) is executed, and the speed calculation circuit 122 drives the operation of the first counter termination step (e3) to maintain the count value CV1 at the highest count value (FFFF). ) ₁₆ .

The speed calculation circuit 122 further performs the step (e5) to read the second count value CV2 as the sample value X.

In the present embodiment, the case where the step (e4) is performed after the step (e3) is taken as an example. However, the method of estimating the rotational speed of the present embodiment is not limited thereto. In other examples, the rotational speed of the motor unit 124 is higher, and the count value CV1 is reset by the trigger of step (e2) before incrementing to its highest count value. In other words, step (e2) may be repeated after step (e3) or step (e5) may be directly performed without performing the operation of step (e4).

In the present embodiment, the case where the step (e5) is performed after the step (e4) is taken as an example. However, the method of estimating the number of revolutions of the present embodiment is not limited thereto. In other examples, the step (e5) speed estimation method may also be performed after step (e3) or after (e4).

Through the control of the first and second counters by the speed calculation circuit 122, the speed calculation circuit 122 can further determine the change of the rotation speed of the motor device 124 according to the values of the reference count values CV1 and CV2. For example, when the count values CV1 and VC2 are equal to the value (FFFF) ₁₆ , it means that the initial rotational speed of the motor device 124 and the current rotational speed are both 0, in other words, the motor device 124 has not started to rotate; when the count value CV1 is equal to the value ( FFFF) ₁₆ and the count value CV2 is equal to a value other than the value (FFFF) ₁₆ , indicating that the motor unit 124 once had a rotational speed that is not equal to zero, and then its rotational speed approaches the value zero again.

In the present embodiment, the speed calculation circuit 122 selectively supplies the sampling signals Ss1 and Ss2 of different operating frequencies according to the determination condition that the rotational speed information of the motor device 124 corresponds to the first or second rotational speed condition. The case of the sampling operation of the phase-encoded signal is taken as an example. However, the speed calculation circuit 122 of the present embodiment is not limited thereto. For example, in steps (a) and (b), the speed calculation circuit 122 further provides a sampling signal Ss3 having a third sampling frequency (the second sampling frequency of the sampling signal Ss2 is substantially greater than the third sampling frequency) and The operation parameter P3 is determined according to the maximum rotation speed information of the motor device 124 and the sampling signal Ss3; and the rotation speed estimation method executed by the speed calculation circuit 122 of the embodiment can further perform the step (g) to set the rotation speed information of the motor device 124. Three or more speed conditions, and optionally provide three or more sampling signals with different operating frequencies for phase encoding signal sampling operations, as shown in Figure 5. In this way, the speed calculation circuit 122 of the present embodiment can realize a wider range of the speed estimation range by setting a larger number of rotation conditions.

In the embodiment, the speed calculation circuit 122 uses the sampling signals of a plurality of different operating frequencies to sample the single phase-encoded signal. For example, the speed calculation circuit 122 of the embodiment of the present invention is described. It is not limited to this, and a plurality of sampling signals of different operating frequencies can be simultaneously applied to sample the phase-encoded signals of a plurality of different operating frequencies.

For example, the motor device 124 of the embodiment is further configured to provide a phase encode signal PHC1, and the speed calculation circuit 122 generates a phase encode signal PHC2 corresponding to a different operating frequency according to the phase encode signal PHC1, wherein the operating frequency of the phase encode signal PHC1 It is substantially smaller than the operating frequency of the phase coded signal PHC2. In one example of operation, the phase-encoded signal PHC1 is one of the phase-encoded signal A and the phase-encoded signal B (the phase difference between the two phase-coded signals) generated by the motor device 124, and the phase-coded signal PHC2 is the speed calculation. The circuit 122 generates a four-frequency phase-encoded signal based on the phase-encoded signals A and B, and the zero-phase phases of the phase-encoded signals PHC1 and PHC2 are triggered at the same time.

Please refer to FIG. 6, which illustrates still another flowchart of the method for estimating the rotational speed according to the first embodiment of the present invention. Different from the flowchart shown in FIG. 2, in step (b'), the speed calculation circuit 122 determines the operation parameter P1 according to the maximum rotation speed information of the motor device 124, the sampling signal Ss1, and the phase encode signal PHC1, and according to this, The maximum speed information, the sampled signal Ss2, and the phase coded signal PHC2 determine the operational parameter P2. For example, the speed calculation circuit 122 calculates the operational parameters P1 and P2 according to the following equation:

Wherein Rs is the maximum speed of the motor device 124; T1 and T2 are the cycle times of the sampling signals Ss1 and Ss2, respectively; N1 and N2 are the pulse signals corresponding to the phase-encoded signals PHC1 and PHC2 for each rotation of the motor device 124. The number of cycles, for example, N2 is equal to, for example, 4N1; K is the number of speed resolution range bits to be obtained in the speed calculation circuit 122.

When the rotational speed information corresponds to the first rotational speed condition, the rotational speed estimating method proceeds to step (c'), and the speed calculating circuit 122 selects the sampling signal Ss1 as the sampling signal, selects the phase encoded signal PHC1 as the phase-coded signal to be sampled, and selects The operation parameter P1 is taken as the operation parameter P. When the rotational speed information corresponds to the second rotational speed condition, the rotational speed estimating method proceeds to step (d'), and the speed calculating circuit 122 selects the sampling signal Ss2 as the sampling signal, selects the phase encoded signal PHC2 as the phase-coded signal to be sampled, and The operation parameter P2 is selected as the operation parameter P.

In this way, a plurality of different speed estimation ranges can be correspondingly processed through a plurality of arrangement combinations of a plurality of different operating frequency sampling signals and a plurality of phase encoding signals of different operating frequencies. Accordingly, the speed calculation circuit 122 of the present embodiment can achieve a wider range of speed estimation.

For example, the method for estimating the speed of the embodiment may be configured in a computer readable medium, so that the corresponding processor can read and load the foregoing code to implement the foregoing speed estimation of the present invention. method.

Second embodiment

The method for estimating the rotational speed of the present embodiment selects one of the plurality of phase-encoded signals according to the rotational speed information of the motor device, and samples one of the plurality of phase-encoded signals according to the single sampled signal, and accordingly, the embodiment The method for estimating the rotational speed can also achieve a relatively wide range of rotational speed estimation through the selection operation of the plurality of phase-encoded signals.

For example, the motor device 124 of the embodiment is further configured to provide a phase encode signal PHC1, and the speed calculation circuit 122 generates a phase encode signal PHC2 corresponding to a different operating frequency according to the phase encode signal PHC1, wherein the operating frequency of the phase encode signal PHC1 It is substantially smaller than the operating frequency of the phase coded signal PHC2.

In one example of operation, the phase-encoded signal PHC1 is one of the phase-encoded signal A and the phase-encoded signal B (the phase difference between the two phase-coded signals) generated by the motor device 124, and the phase-coded signal PHC2 is the speed calculation. The circuit 122 generates a four-frequency phase-encoded signal based on the phase-encoded signals A and B, and the zero-phase phases of the phase-encoded signals PHC1 and PHC2 are triggered at the same time.

Referring to FIG. 7, a flow chart of a method for estimating a rotational speed according to a second embodiment of the present invention is shown. First, in step (b), the speed calculation circuit 122 determines the operation parameter P1' based on the highest speed information of the motor unit 124 and the phase encode signal PHC1, and determines the operation parameter P2' based on the highest speed information and the phase coded signal PHC2. For example, in step (b), the speed calculation circuit 122 calculates the operational parameters P1' and P2' according to the following equation:

Wherein Rs is the maximum speed of the motor device 124; T1 is the cycle time of the sampling signal Ss1; N1 and N2 are the number of pulse cycles of the phase-encoded signals PHC1 and PHC2 for each rotation of the motor device 124; K is the speed calculation circuit The number of scratchpad bits used to record this sampled value in 122. The maximum speed of the motor device 124 is 4.167 rps; the sampling signal Ss1 corresponds to a cycle time T1 of 100 ns; for each revolution, the number of pulse cycles N1 and N2 corresponding to the phase-encoded signals PCH1 and PCH2 are 2048 and 2048×4, respectively. That is, the phase coded signal PCH2 is the quadruple frequency signal of the phase coded signal PCH1; in the example where the value K is equal to 15, the operation parameters P1' and P2' correspond to the values of 3.84×10 ⁷ and 0.96×10 ^{7 , respectively} .

When the speed information corresponds to the first speed condition, the speed estimation method of the embodiment proceeds to step (c), and the speed calculation circuit 122 selects the phase coded signal PHC1 as the phase coded signal to be sampled, and performs the operation parameter P1'. For the operation parameters. The first rotational speed condition corresponds to the first rotational speed range of the motor device 124. After step (c), steps (e) and (f) are performed, and the speed calculation circuit 122 sequentially samples the phase coded signal PHC1 of the motor device 124 according to the sample signal to obtain a sample value X, and according to the sample value X. And the operation parameter P generates a speed estimation value Y. The operations in steps (e) and (f) are substantially the same as steps (e) and (f) in FIG. 2, respectively, and are not described herein again.

When the speed information corresponds to the second speed condition, the speed estimation method of the embodiment proceeds to step (d), and the speed calculation circuit 122 selects the phase coded signal PHC2 as the phase coded signal to be sampled, and performs the operation parameter P2'. For the operation parameters. The second rotational speed condition corresponds to the second rotational speed range of the motor device 124. After step (d), steps (e) and (f) are performed, and the speed calculation circuit 122 sequentially samples the phase coded signal PHC2 of the motor device 124 according to the sample signal to obtain a sample value X, and according to the sample value X. And the operation parameter P generates a speed estimation value Y. The operations in steps (e) and (f) are substantially the same as steps (e) and (f) in FIG. 2, respectively, and are not described herein again.

As such, the speed calculation circuit 122 of the present embodiment can use the phase-encoding signals PHC1 and PHC2 of different frequencies as the phase-encoding signals to be sampled according to the rotational speeds of the motor devices 124 corresponding to different numerical ranges. Thus, the speed calculation circuit 122 of the present embodiment can effectively provide a wider range of speed estimation range when the length of the register and the frequency of the phase-encoded signal are fixed, compared to the speed calculation circuit applying the conventional speed estimation method. .

Please refer to FIG. 8 , which is a flow chart showing a method for estimating the rotational speed according to the second embodiment of the present invention. Similar to the speed estimation method shown in FIG. 5, the speed calculation circuit 122 can also generate two or more frequency doubling phase coded signals according to the phase coded signal PHC1, which is executed by the speed calculation circuit 122 of the present embodiment. The speed estimation method may further perform step (g) to set three or more speed conditions for the speed information of the motor unit 124, and selectively apply the three or more phase codes having different operating frequencies. The signal is used as the phase coded signal to be sampled. In this way, the speed calculation circuit 122 of the present embodiment can realize a wider range of the speed estimation range by setting a larger number of rotation conditions.

Similar to the description in the first embodiment relating to the third embodiment, the step (e) in the rotational speed estimating method of the present embodiment may also include sub-steps (e1)-(e5).

Through the control of the first and second counters by the speed calculation circuit 122, the speed calculation circuit 122 can further determine the change of the rotation speed of the motor device 124 according to the values of the reference count values CV1 and CV2. For example, when the count values CV1 and VC2 are equal to the value (FFFF) ₁₆ , it means that the initial rotational speed of the motor device 124 and the current rotational speed are both 0, in other words, the motor device 124 has not started to rotate; when the digital value CV1 is equal to the value ( FFFF) _{16 and the} digit value CV2 is equal to a value other than the value (FFFF) ₁₆ , indicating that the motor unit 124 once had a rotational speed that is not equal to zero, and then its rotational speed approaches the value zero.

In this embodiment, the speed calculation circuit 122 uses only a sampling signal of a single operating frequency to perform sampling operation on one of the plurality of phase-encoded signals. However, the speed calculation circuit of the embodiment of the present invention is described. 122 is not limited to this, and a plurality of sampling signals of different operating frequencies may be simultaneously applied to perform sampling operations on a plurality of phase-coded signals of different operating frequencies, as in the flow shown in FIG. 6 in the first embodiment. step.

For example, the foregoing method for estimating the rotational speed of the present invention can be built in a computer readable medium, so that the corresponding processor can read and load the aforementioned code to implement the foregoing method for estimating the rotational speed of the present invention. .

Third embodiment

The speed estimation method of this embodiment applies two counters to perform a speed estimation operation on the motor unit. Referring to FIG. 9, a flow chart of a method for estimating a rotational speed according to a third embodiment of the present invention is shown. First, as in step (a), the speed calculation circuit 122 determines the operation parameter P based on the maximum rotational speed information of the motor device 124 and the sampling signal Ss.

Then, in step (b), the speed calculation circuit 122 sequentially samples the phase-encoded signal of the motor device 124 according to the sample signal Ss to obtain the sample value X. Thereafter, as in step (c), the speed calculation circuit 122 generates a rotational speed estimate based on the sampled value X and the operational parameter P.

For example, step (b) further includes steps (b1)-(b5). First, as step (b1), a first counter having z bits and a second counter are provided, and the count value CV1 and the count value CV2 are respectively recorded. For example, z is equal to 16. In the initial state, the count values CV1 and CV2 are equal to the end count value, which corresponds, for example, to one of the first and second counters, the highest count value (FFFF) ₁₆ , as shown in FIG.

Step (b1) further includes step (b2). When the phase encode signal is received, the speed calculation circuit 122 drives the second counter to make the count value CV2 equal to the count value CV1, and drives the first counter to reset the count value. CV1 is the starting count value (0000) ₁₆ . In this embodiment, the receiving end of the phase encoder signal receives its leading edge, for example, the rising edge ED1, but is not limited thereto.

Step (b1) further includes step (b3). When receiving the sampling signal, the speed calculation circuit 122 drives the first counter to increment the count value CV1 by one. In this embodiment, the receiving end of the phase encoder signal receives its leading edge, for example, the rising edge ED1, but is not limited thereto. However, the order relationship between the steps (b2) and (b3) and the number of operations differ depending on the operation state of the motor unit 124. For example, when the motor unit 124 is operating normally, the step (b2) is performed after the step (b1), and the step (b3) is performed after the step (b2); and the step (b3) is performed in the plurality of steps (b3). After the operation, the speed estimation method of the embodiment performs step (b2) again, thereby recording the number of triggers of the sampled signals between the two phase-coded signals, and the number of triggers of the sampled signals, that is, how many sample signals are corresponding. The cycle time also represents the time required for the motor unit 124 in operation to rotate N minutes.

After the step (b3), when the count value CV1 is equal to the highest count value, the step (b4) is executed, and the speed calculation circuit 122 drives the operation of the first counter termination step (b3) to maintain the count value CV1 at the highest count value (FFFF). ) ₁₆ .

The speed calculation circuit 122 further performs the step (b5) to read the count value CV2 as the sample value X.

In the present embodiment, the case where the step (b4) is performed after the step (b3) is taken as an example. However, the method of estimating the rotational speed of the present embodiment is not limited thereto. In other examples, the rotational speed of the motor unit 124 is higher, and the count value CV1 is reset by the trigger of step (b2) before incrementing to the highest count value thereof. In other words, step (b2) may be repeated after step (b3) or step (b5) may be directly performed without performing the operation of step (b4).

In the present embodiment, the case where the step (b5) is performed after the step (b4) is taken as an example. However, the method of estimating the rotational speed of the present embodiment is not limited thereto. In other examples, the step (b5) speed estimation method may also be performed after step (b3) or after (b4).

In this embodiment, steps (d), (e), (f), (g) are further included before step (a), and respectively, and steps (a), (b), (in Figure 2), respectively. c), (d) have substantially corresponding operations, and will not be described again (not shown). In this embodiment, steps (d'), (e'), (f') may also be included before step (a), which respectively correspond to steps (b), (c), (d) in FIG. It has a substantially corresponding operation, and will not be described again here (not shown).

The method for estimating the rotational speed of this embodiment selects one or more sampling signals of different operating frequencies to perform sampling operations on one or more phase-coded signals of different operating frequencies. Accordingly, the rotational speed estimating method of the present embodiment has an advantage that the rotational speed estimating range is wider than the conventional rotational speed estimating method.

In addition, the method for estimating the rotational speed of the present embodiment integrates the frequency measuring method and the measuring period method more effectively, so as to effectively obtain the rotation direction information of the motor device and the estimated speed value thereof, according to which, compared with the conventional speed estimation method, The method for estimating the rotational speed of the embodiment has the advantages of integrating the frequency measuring method and the measuring period method to obtain more accurate information on the rotational operation of the motor device.

Furthermore, since the rotational speed estimating method of the present embodiment applies the measuring period method to calculate the rotational speed estimated value of the motor device. Referring to the equation of the embodiment of the present invention, it is known that the calculation formula of the rotational speed estimation value of the present embodiment does not include a factor related to the operating frequency of the speed calculation circuit. Accordingly, the Ripple value of the rotational speed estimate is not increased by increasing the operating frequency of the speed calculation circuit (to increase the operating speed of the high speed calculation circuit). Accordingly, the rotational speed estimating method of the present embodiment has an advantage of providing a lower chopping value and a more accurate motor device rotational speed estimation value at the same operating speed than the conventional rotational speed estimating method. Further, the motor device referred to in the present invention includes a common motor device such as an inner rotor motor, an outer rotor motor, a wind power generator, and a motor for a vehicle.

In addition, although the present invention mainly uses the measurement cycle method to calculate the motor speed, those skilled in the art can easily combine it with the frequency method, and use the frequency method to reinforce the periodic method, which cannot determine the directionality. Although the invention can greatly improve the speed measurement range and accuracy of the periodic method, since the periodic method is mainly used for medium and low speed measurement, the present invention can also switch to the frequency method at high speed by combining with the frequency method. To make the application scope of the invention more extensive and practical.

In conclusion, the present invention has been disclosed in the above preferred embodiments, and is not intended to limit the present invention. A person skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

1. . . Motor system

110. . . Speed control loop

112. . . Current control loop

114. . . Voltage vector converter

116. . . Current vector converter

118. . . Equivalent drive system 118

120. . . Signal feedback interface circuit

122. . . Speed calculation circuit

124. . . Motor unit

Fig. 1 is a block diagram showing a motor system to which a rotational speed estimating method according to an embodiment of the present invention is applied.

2 is a flow chart showing a method of estimating the rotational speed according to the first embodiment of the present invention.

FIG. 3 is a partial flow chart showing the method for estimating the rotational speed of the first embodiment of the present invention.

FIG. 4 is a schematic diagram showing numerical changes of the count values CV1 and CV2.

Fig. 5 is a flow chart showing another method of estimating the rotational speed according to the first embodiment of the present invention.

Fig. 6 is a flow chart showing still another method of estimating the rotational speed according to the first embodiment of the present invention.

FIG. 7 is a flow chart showing a method for estimating the rotational speed according to the second embodiment of the present invention.

Figure 8 is a flow chart showing another method of estimating the rotational speed in accordance with the second embodiment of the present invention.

Figure 9 is a flow chart showing a method of estimating the rotational speed in accordance with a third embodiment of the present invention.

(a)-(f). . . Steps

Claims (14)

A method for estimating a rotational speed for estimating a rotational speed of a motor device, the method for estimating the rotational speed comprising: (a) providing a first sampling signal and a second sampling signal, wherein the first and second sampling signals respectively have a first a sampling frequency and a second sampling frequency, the first sampling frequency is substantially greater than the second sampling frequency; (b) determining a first operational parameter according to the highest rotational speed information of the motor device and the first sampling signal, And determining a second operation parameter according to the maximum speed information and the second sampling signal; (c) selecting a first sampling signal as a sampling signal when the speed information of the motor device reaches a first speed condition And selecting the first operation parameter as an operation parameter; (d) when the rotation speed information of the motor device reaches a second rotation speed condition, selecting the second sampling signal as the sampling signal, and selecting the second operation The parameter is used as the operation parameter; (e) sampling the phase-coded signal to be sampled by the motor device with the sample signal to obtain a sample value; and (f) The sampling value and the operation parameter generate an estimated speed value; wherein the first and the second speed conditions respectively correspond to different speed ranges, and the speed range of the first speed condition is higher than the speed range of the second speed condition . The method for estimating the rotational speed according to the first aspect of the patent application, wherein the steps (c) and (d) further comprise: (c1) selecting a first phase-encoding signal of the motor device as the phase-coded signal to be sampled. And (d1) selecting a second phase-encoding signal of the motor device as the phase-coded signal to be sampled; wherein the first and second phase-coded signals have different generating frequencies, and the first phase-encoding signal The frequency is substantially less than the frequency of the second phase encoded signal. The method for estimating the rotational speed according to the first aspect of the patent application, wherein the step (e) further comprises: (e1) providing a first counter and a second counter, respectively generating a first count value and a second count value. The first and the second count value correspond to a termination count value; (e2) when receiving the phase-coded signal to be sampled, driving the second counter to make the second count value equal to the first count value, And driving the first counter to reset the first count value to a start count value; (e3) when receiving the sample signal, driving the first counter to increment the first count value by 1; (e4) When the first count value is equal to a highest count value, the first counter is driven to terminate the operation of the step (e3) to maintain the first count value at the highest count value; and (e5) the second count value is read. For this sample value. For example, the method for estimating the rotational speed described in claim 1 wherein steps (a) and (b) further comprise: (a1) providing a third sampling signal, the third sampling signal having a third sampling frequency, the second sampling frequency being substantially greater than the third sampling frequency; and (b1) according to the maximum rotational speed information and the third sampling The signal determines a third operational parameter; wherein the rotational speed estimating method further comprises between step (b) and (e): (g) selecting the third sampling when the rotational speed information corresponds to a third rotational speed condition The signal is used as the sampling signal, and the third operation parameter is selected as the operation parameter, wherein the third rotational speed condition corresponds to another rotational speed range, and the rotational speed range of the second rotational speed condition is higher than the third rotational speed condition. range of rotation. A computer readable medium for recording a method for estimating the rotational speed of one of the first to fourth aspects of the patent application. A method for estimating a rotational speed for estimating a rotational speed of a motor device, the method for estimating the rotational speed comprising: (a) determining a first operational parameter according to a maximum rotational speed information of the motor device and a first phase encoded signal, and The maximum speed information and a second phase encoding signal determine a second operating parameter, the first and second phase encoded signals have different generating frequencies, and the frequency of the first phase encoded signal is substantially smaller than the second phase The frequency of the encoded signal; (b) when the rotational speed information of the motor device corresponds to a first rotational speed condition, the first phase encoded signal is selected as a phase-coded signal to be sampled, and the first operational parameter is selected as An arithmetic parameter; (c) when the rotational speed information corresponds to a second rotational speed condition, selecting the second phase encoded signal as the phase encoded signal to be sampled, and selecting the second operational parameter as the operational parameter; (d) The sampling signal samples the phase-coded signal to be sampled to obtain a sample value; and (e) generates an estimated speed value according to the sampled value and the operation parameter; wherein the first and second speed conditions correspond to different speed ranges The speed range of the first speed condition is higher than the speed range of the second speed condition. The method for estimating the rotational speed of claim 6, wherein the method further comprises: (f) providing a first sampling signal and a second sampling signal, wherein the first sampling signal and the second sampling signal respectively have a first sampling frequency And a second sampling frequency, wherein the first sampling frequency is substantially greater than the second sampling frequency; wherein, in step (d), the method further comprises: when the operation parameter is the first operation parameter, selecting the first sampling signal to do For the sampling signal; and when the operation parameter is the second operation parameter, the second sampling signal is selected as the sampling signal. The method for estimating the rotational speed according to the sixth aspect of the patent application, wherein the step (d) further comprises: (d1) providing a first counter and a second counter, respectively recording a first count value and a second count value; The first and second count value pairs Receiving a count value; (d2) receiving the phase coded signal to be sampled, driving the second counter, causing the second count value to be equal to the first count value, and driving the first counter to reset the first count The value is a starting count value; (d3) receiving the sampling signal, driving the first counter, incrementing the first count value by 1; (d4) driving the first when the first count value is equal to a highest count value The counter terminates the operation of step (d3) to maintain the first count value at the highest count value; and (d5) reads the second count value as the sample value. The method for estimating a rotational speed according to the sixth aspect of the invention, wherein the step (a) further comprises: providing a third phase encoded signal having a different generating frequency from the first and second phase encoded signals, The frequency of the second phase-encoded signal is substantially smaller than the frequency of the third phase-encoded signal, and a third operational parameter is determined according to the maximum rotational speed information and the third phase-encoded signal; wherein the rotational speed estimation method is in the step (a) And (d) further comprising: (g) when the rotational speed information corresponds to a third rotational speed condition, selecting the third phase encoded signal as the phase-coded signal to be sampled, and selecting the third operational parameter to do For the operation parameter, the third rotational speed condition corresponds to another rotational speed range, and the rotational speed range of the second rotational speed condition is higher than the rotational speed range of the third rotational speed condition. A computer readable medium for recording the scope of patent application Method for estimating the speed of one of the 6 to 9 items. A method for estimating a rotational speed for estimating a rotational speed of a motor device, the method for estimating the rotational speed comprising: (a) determining an operational parameter according to a maximum rotational speed information of the motor device and a phase-coded signal to be sampled; (b) A sampling signal samples the phase-coded signal to be sampled to obtain a sample value, wherein the step (b) further comprises: (b1) providing a first counter and a second counter, respectively recording a first count value and a second count value, the first and second count values corresponding to a termination count value; (b2) when receiving the phase coded signal to be sampled, driving the second counter such that the second count value is equal to the a first count value, and driving the first counter, resetting the first count value to a start count value; (b3) when receiving the sample signal, driving the first counter, incrementing the first count value by one; (b4) when the first count value is equal to a highest count value, driving the first counter to terminate the operation of step (b3), maintaining the first count value at the highest count value; and (b5) reading the first Two count values as the take And (c) generating an estimated speed value based on the sampled value and the operational parameter. The method for estimating the rotational speed as described in claim 11 wherein before step (a), the method further comprises: (d) providing a first sampling signal and a second sampling signal, the first sampling signal and the second sampling signal respectively having a first sampling frequency and a second sampling frequency, the first sampling frequency being substantially greater than the second a sampling frequency; (e) determining a first operational parameter according to the maximum rotational speed information of the motor device and the first sampling signal, and determining a second operational parameter according to the maximum rotational speed information and the second sampling signal; f) when the rotational speed information of the motor device corresponds to a first rotational speed condition, selecting the first sampling signal as the sampling signal, and selecting the first operational parameter as the operational parameter; and (g) when the When the rotational speed information corresponds to a second rotational speed condition, the second sampling signal is selected as the sampling signal, and the second operational parameter is selected as the operational parameter; wherein the first and the second rotational speed conditions are different The speed range, the speed range of the first speed condition is higher than the speed range of the second speed condition. The method for estimating the rotational speed according to claim 11, wherein before the step (a), the method further comprises: (d') determining a first according to the highest rotational speed information of the motor device and a first phase encoded signal. Calculating a parameter, and determining a second operation parameter according to the maximum rotation speed information of the motor device and a second phase encoding signal, wherein the first and second phase encoding signals have different generating frequencies, and the first phase encoding signal The frequency is substantially smaller than the frequency of the second phase-encoded signal; (e') when the rotational speed information of the motor device corresponds to a first rotational speed In the condition, the first phase coded signal is selected as the phase coded signal to be sampled, and the first operation parameter is selected as the operation parameter; (f') when the speed information corresponds to a second speed condition, The second phase-encoded signal is used as the phase-coded signal to be sampled, and the second operational parameter is selected as the operational parameter; wherein the first and second rotational speed conditions respectively correspond to different rotational speed ranges, the first The speed range of the speed condition is higher than the speed range of the second speed condition. A computer readable medium for recording a method of estimating the rotational speed of one of the 11th to 13th patent applications.