CN100538574C - Signal processing apparatus, method, pick-up unit and servo control mechanism - Google Patents

Abstract

Carry out signal Processing to detect the actuating speed of motor for the location information signal of exporting from sensor corresponding to the activation point of motor (Asin θ, Acos θ).Possess: the location information signal carries out the location information signal handling part (410) of signal Processing with the actuating speed information of calculating motor; The up-to-date actuating speed information (ω that reflection is calculated by location information signal handling part (410) _n) be used as the interior location information generating unit (460) of interior location information with the up-to-date estimated position that generates motor.Location information signal handling part (410) basis is from the location information signal (Asin θ, Acos θ) of sensor and interior location information (the Asin θ that is generated by interior location information generating unit (460) _n, Acos θ _n) difference come the actuating speed information (ω of calculating motor _n).

Description

Signal processing device, method, detection device and servo mechanism

technical field

The present invention relates to a signal processing device, for example, to a signal processing device, a signal processing method, a signal processing program, A recording medium, a speed detection device, and a servo mechanism that controls the driving speed of the motor.

Background technique

Conventionally, there is known a servo mechanism that controls the driving speed (for example, rotational speed) of a motor (for example, Document 1: JP-A-2004-5218).

Existing servomechanism 1 is equipped with as shown in Figure 12: as the electric motor 11 of control object; The control unit 13 controls the current applied to the motor 11 so that the motor rotation speed becomes a target speed while simultaneously controlling the rotation speed of the motor.

The encoder 12 performs latching while detecting the rotational position (rotation angle) of the motor 11, and outputs information on the rotational position of the motor 11 in absolute code. Furthermore, the encoder 12 and the control unit 13 are connected via a serial communication line 14 .

FIG. 13 shows a timing chart of the rotation speed control of the motor 11 in the servo mechanism having the above-mentioned configuration.

First, a command S ₁ for position detection is transmitted from the control unit 13 to the encoder 12 via the serial communication line 14 . When receiving the detection instruction _S1 , the encoder 12 detects the rotational position of the motor 11 (shown as P ₀ , P ₁ , P ₂ in FIG. 13 ), and at the same time, latches the detection value and outputs the position data of the motor 11. to the control section 13.

When receiving the rotational position data of the motor 11 from the encoder 12, the control unit 13 controls the speed of the motor 11 according to the rotational position of the motor. That is, the control unit 13 compares the received motor rotational position with the motor rotational position received one cycle before to calculate the rotational speed of the motor 11 , and compares the calculated motor rotational speed with the target speed. Then, the duty ratio of the current applied to the motor 11 is calculated from the difference between the motor speed and the target speed, and the speed of the motor 11 is controlled in accordance with the calculated duty ratio.

By repeating the above-mentioned control cycle, the rotation speed of the motor 11 is controlled to be the target speed.

However, as described above, when the speed control is performed based on the motor speed calculated from the difference between the motor rotational position data detected at a certain sampling cycle and the speed data obtained by the calculation becomes the current control cycle. Velocity and the average velocity data of the velocity of the previous cycle. In this way, in speed control, a dead time (time delay) of 1/2 of the sampling period T occurs. Due to such dead time, the phase delay of the control system increases, resulting in a problem that control stability is impaired.

Contents of the invention

The main object of the present invention is to provide a signal processing device, a signal processing method, a signal processing program, a speed detection device, and a method for controlling the driving speed of a motor to be stable according to a signal from an encoder to quickly obtain the driving speed of the controlled object. servo mechanism.

The signal processing device of the present invention is a signal processing device that performs signal processing on a position information signal output from a sensor corresponding to the driving position of the driving body and detects the driving speed of the driving body, and is characterized in that it includes: position information signal processing an internal position information generating unit that reflects the latest driving speed information calculated by the position information signal processing unit to generate The latest estimated position of the driving body is used as internal position information, wherein the position information signal processing unit uses the position information signal from the sensor and the internal position generated by the internal position information generating unit information to calculate the driving speed information of the driving body.

In this structure, the position information of the driving body reflecting the latest driving speed information of the driving body is generated as the internal position information in the internal position information generation part, and once the position information signal of the driving body is input from the sensor, the position information signal is immediately displayed on the position information signal. The processing unit calculates the difference between the position information signal of the sensor and the internal position information. Based on this difference, the driving speed of the driving body is calculated and output. The driving speed is output to an external control unit as driving speed information of the driving body, for example, and is input to the internal position information generating unit for estimating the latest position of the driving body.

Here, since the internal position information generation unit usually generates the position information of the driving body reflecting the latest driving speed information, it holds the latest position information of the driving body estimated as much as possible. Therefore, the time gap (Δt) between the internal position information generated by the internal position information generation unit and the position information signal input from the sensor can be reduced. The difference between the position information signal and the internal position information generated by the internal position information generating unit becomes the differential value of the position information signal from the sensor, and becomes the driving speed of the driving body without change.

Since the estimated position of the driver is generated in advance as the internal position information by the internal position information generator, once the position information signal is input from the sensor, the difference between the two is immediately calculated to obtain the driving speed of the driver. Furthermore, the obtained driving speed information is substantially equal to the driving speed information obtained by immediately differentiating the position information signal input from the sensor, and it is possible to obtain speed information without delay with respect to the input position information.

In the past, the difference between the position of the current cycle and the control cycle before one cycle is calculated by using the position data obtained with a certain sampling cycle, so it is only the average speed obtained by 1/2 cycle delay. However, in the present invention, Since the driving speed at the moment when the input sampling signal (position information signal) can be obtained, the time delay is extremely small, and a special effect of improving the existing time delay across generations can be exhibited.

Therefore, for example, if the driving speed information obtained by the information processing device is used as a feedback signal to drive and control the driving body, since there is no phase delay, the control system can be extremely stable.

In the present invention, preferably, the internal position information generation unit generates the internal position information based on an integrated value obtained by sequentially integrating the driving speed information output from the position information signal processing unit.

According to such a configuration, since the output from the position information signal processing unit is the driving speed of the driving body at all times, the driving speed based on the speed information can be obtained by sequentially integrating the driving speed in the internal position information generating unit. body location information. Furthermore, internal position information for estimating the position of the driving body is obtained by integrating the latest driving speed information and estimating the driving amount of the driving body from the last input position information signal to the next time.

In this way, since the estimated position of the driver is generated in advance as the internal position information by the internal position information generator, once the position information signal is input from the sensor, the difference between the two can be immediately calculated to obtain the driving speed of the driver.

In the present invention, it is preferable that the positional information signal processing unit includes: a difference calculation means for calculating the difference between the positional information signal from the sensor and the internal positional information generated by the internal positional information generation unit; A speed calculating unit calculates driving speed information of the driving body based on the difference from the difference calculating unit.

Here, as the driving speed calculating means, the driving speed information is calculated by multiplying the difference calculated by the difference calculating means by a predetermined gain as an example.

With this configuration, the difference between the position information signal and the internal position information calculated by the difference calculation means is multiplied by, for example, an appropriate gain to calculate drive speed information corresponding to the characteristics of the driving body.

For example, when a sinusoidal signal that changes periodically corresponding to the driving position of the driving body is input from the sensor, the position information signal is a trigonometric function value with the phase as a parameter, and when it is desired to obtain the phase change amount as the driving speed information, use The driving speed calculation means converts the trigonometric function value into the phase change amount, and obtains the phase change amount as driving speed information.

In the present invention, preferably, the position information signal output from the sensor is a periodic function signal that changes periodically in response to the driving of the driving body, and the position information signal processing unit outputs a phase change of the periodic function signal. As the driving speed information of the driving body, the internal position information generation part includes: an integrating part that integrates the phase change amount from the position information signal processing part and calculates the position information of the driving body. a corresponding phase; and an internal position information conversion unit that calculates, as the internal position information, a periodic function value corresponding to the phase calculated by the integrating means.

In the above configuration, the amount of phase change is calculated as the drive speed information with respect to the position information signal of the periodic function input from the sensor. Then, the phase is calculated by integrating the drive speed information which is the amount of change in the phase, and furthermore, a periodic function value corresponding to the phase is calculated as internal position information.

Since the input is a periodic function value, in order to obtain the difference between the input position information signal and the internal position information, even if it is necessary to have a function value as internal position information, the internal position is used according to the phase calculated by the integrating part. The information conversion section calculates a function value corresponding to the phase. As a result, the difference between the input position information signal and the internal position information is immediately calculated, and velocity information without delay with respect to the input position information is obtained.

In addition, by having an internal position information conversion unit that calculates a predetermined function value using the phase as a parameter, even if the position information signal input from the sensor is not the phase information itself, it can be a sinusoidal signal or the like. The encoder (photoelectric, magnetic, capacitive, etc.) used as a sensor is used as a sensor as it is, and does not require special design changes that are only suitable for the signal processing device of the present invention. Therefore, it is simple and can avoid Costs rise.

In the present invention, preferably, the periodic function signal is a two-phase signal composed of a first signal and a second signal having a predetermined phase difference with each other, and the position information signal processing unit includes: a first signal processing unit, performing signal processing on the first signal and outputting a phase change amount of the first signal as the driving speed information; and a second signal processing unit performing signal processing on the second signal and outputting the second signal The amount of phase change is used as the driving speed information, and a signal switching unit is provided on the rear stage side of the position information signal processing unit, and the signal switching unit switches and selects the output signal from the first signal processing unit and the output signal from the first signal processing unit. 2 An output signal based on the periodic function signal whose signal value change amount is larger with respect to the phase change amount, among the output signals of the signal processing unit.

With this structure, since the phase change amount (driving speed information) calculated from the signal of the two-phase signal with a larger change in the signal value of the phase change amount is selected by the signal switching unit, it is possible to obtain the driving speed as the driving speed with high precision. The amount of phase change of the information.

If the position information signal output from the sensor is a periodic function, there is an area where the rate of change of the function value with respect to the phase change becomes small, so even if the internal position information is subtracted from the periodic function value, it may not be possible to achieve high accuracy. However, if two-phase signals with a phase difference are switched and a signal (the first signal or the second signal) with a large change amount relative to the phase change signal is used, it can be obtained with high precision over the entire range. The amount of phase change.

Here, for example, the periodic function signal is a trigonometric function signal with a phase difference of 90 degrees, the first signal may be a sine wave signal (Asinθ), the second signal may be a cosine wave signal (Acosθ), or the first signal may be is tanθ, and the second signal is 1/tanθ.

Further, even when the biphase signal output from the sensor is a sine wave signal (Asinθ) and a cosine wave signal (Acosθ), it is also possible to use Asinθ) signal processing of the two-phase signal to detect the driving speed of the driving body. Thus, if the ratio of the two signals is obtained, an input signal that is not affected by fluctuations in signal amplitude can be obtained.

In the present invention, preferably, the periodic function signal is a sinusoidal signal, and the signal switching unit includes a judging unit that compares the signal value of any one of the first signal and the second signal with a predetermined value. Threshold values are compared and size judgment is performed; and switching means, based on the judgment result produced by the judgment part, performs switching between the output signal from the first signal processing part and the output signal from the second signal processing part switch.

For example, if the absolute value of one signal value is smaller than the threshold value, that signal value may be used, and if the absolute value of one signal value is higher than the threshold value, the other signal value may be used.

According to such a configuration, when the absolute value of the sinusoidal signal is large, the rate of change with respect to the phase becomes small, and a signal with a large rate of change with respect to the phase is selected based on the magnitude of the predetermined threshold value. Thus, the amount of phase change can be obtained with high precision over the entire range. In addition, it is simple to determine which one has a larger amount of signal change with respect to the phase change than complicated arithmetic processing, and only needs to compare one signal value with a threshold value to determine the magnitude.

In the present invention, it is preferable to include a sign conversion unit that converts the sign of the phase change amount output from the position information signal processing unit into a sign indicating an increase or decrease corresponding to the moving direction of the driving body. symbol.

When the position information signal from the sensor is a periodic function that increases and decreases periodically, even when the driver is displaced in the positive direction and the phase increases, a region where the signal value of the position information signal decreases occurs. If the internal position information is simply subtracted from the above-mentioned reduced signal value, the amount of phase change will also become a negative value regardless of whether the driving body is displaced in the positive direction or the phase increases. In this regard, in the present invention, since the sign conversion unit is provided, even if the phase change amount is calculated as a negative value when the driving body is displaced in the positive direction, the sign of the phase change amount can be converted into a value corresponding to In the increase/decrease direction of the moving direction of the driving body, the correct drive speed (phase change amount) in the increase/decrease direction is obtained, and the internal position information is generated based on the correct drive speed (phase change amount) in the increase/decrease direction.

Moreover, generally, in an encoder as a sensor, a periodically changing sinusoidal signal is output as the output of the sensor. In the signal processing device of the present invention, since a sign conversion unit is provided, it is possible to pass the signal output from a general sensor. The drive speed of the controlled object can be obtained after the sensor signal is properly processed, and no special design change is required only for the signal processing device of the present invention, so it is simple and can avoid cost increase.

In the present invention, it is preferable that the internal position information generating unit includes: a first integrating unit that integrates the phase change amount of the first signal output from the first signal processing unit to calculate the The phase corresponding to the position information of the driving body; the first internal position information conversion part calculates the function value of the first signal based on the phase calculated by the first integration part; integrating the phase change amount of the second signal output by the signal processing unit to calculate a phase corresponding to the position information of the driving body; phase, calculating the function value of the second signal.

In the above configuration, the sensor outputs the first signal and the second signal as two-phase signals, the first signal is processed by the first signal processing unit to output the phase change amount of the first signal, and the second signal is processed and output by the second signal processing unit The amount of phase change of the second signal. The phase change amount of the first signal output from the first signal processing unit is sequentially integrated by the first integrating means to calculate the latest phase of the first signal. The phase calculated by the first integrating unit is input to the first internal position information conversion unit, and the first internal position information conversion unit calculates the function value of the first signal as the latest estimated position of the driving body. In the first signal processing unit, the difference between the function value of the first signal calculated by the first internal position information conversion unit and the first signal input from the sensor is calculated, and the driving speed of the driving body is calculated based on the difference.

The phase change amount of the second signal output from the second signal processing unit is sequentially integrated by the second integrating means to calculate the latest phase of the second signal. The phase calculated by the second integrating means is input to the second internal position information conversion unit, and the second internal position information conversion unit calculates the function value of the second signal as the latest estimated position of the driving body. The second signal processing unit calculates the difference between the function value of the second signal calculated by the second internal position information conversion unit and the second signal input from the sensor, and calculates the driving speed of the driver based on the difference.

And, the signal selected by the signal switching unit among the output signal from the first signal processing unit and the output signal from the second signal processing unit is output as the driving speed of the driving body.

According to the above-mentioned structure, when the biphase signal of the first signal and the second signal is output from the sensor, the first integrating unit and the first internal position information converting unit are provided corresponding to the first signal processing unit that processes the first signal, and The second signal processing unit that processes the second signal includes a second integrating unit and a second internal position information converting unit correspondingly. Thus, when calculating the driving speed of the driving body based on the first signal, in the loop composed of the first integrating part and the first internal position information conversion part using the phase change amount based on the first signal as feedback information, it is possible to use The driving speed information is calculated based only on the arithmetic processing of the first signal.

Again, similarly, when calculating the driving speed of the driving body based on the second signal, in the loop formed by the second integral part and the second internal position information conversion part using the phase change amount based on the second signal as feedback information, The driving speed information can be calculated by arithmetic processing based only on the second signal.

Therefore, for example, even if the amplitudes of the first signal and the second signal are different, each speed information output from each position information processing unit (first signal processing unit, second signal processing unit) will not be influenced by the first signal. and the influence of the amplitude difference of the second signal. Thus, the influence of the amplitude difference between the first signal and the second signal is suppressed, and even when the driving speed information output from the first signal processing part and the second signal processing part is switched by the signal switching part, the output driving Velocity information is also smoothly continuous.

In the present invention, preferably, the driving body is a motor having a rotor, the position information signal output from the sensor is a periodic function signal that changes periodically corresponding to the rotational driving of the motor, and the position information signal The signal processing unit outputs the rotation angular velocity as the driving speed information of the motor, the integrating unit integrates the rotation angular velocity from the position information signal processing unit, and calculates the rotation phase angle of the motor, and the internal position information conversion unit calculates based on A periodic function value of the motor's rotational phase angle.

According to this configuration, the rotational angular velocity can be obtained as the driving speed of the motor from the periodic function signal output from the sensor corresponding to the rotational drive of the motor.

The signal processing method of the present invention is a signal processing method for performing signal processing on a position information signal output from a sensor corresponding to the driving position of the driving body to detect the driving speed of the driving body, and is characterized in that it includes: a position information signal processing step , performing signal processing on the position information signal to calculate the driving speed information of the driving body; and an internal position information generating step reflecting the latest driving speed information calculated by the position information signal processing step to generate the The latest estimated position of the driving body is used as internal position information, wherein the position information signal processing step is based on the position information signal from the sensor and the internal position information generated by the internal position information generating step. to calculate the driving speed information of the driving body.

With the above-mentioned structure, the same effect as that of the above-mentioned invention can be exhibited.

The signal processing program of the present invention is a signal processing program executed by a computer incorporated in a signal processing device that performs signal processing on a position information signal output from a sensor corresponding to the driving position of the driving body and detects the The driving speed of the driving body is characterized in that the computer functions as a position information signal processing unit and an internal position information generating unit, and the position information signal processing unit performs signal processing on the position information signal and calculates the the driving speed information of the driving body, the internal position information generation unit reflects the latest driving speed information calculated by the position information signal processing unit and generates the latest estimated position of the driving body as the internal position information, At the same time, the position information signal processing unit calculates driving speed information of the driving body based on a difference between the position information signal from the sensor and the internal position information generated by the internal position information generating unit.

The recording medium of the present invention is characterized in that the above-mentioned signal processing program is recorded.

In this way, by loading the signal processing program into the computer and making the computer function as each functional unit, it is possible to easily change various parameters and the like.

Also, when loading the signal processing program, a memory card or CD-ROM may be directly inserted into the signal processing device, or these storage media may be connected to the signal processing device through an external reading device. Furthermore, the signal processing program may be supplied and loaded by connecting to the signal processing device with a LAN cable, a telephone line, etc. through communication, or supplied and loaded wirelessly.

A speed detection device according to the present invention is characterized by comprising: a sensor that outputs a position information signal corresponding to the driving position of the driving body; and the above-mentioned signal processing device.

With this configuration, it is possible to create a speed detection device that processes the position information signal from the sensor by the signal processing device to quickly obtain the driving speed of the driving body.

The servomechanism of the present invention is characterized in that it comprises: a driving body; a sensor that outputs a position information signal corresponding to the driving position of the driving body; the signal processing device; and a central control unit configured by the signal processing device The detected driving speed of the driving body is compared with an external predetermined target speed and simultaneously the driving speed of the driving body is controlled to the predetermined target speed.

With the above configuration, the driving speed information obtained by the signal processing device is used as a feedback signal, and the driving control of the driving body is performed by the central control unit. In this way, since there is no phase delay, the control system can be made extremely stable.

The signal processing device of the present invention performs signal processing on the position information signal output from the sensor corresponding to the driving position of the driving body and detects the driving speed of the driving body, and is characterized in that it includes: a position information signal processing unit for the performing signal processing on the position information signal to calculate driving speed information of the driving body; and an internal position information generating unit reflecting the latest driving speed information calculated by the position information signal processing unit to generate the driving speed information of the driving body. The latest estimated position is used as internal position information, the position information signal output from the sensor is a periodic function signal that changes periodically in response to the driving of the driving body, and the position information signal processing unit calculates the phase of the periodic function signal The amount of change is used as the driving speed information of the driving body, and the internal position information generation unit includes an integrating unit for integrating the phase change amount from the position information signal processing unit to calculate the position of the driving body. a phase corresponding to the information; and an internal position information conversion unit that calculates a periodic function value corresponding to the phase calculated by the integrating unit as the internal position information, the position information signal processing unit according to the information from the The driving speed information of the driving body is calculated based on the difference between the position information signal of the sensor and the internal position information generated by the internal position information generating unit.

Description of drawings

FIG. 1 is a block diagram showing a first embodiment of a servo mechanism according to the present invention.

FIG. 2 is a diagram showing an example of a biphase signal output from an encoder in the first embodiment.

FIG. 3 is a block diagram showing the configuration of a speed calculation unit in the first embodiment.

4 is a diagram showing a relationship between a sine wave signal (Asinθ) input from an encoder and internal position information (Asinθn) generated by an internal position information generating unit in the first embodiment.

FIG. 5 is a diagram showing a configuration of a speed calculation unit of a signal processing device according to a second embodiment of the present invention.

6 is a diagram showing an example of a tangent signal (tanθ) and a cotangent signal (1/tanθ) generated from a ratio of biphase signals from an encoder in the second embodiment.

FIG. 7 is a block diagram showing the configuration of a speed calculation unit in the third embodiment.

8 is a diagram showing an example of the motor rotation speed ω output when the amplitude of the sine wave signal and the cosine wave signal differ by 5% in the configuration of the first embodiment.

9 is a diagram showing an example of the motor rotational angular velocity ω output when the amplitude of the sine wave signal and the cosine wave signal differ by 5% in the configuration of the third embodiment.

FIG. 10 is a diagram showing a configuration of a fourth embodiment.

FIG. 11 is a diagram showing a modified example of the present invention.

FIG. 12 is a diagram showing the structure of a conventional servo mechanism.

FIG. 13 is a time chart showing the rotation speed control of the motor in the conventional servo mechanism.

Detailed ways

Hereinafter, the embodiments of the present invention will be described with reference to symbols assigned to respective parts in the drawings.

(first embodiment)

A first embodiment of the servo mechanism of the present invention will be described.

A block diagram of a servo mechanism is shown in FIG. 1 .

This servomechanism 100 includes: a motor (drive body) 110 as a control object; and a code as a sensor that outputs a position information signal (periodic function signal) of a sine wave (Asinθ) and a cosine wave (Acosθ) corresponding to the rotational drive of the motor 110. and a controller 300 that calculates the motor rotation speed (drive speed information) based on the position information signal from the encoder 120 and simultaneously controls the motor rotation speed based on a target speed input from the outside.

The encoder 120 is a conventionally known rotary encoder 120 whose details are omitted, has a rotating body that rotates integrally with the rotor of the motor 110, and outputs position information signals (Asinθ, Acosθ), wherein the above-mentioned position information signals (Asinθ, Acosθ) is a periodic function that changes periodically with the rotation of the rotor. As shown in FIG. 2 , the position information signal is a two-phase signal of a sine wave (Asinθ) and a cosine wave (Acosθ) having a phase difference of 90 degrees. As such a rotary encoder 120 , a photoelectric encoder, a capacitive encoder, a magnetic encoder, or the like can be used.

The control unit 300 includes: a speed calculation unit 400 as a signal processing device that processes the position information signal from the encoder 120 and calculates the motor rotation speed; The CPU 310 of the central control section controls the motor rotation speed to the target speed by comparing with the target speed.

The configuration of the speed calculation unit 400 will be described.

FIG. 3 is a block diagram showing the configuration of the velocity calculation unit 400 .

The speed calculation unit 400 includes: a position information signal processing unit 410 that performs signal processing on the two-phase signals (Asinθ, Acosθ) output from the encoder 120 to calculate the motor rotation speed (ω _n ); The signal switching part 450 of the motor rotation speed information of any one signal in the phase signal; Generate the motor driving position information (θ _{n ) reflecting the latest motor rotation speed based on the motor rotation speed (ω n )} from the position information signal processing part 410 ) an internal position information generator 460 as internal position information; and an output unit 470 that outputs rotational speed information (ω _n ) of the motor 110 and motor drive position information (θ _n ).

The position information signal processing unit 410 includes a sinusoidal signal processing unit ( _first signal processing unit) 420; a cosine signal processing unit (second signal processing unit) that performs signal processing on the cosine wave signal (Acosθ) of the two-phase signal output from the encoder 120 and calculates the amount of rotation change (Δθ ₂ ) of the motor 110 430; Make the rotational angular velocity (ω ₁ , ω ₂ (rad/s)) of the motor 110 from the rotation variation (Δθ ₁ , Δθ ₂ ) from the sine signal processing unit 420 and the cosine signal processing unit 430 in conjunction with the positive rotation direction conversion unit 440 .

The sinusoidal signal processing unit 420 includes a first subtraction means (difference calculation means) that subtracts the internal position information (Asinθ _n ) generated by the internal position information generation unit 460 from the sinusoidal wave signal (Asinθ) input from the encoder 120 and outputs a difference signal. means) 421; a first gain multiplication unit (drive speed calculation means) 422 that calculates the motor rotation variation (Δθ ₁ ) after multiplying the differential signal output by the first subtraction means 421 by a predetermined gain (K).

The first subtraction unit 421 subtracts the motor drive position information (internal position information Asinθ _n ) generated by the internal position information generation unit 460 from the sine wave signal (Asinθ n ) input from the encoder 120 .

And, when the difference calculated by the first subtraction unit 421 becomes the difference (Asinθ−Asinθ _n ) of the function value, in the first gain multiplication unit 422, the differential signal output by the first subtraction unit 421 is multiplied by a predetermined gain (K ) after which the rotation change amount (Δθ ₁ ) of the motor 110 is output.

The cosine signal processing unit ₄₃₀ is provided with a second subtraction means (difference calculating means) 431; second gain multiplying means (driving speed calculating means) 432 which calculates the amount of motor rotation change ( _Δθ2 ) after multiplying the differential signal output by the second subtracting means 431 by a predetermined gain (K).

The sign conversion unit 440 includes: a first sign conversion unit 441 for converting the motor rotation variation (Δθ ₁ ) output from the sine signal processing unit 420 according to the sign of the cosine wave signal (Acosθ); The second sign conversion unit 442 converts the motor rotation variation (Δθ ₂ ) output from the cosine signal processing unit 430 .

The first sign conversion unit 441 multiplies the motor rotation variation (Δθ ₁ ) from the first gain multiplication unit 422 by -1 (minus 1) when the cosine wave signal (Acosθ) is negative (negative value), When the cosine wave signal (Acosθ) is positive (positive value), +1 (positive 1) is multiplied by the motor rotation change amount (Δθ ₁ ) from the first gain multiplication unit 422 .

Similarly, when the sine wave signal (Asinθ) is negative (negative value), the second sign conversion unit 442 multiplies the motor rotation variation (Δθ ₂ ) from the second gain multiplication unit by -1 (minus 1 ), when the sine wave signal (Asinθ) is positive (positive value), the motor rotation variation (Δθ ₂ ) from the second gain multiplication unit is multiplied by +1 (positive 1).

When the sine wave signal (Asinθ) input from the encoder 120 repeatedly increases and decreases periodically with the rotation of the motor 110 as shown in FIG. Therefore, if the internal position information (Asinθ _n ) generated by the internal position information generation unit 460 is simply subtracted from the input sine wave signal (Asinθ), the motor 110 may When the phase is increased, the amount of change in the rotation of the motor 110 also becomes a negative value. Therefore, in the first sign conversion unit 441, the sign of the output signal from the first gain multiplication unit 422 is converted into the sign of the motor 110 based on the sign of the cosine wave signal (Acosθ) which is another phase signal input from the encoder 120. The direction in which the amount of rotation change (Δθ ₁ ) increases. In this way, the motor rotation change amount (Δθ ₁ ) output from the first gain multiplier 422 is usually converted in an increasing direction, and the rotation angular velocity (ω ₁ ) of the motor 110 can be obtained.

Similarly, in the second sign conversion unit 442, the sign of the output signal from the second gain multiplication unit 432 is converted into the sign of the motor 110 according to the sign of the sine wave signal (Asinθ) which is another phase signal input from the encoder 120. The direction in which the amount of rotation change (Δθ ₂ ) increases. In this way, the motor rotation change amount (Δθ ₂ ) output from the second gain multiplier 432 is usually converted in an increasing direction, and the rotation angular velocity (ω ₂ ) of the motor 110 can be obtained.

The signal switching section 450 is equipped with: a judging section 451, which compares the sine wave signal (Asinθ) input from the encoder 120 with a predetermined threshold value to judge the magnitude of the sine wave signal and the threshold value; For size determination, the output signal from the sine signal processing unit 420 and the output signal from the cosine signal processing unit 430 are used to switch the input to the output unit and the internal position information generation unit 460 .

When the position information signal (Asinθ, Acosθ) input from the encoder 120 increases and decreases periodically with the rotation of the motor 110, for example, as shown in FIG. 2) and 270°(3π/2), there is a small change in the signal value relative to the change in the phase (θ), etc., whether it is a sine wave signal (Asinθ) or a cosine wave signal (Acosθ) relative to the phase The area where the signal value of the delta varies less.

Therefore, the signal switching unit 450 switches between the sine wave signal (Asinθ) and the cosine wave signal (Acosθ) in order to utilize a region in which the signal value varies greatly with respect to the amount of phase change.

The judging unit 451 compares the absolute value |Asinθ| of the sine wave signal with a predetermined threshold value of 0.7A, and judges the magnitude of both. Here, ±0.7 is approximately equivalent to ±√2/2. Taking a sine wave signal as an example, it is equivalent to 45°(π/4), 135°(3π/4), 225°(5π/4), 315°(9π /4) phase.

The switching part 452 has a sine-side terminal 453 for inputting a signal from the sine-signal processing part 420 and a cosine-side terminal 454 for inputting a signal from the cosine-signal processing part 430, and is constituted by a switching part. The switching part uses the sine-side terminal 453 and the cosine-side The terminal 454 switches the input to the internal position information generating unit 460 and the output unit 470 .

Furthermore, the signal switching unit 450 selects the sinusoidal side terminal 453 when |Asinθ| In case of A), select the cosine terminal 454.

As a result, as shown in FIG. 2 , among the sine wave signal (Asinθ) and the cosine wave signal (Acosθ), the region in which the signal value changes greatly is switched sequentially.

The internal position information generation unit 460 includes: an integration unit 461 for integrating the motor rotation angles (ω ₁ , ω ₂ ) from the position information signal processing unit 410 and calculating the rotation phase (θ _n ) of the motor 110; 461 The internal position information conversion unit 462 calculates the internal position information (Asinθ _n , Acosθ _n ) of the trigonometric function value of the calculated rotational phase (θ _n ) of the motor 110 as a parameter.

The integrating section 461 integrates the motor rotational angular velocity (ω ₁ or ω ₂ ), which is the output signal selected by the switching section 452 , and calculates the rotational phase (θ _n ) of the motor 110 . That is, the motor rotation phase (θ _n ) reflecting the latest motor rotation angular velocity (ω ₁ , ω ₂ ) is calculated. Then, the calculated motor rotation phase (θ _n ) is output to the internal position information conversion unit 462 .

The internal position information conversion unit 462 includes: a first internal position information conversion unit 463 that outputs internal position information (Asinθ _n ) to the first subtraction unit 421 of the sine signal processing unit 420; and a second subtraction unit to the cosine signal processing unit 430 431 outputs the second internal position information conversion unit 464 of the internal position information (Acosθ _n ).

The first internal position information conversion unit 463 calculates a sinusoidal function value (Asinθ _n ) in which the phase (θ _n ) calculated by the integrating unit 461 is a parameter corresponding to the sine wave signal (Asinθ) which is the position information signal input from the encoder 120 And as internal location information.

_{In addition} , the second internal position information conversion unit 464 calculates the cosine function value ( Acosθ _n ) and used as internal position information.

Here, when the integrating unit 461 integrates the motor rotation angular velocity (ω ₁ , ω ₂ ) output from the position information signal processing unit 410 and calculates the rotation phase (θ n ) of the motor 110 , the integration unit 461 calculates the rotation phase (θ _n ) of the motor 110 , and calculates the output of the position information signal processing unit 410 . The latest motor rotational angular velocities (ω ₁ , ω ₂ ) are sequentially integrated to calculate the latest motor rotational phase (θ _n ), which can be estimated as much as possible.

Furthermore, since the trigonometric function values (Asinθ _n , Acosθ _n ) of the latest motor rotational phase (θ _n ) calculated by the integrating unit 461 are calculated, the first and second internal position information converting units 463 and 464 hold The latest trigonometric function values (Asinθ _n , Acosθ _n ) of the motor rotation phase (θ _n ) estimated as possible are shown.

4 is a diagram showing a relationship between a sine wave signal (Asinθ) input from an encoder and internal position information (Asinθ _n ) generated by an internal position information generating unit.

The output unit 470 outputs the motor rotation angular velocity, which is the output signal selected by the switching unit 452 , to the CPU 310 as a central control unit through the filter 471 . In addition, examples of such a filter 471 include a low-pass filter and the like.

Furthermore, the output unit 470 outputs the motor rotation phase (θ _n ) calculated by the integrating unit 461 as motor drive position information.

The CPU 310 as the central control section compares the motor rotation angular velocity from the speed calculation section 400 with the target velocity input from the outside, and in order to make the motor rotation angular velocity (ω) the target velocity, the CPU 310 as the central control section calculates and applies to the motor The motor 110 is PWM controlled while controlling the duty cycle of the current (i) on the 110 .

The operation of the servo mechanism having the above configuration will be described.

When the motor 110 is rotationally driven, the rotation of the motor 110 is detected by the encoder 120 , and a two-phase signal (Asinθ, Acosθ) periodically changing with the rotation of the motor 110 is output from the encoder 120 .

Biphase signals (Asinθ, Acosθ) from the encoder 120 are input to the sine signal processing unit 420 and the cosine signal processing unit 430 , respectively. Since the subsequent processing of the sine wave signal (Asinθ) is substantially the same as the processing of the cosine wave signal (Acosθ), the following operations will be described using the processing of the sine wave signal (Asinθ) as an example.

In the first subtraction unit 421, the sine wave signal (Asinθ) input to the sine signal processing unit 420 is compared with the internal position information (Asinθ _n ) generated by the first internal position information conversion unit 463, and the difference between the two is calculated from The first subtraction unit 421 outputs to the first gain multiplication unit 422 .

In the first gain multiplication unit 422, a predetermined gain (K) is multiplied by the difference signal from the first subtraction means 421, and an amount of change in motor rotation (Δθ ₁ ) is output.

Then, depending on the sign of the cosine wave signal (Acosθ), which is the other signal of the two-phase signal, the motor rotation variation (Δθ ₁ ) from the first gain multiplication unit 422 is multiplied by +1 or -1, converted to the direction in which the amount of motor rotation change (Δθ ₁ ) increases, to generate the motor rotation angular velocity (ω ₁ ).

Similarly, the motor rotation angular velocity (ω ₂ ) based on the cosine wave signal (Acosθ) input to the cosine signal processing unit 430 is generated.

Furthermore, when generating the motor rotational angular velocity (ω ₁ ) from the sine signal processing unit 420 and the motor rotational angular velocity (ω ₂ ) from the cosine signal processing unit 430, based on the sine wave (Asinθ) in the judging unit 451 and the predetermined threshold value 0.7A The magnitude of is judged by the switching unit 452 to select the motor rotation angular velocity (ω ₁ or ω ₂ ) based on the area where the signal value changes greatly among the sine wave signal and the cosine wave signal.

Furthermore, the motor rotation angular velocity (ω _n ) from the switching unit 452 is divided into two, and one of them is input to the integration unit 461, and the integration performed by the integration unit 461 is used to calculate the motor rotation phase (θ _n ), reflecting the latest motor rotation speed. The rotational angular velocity (ω _n ) updates the rotational phase (θ _n ) of the motor 110 . The motor rotation phase (θ _n ) calculated by the integrating unit 461 is output to the first and second internal position information conversion parts 463 and 464 of the sine signal processing part 420 and the cosine signal processing part 430, and the internal position information conversion part 462 is used to A sine function value (Asinθ _n ) or a cosine function value (Acosθ _n ) with the motor rotational phase (θ _n ) as a parameter is generated.

Further, the branched motor rotational angular velocity (ω _n ) is output from the output unit 470 to the CPU 310 through the filter 471 .

The CPU 310 compares the motor rotation angular velocity (ω _n ) from the speed calculation unit 400 with the target speed, and calculates the duty ratio of the current (i) applied to the motor 110 so that the motor rotation angular velocity (ω) becomes the target value. . Then, the motor 110 is PWM-controlled based on the duty ratio, and the motor 110 is rotationally controlled at a predetermined target speed.

According to the first embodiment having the above configuration, the following effects can be exhibited.

(1) Since the internal position information generator 460 usually generates the position information (Asinθ _n , Acosθ _n ) of the motor 110 reflecting the latest motor speed information (ω _n ), it holds the latest position information of the motor 110 estimated as much as possible. location information. Therefore, the difference between the position information signal (Asinθ, Acosθ) from the encoder 120 and the internal position information (Asinθ _n , Acosθ _{n ) generated by the internal position information generator 460 becomes the position information signal (Asinθ, Acosθ n} ) from the encoder 120. ) becomes the driving speed (ω) of the motor 110 as it is. In this way, when the position information signal (Asinθ, Acosθ) is input from the encoder 120, the difference between the two is immediately calculated to obtain the driving speed (ω) of the motor, which can improve the existing time delay across generations. special effects.

(2) Since the motor drive speed (ω _n ) without time delay is obtained by the speed calculation unit 400, the central control unit (CPU) 310 performs a process for the motor 110 by using the motor drive speed information (ω _n ) as a feedback signal. Drive control, and thus, an extremely stable control system without phase delay can be created.

(3) Since there are first and second internal position information conversion units 463 and 464 for calculating the function value with the phase as a parameter, the position information signal input from the encoder 120 may be a sinusoidal signal or the like even if it is not the phase information itself. Therefore, the encoder (photoelectric, magnetic, capacitive, etc.) 120 that is generally used as a sensor can be directly used as a sensor without any change, and no special design change that is only suitable for the servo mechanism 100 of this embodiment is required. , therefore, it is not only simple but also avoids rising costs.

(4) Since the signal switching unit 450 selects the phase change amount (drive speed information) calculated from the signal of the two-phase signal (Asinθ, Acosθ) from the encoder 120 with a larger change in the value of the phase change amount signal, Therefore, the phase change amount (ω) as the motor speed information can be acquired with high accuracy over the entire range. In addition, when judging the signal with a larger signal change amount with respect to the phase change, no complicated arithmetic processing is required, and only one signal value (sine wave signal) is compared with a threshold value (0.7A) to judge the magnitude. Can, therefore, be handy.

(5) Since the sign conversion unit 440 is provided, even if the phase change amount is calculated as a negative value even when the motor 110 changes in the positive direction, the sign of the phase change amount (Δθ) is converted into In the increasing and decreasing direction of the rotation direction, the correct driving speed (phase change amount ω) in the increasing and decreasing direction can be obtained.

(second embodiment)

Next, a second embodiment of the servo mechanism of the present invention will be described with reference to FIG. 5 .

The basic configuration of the second embodiment is the same as that of the first embodiment, but the second embodiment has a feature that the ratio of the two-phase signals output from the encoder 120 is used as an input signal.

FIG. 5 is a diagram showing the configuration of a speed calculation unit (signal processing unit) according to the second embodiment.

In FIG. 5 , the speed calculation unit 500 includes a sensor signal conversion unit 600 that generates a dual phase signal based on the ratio of the sine wave signal (Asinθ) and the cosine wave signal (Acosθ) from the encoder 120 . phase signal (refer to Figure 6).

The sensor signal conversion unit 600 includes: a first signal conversion unit 610 that calculates Asinθ/Acosθ and outputs a tangent signal (tanθ) as a first signal; calculates Acosθ/Asinθ and outputs a cotangent signal (1/tanθ) as a second signal The second signal conversion unit 620.

The position information signal processing unit 510 includes: a first signal processing unit 520 that performs signal processing on the first signal (tanθ) to calculate the motor rotational angular velocity; and a second signal that performs signal processing on the second signal (1/tanθ) to calculate the motor rotational angular velocity. 2 Signal processing unit 530.

Furthermore, in the first signal processing unit 520, the internal position information generated by the internal position information generating unit 550 is subtracted from the first signal (tanθ) by the first subtraction unit 521 to output a differential signal, and the first gain multiplication unit is used to 522 multiplies the differential signal by a predetermined gain and outputs the motor rotation angular velocity (ω ₁ ).

In addition, in the second signal processing unit 530, the second signal (1/tanθ) is subtracted from the internal position information generated by the internal position information generating unit 550 by the second subtraction unit 531 to output a differential signal, and the second gain The multiplying section 532 multiplies the differential signal by a predetermined gain and outputs the motor rotational angular velocity (ω ₂ ).

In the signal switching part 540, the judging part 541 compares the magnitude of the first signal (tanθ) and 1, and the signal switching part 540 judges the magnitude based on the judging part 541, and when the first signal (tanθ) is equal to or less than 1, selects the The motor rotation angular velocity (ω ₁ ) of the 1 signal, and the motor rotation angular velocity (ω ₂ ) based on the second signal is selected when the first signal (tanθ) is greater than 1.

That is, as shown in FIG. 6, when the first signal (tanθ) and the second signal (1/tanθ) have discontinuous regions, the first signal (tanθ) and the second signal (1/tanθ) are alternately switched. continuous area.

In the internal position information generation part 550, the motor rotation angular velocity (ω ₁ , ω ₂ ) from the position information signal processing part 510 is integrated in the integration part 551 to calculate the motor rotation phase (θ _n ), and the internal position information conversion part In step 552, the motor rotation phase (θ _n ) is transformed into a trigonometric function value using the motor rotation phase (θ _n ) as a parameter.

Here, the first internal position information conversion unit 553 calculates a tangent function value (tanθ _n ) using the motor rotational phase (θ _n ) as a parameter, and outputs the value to the first subtraction unit 521 .

Also, the second internal position information conversion unit 554 calculates a cotangent function value (1/tanθ _n ) with the motor rotation phase (θ _n ) as a parameter, and outputs it to the second subtraction unit 531 .

Also, in the first embodiment, the sign conversion unit 440 is provided, and the output signals from the first gain multiplication units 422, 432 are converted in the increasing direction according to the rotation direction of the motor. However, in the second embodiment, since only the motor 110 changes in the direction of forward rotation, the utilization part (tanθ≤1) of the first signal (tanθ) increases monotonously, and the utilization part (tanθ>1) of the second signal (1/tanθ) decreases monotonically. Therefore, if For example, by subtracting the second signal (1/tanθ) from the internal position information in the second subtraction means 531 and determining the subtraction direction in advance, the motor rotation angular velocity generally indicating an appropriate increase or decrease direction can be obtained. Therefore, in the second embodiment, a sign converting unit is unnecessary.

According to the second embodiment having the above configuration, the same operational effects as those of the first embodiment can be exhibited.

Furthermore, since the sensor signal converting unit 600 generates the biphase signal (tanθ, 1/tanθ) based on the ratio of the biphase signal from the encoder 120, that is, the sine wave signal (Asinθ) to the cosine wave signal (Acosθ), therefore, It is possible to remove fluctuations in the amplitude A of the biphase signal (Asinθ, Acosθ) from the encoder 120 . Thereby, speed detection can be performed based on a stable position information signal (tanθ, 1/tanθ).

(third embodiment)

Next, a third embodiment of the present invention will be described with reference to FIGS. 7 to 9 .

The basic configuration of the third embodiment is the same as that of the first embodiment, but the third embodiment has its own characteristics in terms of the configuration of the internal position information generation unit.

FIG. 7 is a block diagram showing the configuration of a speed calculation unit in the third embodiment.

In FIG. 7 , it is the same as the first embodiment in that the internal position information generation unit 460 has a first internal position information conversion unit 463 corresponding to the sine signal processing unit 420 , and has a second internal position information conversion unit corresponding to the cosine signal processing unit 430 . The internal position information conversion unit 464 .

Here, in the first embodiment ( FIG. 3 ), there is one integrating unit 461 . Furthermore, when the motor rotational angular velocity (ω ₁ , ω ₂ ) is output from the sine signal processing unit 420 and the cosine signal processing unit 430 respectively, the motor rotational angular velocity (ω ₁ or ω ₂ ) selected by the signal switching unit 450 is input to the integrating part 461. The integrating component 461 integrates the motor rotational angular velocity (ω ₁ or ω ₂ ) and calculates the motor rotational phase. The motor rotation phase (θ _n ) calculated by the integrating unit 461 is output to the first internal position information conversion unit 463 and the second internal position information conversion unit 464, and the internal position information (Asinθ _n , Acosθ _n ).

In this regard, in the third embodiment, a first integrating unit 461A and a second integrating unit 461B are provided as integrating units. That is, in FIG. 7 , a first integrating unit is provided that integrates the motor rotation variation (Δθ ₁ ) output from the sinusoidal signal processing unit 420 based on the sinusoidal signal to calculate the motor rotation phase (θ ₁ ) based on the sinusoidal signal. 461A, and a second integrating unit 461B that integrates the motor rotation variation (Δθ ₂ ) output from the cosine signal processing unit 430 according to the cosine wave signal to calculate the motor rotation phase (θ ₂ ) based on the cosine wave signal.

The first integrating unit 461A integrates the rotation change amount (Δθ ₁ ) of the motor 110 output from the first gain multiplication unit 422 to calculate the motor rotation phase (θ ₁ ). Furthermore, the first integrating unit 461A outputs the calculated motor rotation phase (θ ₁ ) to the first internal position information conversion unit 463 .

The second integrating unit 461B integrates the rotation change amount (Δθ ₂ ) of the motor 110 output from the second gain multiplication unit 432 to calculate the motor rotation phase (θ ₂ ). Furthermore, the second integrating unit 461B outputs the calculated motor rotation phase (θ ₂ ) to the second internal position information conversion unit 464 .

The signal switching unit 450 is the same as the first embodiment in that it includes a judging unit 451 and a switching unit 452, and the switching unit 452 switches the sine-side terminal 453 and the cosine-side terminal 454 with a switching unit. However, here, as the switching unit, It includes a first switching member 452A for speed information output and a second switching member 452B for position information output.

The configuration of the first switching means 452A is the same as that described in the first embodiment. The sine-side terminal 453 and the cosine-side terminal 454 are switched according to the judgment of the judging part 451 to output the motor rotational angular velocity ω _n . This motor rotation angular velocity ω _n (ω ₁ or ω ₂ ) is output to the CPU 310 as a central control unit through the filter 471 .

Also, in the first embodiment, the output signal ω _n (motor rotational angular velocity ω ₁ , ω ₂ ) from the switching unit 452 is input to the integrating unit 461, however, in the third embodiment, the output signal ω n from the third embodiment is not input. 1 The output signal ω _n of the switching section 452A is input to the integrating section (461A, 461B).

The second switching means 452B switches between the sine-side terminal 453 and the cosine-side terminal 454 in accordance with the determination switch means in the determination part 451 .

Here, a signal obtained by sign-converting the motor rotation phase (θ ₁ ) calculated by the first integrating unit 461A by the first sign converting unit 441 is input to the sine-side terminal 453 . Furthermore, a signal obtained by sign-converting the motor rotation phase (θ ₂ ) calculated by the second integrating unit 461B by the second sign converting unit 442 is input to the cosine-side terminal 454 . Then, the output from the second switching unit 452B is output as position information θn (θ ₁ or θ ₂ ) through a filter.

According to the third embodiment having the above configuration, the following effects can be exhibited in addition to the effects of the first embodiment.

When a two-phase signal of a sine wave signal and a cosine wave signal is output from the encoder 12, in the speed calculation unit 400 of the third embodiment, the first integrating unit 461A and The first internal position information conversion unit 463 includes a second integrating unit 461B and a second internal position information conversion unit 464 corresponding to the cosine signal processing unit 430 that processes the cosine wave signal. Thus, when calculating the motor rotation angular velocity _ω1 based on the sine wave signal, the first integrating unit 461A and the first internal position information conversion unit 463 are configured using the motor rotation change amount _Δθ1 based on the sine wave signal as feedback information. In the loop of , the motor rotation angular velocity ω ₁ can be calculated by arithmetic processing based only on the sine wave signal. Similarly, when calculating the motor rotation angular velocity _ω2 based on the cosine wave signal, the second integrating part 461B and the second internal position information conversion part 464 are composed of the motor rotation change amount _Δθ2 based on the cosine wave signal as feedback information. In the loop of , the motor rotation angular velocity ω ₂ can be calculated by arithmetic processing based only on the cosine wave signal.

Here, for example, as in the first embodiment, the motor rotation angular velocity (ω ₁ , ω ₂ ) from the sine signal processing unit 420 and the cosine signal processing unit 430 may be switched and selected by the signal switching unit 450 and input to the integrating unit 461, and The rotational phase (θ _n ) of the motor is calculated by the integrating unit 461 .

However, when the amplitudes of the sine wave and cosine wave output from the encoder 120 are different, a difference occurs between the motor rotational angular velocity _ω1 from the sine signal processing unit 420 and the motor rotational angular velocity _ω2 from the cosine signal processing unit 430. . That is, since A(sinθ- _sinθ1 ) and A'(cosθ- _cosθ2 ) are respectively calculated in the subtracting parts 421, 431 of the sine signal processing part 420 and the cosine signal processing part 430 and the motor rotation is calculated from the difference thereof Angular velocities ω ₁ , ω ₂ , therefore, when the amplitudes (A, A′) of the sine wave and cosine wave are different, the rotational angular velocities ω ₁ , ω ₂ also become different. Furthermore, in the signal switching unit 450, the motor rotation angular velocity (ω ₁ and ω ₂ ) based on the one of the sine wave signal and the cosine wave signal with a larger change in the phase change function value is selected, therefore, the sine wave signal and the cosine The difference in the amplitude of the wave signal tends to become conspicuous. If the significantly different motor rotational angular velocities ω ₁ and ω ₂ are switched in this way and integrated by the integrating unit 461 sequentially, an error tends to be relatively large in the integration of the phase at the time of switching. big.

For example, Fig. 8 shows an example of the motor rotational angular velocity ω output when the amplitude of the sine wave signal Asinθ and the cosine wave signal A'cosθ differ by 5% in the first embodiment. In FIG. 8 , it can be seen that a large error occurs at the timing of signal switching.

In this regard, in the third embodiment, the internal position information on the sine wave signal is calculated by the first integrating unit 461A and the first internal position information conversion unit ₄₆₃ based on the motor rotation variation Δθ1 calculated by the sine signal processing unit 420. , and according to the motor rotation variation _Δθ2 calculated by the cosine signal processing unit 430, the internal position information about the cosine wave signal is calculated by the second integrating unit 461B and the second internal position information conversion unit 464, therefore, from each position information processing unit (The sine signal processing unit 420, the cosine signal processing unit 430) The motor rotational angular velocity ω ₁ , ω ₂ is not affected by the amplitude difference between the sine wave signal and the cosine wave signal.

Here, Fig. 9 is an example of the motor rotational angular velocity ω output when the amplitude of the sine wave signal Asinθ and the cosine wave signal A'cosθ differ by 5% in the configuration of the third embodiment. As shown in FIG. 9 , according to the third embodiment, compared with the first embodiment ( FIG. 8 ), the influence of the amplitude difference between the sine wave signal and the cosine wave signal is suppressed, and the motor rotational angular velocity ω continues relatively smoothly.

(fourth embodiment)

Next, a fourth embodiment of the present invention will be described with reference to FIG. 10 .

The basic structure of the fourth embodiment is the same as that of the first embodiment. However, the fourth embodiment has the following feature that, based on the digital signal converted from the signal from the encoder 120 by the A/D converter, the motor spinning speed.

That is, in FIG. 10 , a first A/D converter 710 for A/D converting the sine wave signal from the encoder 120 and a second A/D converter 710 for A/D converting the cosine wave signal from the encoder 120 are provided. converter 720 .

Furthermore, the speed calculation unit (signal processing unit) 400 has functions such as a position information signal processing unit, a signal switching unit, and an internal position information generating unit, and the above functions are realized by a predetermined signal processing program.

In addition, the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope of achieving the object of the present invention are included in the present invention.

For example, in the first embodiment, the sine signal processing unit 420 and the cosine signal processing unit 430 respectively processing the two-phase signals (Asinθ, Acosθ) output from the encoder 120 are provided, and the signals from the sine signal processing unit 420 are switched and used. The output signal from the cosine signal processing unit 430 and the output signal from the cosine signal processing unit 430 have been described as examples. However, as shown in FIG. The sinusoidal signal processing section 420, and outputs the motor rotational speed (ω ₁ ) based only on the sinusoidal signal (Asinθ). Also, when the sine wave signal (Asinθ) increases and decreases periodically, a sign conversion unit 440 is required for converting the sign of the phase change amount of the motor 110 according to the rotation direction of the motor 110 .

The case where the object of drive control is the motor 110 having the rotor and the speed calculation section (signal processing section) 400 calculates the rotation speed (rotation phase) of the motor 110 from the two-phase signal from the encoder 120 has been described as an example, however, as The driving body is not limited to a motor having a rotor, and may be, for example, a linear motor (Linear Motor) or the like. In particular, in the control of a linear motor, when the time delay greatly affects the control performance, if the signal processing device (speed calculation unit) of the present invention is used to quickly calculate the driving speed and perform speed control based on the calculated driving speed , then there is no phase delay and the control is stable.

Claims (9)

1. A signal processing device for performing signal processing on a position information signal output from a sensor corresponding to a driving position of a driving body and detecting a driving speed of the driving body, characterized in that, have: a position information signal processing unit, which performs signal processing on the position information signal, and calculates driving speed information of the driving body; and an internal position information generating unit reflecting the latest driving speed information calculated by the position information signal processing unit to generate the latest estimated position of the driving body as the internal position information, The position information signal output from the sensor is a periodic function signal that changes periodically corresponding to the driving of the driving body, The position information signal processing unit calculates the phase change amount of the periodic function signal as the driving speed information of the driving body, The internal position information generation unit includes: an integrating unit that integrates the phase change amount from the position information signal processing unit to calculate a phase corresponding to the position information of the driving body; and an internal position information conversion unit, calculating a periodic function value corresponding to the phase calculated by the integrating means as the internal position information, The position information signal processing unit calculates driving speed information of the driving body based on a difference between the position information signal from the sensor and the internal position information generated by the internal position information generating unit. 2. The signal processing device according to claim 1, wherein The periodic function signal is a two-phase signal composed of a first signal and a second signal having a predetermined phase difference with each other, The position information signal processing unit includes: a first signal processing unit that performs signal processing on the first signal and outputs a phase change amount of the first signal as the driving speed information; and a second signal processing unit that performs signal processing on the second signal and outputs a phase change amount of the second signal as the driving speed information, A signal switching unit for switching between the output signal from the first signal processing unit and the output signal from the second signal processing unit is provided on the subsequent stage side of the position information signal processing unit. An output signal of the periodic function signal whose signal value change amount is larger with respect to the amount of phase change. 3. The signal processing device according to claim 2, wherein: The periodic function signal is a sine wave signal, The signal switching unit has: a judging unit that compares the signal value of any one of the first signal and the second signal with a predetermined threshold and judges the magnitude; and The switching means switches between the output signal from the first signal processing unit and the output signal from the second signal processing unit based on a determination result by the determination unit. 4. The signal processing device according to claim 1, wherein: A sign converting unit is provided which converts the sign of the phase change amount output from the position information signal processing unit into a sign indicating an increase or decrease corresponding to the moving direction of the driving body. 5. The signal processing device according to claim 2, wherein: The internal location information generation unit includes: a first integrating unit that integrates a phase change amount of the first signal output from the first signal processing unit to calculate a phase corresponding to the position information of the driving body; a first internal position information conversion unit that calculates a function value of the first signal based on the phase calculated by the first integrating unit; a second integrating unit that integrates a phase change amount of the second signal output from the second signal processing unit to calculate a phase corresponding to the position information of the driving body; and The second internal position information converting unit calculates a function value of the second signal based on the phase calculated by the second integrating means. 6. The signal processing device according to claim 1, wherein: The driving body is a motor having a rotor, and the position information signal output from the sensor is a periodic function signal that changes periodically in response to rotational driving of the motor, The position information signal processing unit outputs a rotational angular velocity as drive speed information of the motor, the integrating means integrates the rotational angular velocity from the position information signal processing unit to calculate a rotational phase angle of the motor, The internal position information conversion unit calculates a periodic function value based on a rotation phase angle of the motor. 7. A signal processing method, carrying out signal processing for the position information signal output from the sensor corresponding to the driving position of the driving body and detecting the driving speed of the driving body, characterized in that it has: A position information signal processing step of performing signal processing on the position information signal, which is a periodic function signal which changes periodically according to the driving of the driving body, and calculating a phase change amount of the periodic function signal; and The internal position information generation step integrates the latest phase change amount calculated in the position information signal processing step, calculates a phase corresponding to the latest estimated position of the driving body, and generates a phase corresponding to the calculated position information. The periodic function value corresponding to the phase is used as the internal position information, The position information signal processing step calculates driving speed information of the driving body based on a difference between the position information signal from the sensor and the internal position information generated by the internal position information generating step. 8. A speed detection device, characterized in that it has: a sensor that outputs a position information signal corresponding to the driving position of the driving body; and The signal processing device according to any one of claims 1 to 6. 9. A servo mechanism, characterized in that it has: drive body; a sensor that outputs a position information signal corresponding to the driving position of the driving body; The signal processing device according to any one of claims 1 to 6; and The central control unit compares the driving speed of the driving body detected by the signal processing device with a predetermined target speed set in advance from outside and controls the driving speed of the driving body to the predetermined target speed.

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