JPH04281381A - Detecting device for momentary position, momentary speed and momentary acceleration of motor, and control method for motor using momentary position value, momentary speed value and momentary acceleration value - Google Patents

Abstract

PURPOSE:To improve a response of a control system by calculating more accurate and less delay momentary position (rotary angle), momentary speed and momentary acceleration in a motor control system using pulse generating means such as a pulse encoder, etc. CONSTITUTION:State observing means 101 estimates a state variable 106 at the time of generating a pulse from pulse generating means immediately before a sampling timing for a state equation with three variables of a rotating speed 102 of a motor, a position 103 of the motor and a load disturbance torque 104 as state variables 106, with a motor torque 105 as a system input and with the position 103 as an output at each sampling timing. Momentary position calculating means 113, etc., detects a momentary value 114 of the position of the motor at the timing based on the equation from the variables 106, and a time difference 108 from the pulse generating time point measured by time difference measuring means 107 to the sampling timing. Accordingly, more accurate momentary values are obtained.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to the instantaneous value and speed of the position (rotation angle) of a motor in motor control using pulse generating means such as a pulse encoder, rotary encoder, or pulse generator as a rotation angle or position detection sensor. The present invention also relates to an acceleration detection device and a method of controlling an electric motor using instantaneous position values, instantaneous velocity values, and instantaneous acceleration values.

0002

[Prior Art and Problems to be Solved by the Invention] In the field of variable speed drive of electric motors using power electronics, due to the demand for higher performance, higher reliability, and higher functionality of control, digital Control methods are increasingly being adopted.

In many cases, it is necessary to perform highly accurate speed detection, acceleration detection, or position (rotation angle) detection from the viewpoint of control accuracy, and so-called pulse generators, pulse encoders, or rotary encoders (hereinafter referred to as encoders) are used. The position (rotation angle) of the electric motor is directly detected using this method, and the speed and acceleration of the electric motor are detected by using the detected value to obtain a physical quantity called frequency.

However, in the method using an encoder as described above, as shown in FIG. 9, the encoder converts the rotation angle θ, which is originally a continuous quantity, into extremely rough discrete values defined by the resolution of the encoder. Output as integrated value θn. Therefore, any sampling timing t
In the detected value θn at (for example, t1 in FIG. 9), there is a macroscopic detection delay (for example, the dead time Δt in FIG. 9).
1) occurs, and microscopically, a quantization error of up to one quantization width occurs at the encoder resolution with respect to the true rotation angle (for example, "θ(t1) - θ(t1 - Δt1" in Figure 9).
)”). Therefore, for example, when controlling the rotation angle or position using encoder output, there are problems such as deterioration of control response and loss of stability and control accuracy due to detection delay and quantization error. have.

On the other hand, methods of speed detection using encoder output include: 1) counting the number of pulses generated by the encoder within a certain period and dividing it by the counted period (time); 2) counting the pulses generated by the encoder There is a method of measuring the interval (period) between pulses and taking the reciprocal of the pulse to obtain the speed. In addition, for example, in the method disclosed in ``Japanese Unexamined Patent Publication No. 58-48868,'' the number of pulses within a certain sampling period and the net time required to generate the pulses are measured, and the number of pulses is then calculated. Highly accurate speed detection is realized by dividing the speed. However, the speed detection values obtained by these methods are all values obtained as a result of measuring the average speed within each measurement period, and compared to speed detection using a conventional speed generator, the speed detection value is The value will include a delay due to time averaging,
This poses a problem in that it causes various adverse effects on the response and stability of the control system.

[0006] Therefore, in "Unexamined Japanese Patent Publication No. 2-7887", "
In addition to the average speed detected using the method disclosed in JP-A No. 58-48868, the instantaneous speed at the sampling point is calculated from the load disturbance torque and motor output torque estimated based on state observer logic. I try to ask for it. In this method, once the average speed is determined, the instantaneous speed is calculated. However, counting the output pulses of a pulse generator as a speed sensor means measuring the rotation angle of the motor shaft within the counting period, and the speed obtained by dividing this by time is literally the average speed. This is similar to and different from the motor speed ω that appears in the equation of state that describes the transient phenomena of the motor. In other words, average velocity is one of the concepts used to express phenomena, and is not necessarily appropriate for describing actual physical phenomena, especially transient phenomena. For example, even if the average velocity is the same in the acceleration process and in the deceleration process, the physical phenomena (for example, the instantaneous velocity at the start and end points of the time averaging period) are completely different, and such an average There are naturally limits to calculating future instantaneous speed from speed.

[0007] In addition, in motion control for servos, etc., instead of the conventional speed control system that has a current control system in a minor loop, a method of configuring an acceleration control system that focuses on a state quantity called acceleration has been proposed by an academic society. It has been published in papers, etc. (for example, Hori: "Proposal of an acceleration-controlled servo system", Journal of the Institute of Electrical Engineers of Japan, D, 107, 1986-12). In this case, the most common method for detecting acceleration is to differentiate the output of a speed generator (tacho generator) in the form of an analog signal, but since differential operation is sensitive to noise, pure differential It is difficult to apply the behavior. Therefore, in reality, velocity obtained by incompletely differentiating it using an analog circuit is used as acceleration. Alternatively, if the control system is configured as a digital system, the acceleration may be calculated by software calculation processing. However, these methods have problems in that it is difficult to obtain an ideal amount of acceleration, and the obtained acceleration includes a delay. In particular, when speed detection is performed using a pulse generator, it is virtually impossible to directly detect acceleration.

On the other hand, especially in digital control systems consisting of sample value control, a method that applies state observer theory, which is one of the modern control theories, to motor control is as follows:
There is a method of estimating the load disturbance torque of an electric motor using a state observer. In this condition observation device, for example, the actual output torque value of the motor or the torque command value to the power converter is used as an input to the electric-mechanical model of the motor. The first way to use these methods is to drive the model in the condition observation device using the actual value of the torque that actually dynamically drives the motor. In some cases, the actual torque value cannot be directly detected, or even if it can be detected, the detected value contains large ripples that cause disturbance to the control system, or the response of the current control system is fast, such as with a transistor inverter. In cases where the command value can be considered as the actual value, the instantaneous value or average value of the torque command value to the power converter is used as an input to the condition observation device. However, this method has a problem in that the dynamics from the electrical system to the mechanical system is not considered.

In addition, in a digital control system using a microcomputer, detection of state quantities of a controlled object, control calculations, etc. are performed in chronological order, so there is dead time from detection to control, and the detected value Coupled with the delay involved (see FIG. 9), this poses a problem in that control performance is impaired or sufficient control performance cannot be demonstrated.

An object of the present invention is to improve the response of a control system by making it possible to calculate instantaneous position (rotation angle), instantaneous velocity, and instantaneous acceleration with more accuracy and less delay.

[0011]

[Means for Solving the Problems] The present invention provides position detection means for detecting the position or rotation angle of an electric motor based on pulses from a pulse generating means such as a pulse encoder, a rotary encoder, or a pulse generator attached to the electric motor. This assumes an electric motor control device with a The means is, for example, a counter that counts encoder pulses, and the counter is reset, for example, at each sampling timing, and calculates an integrated value of encoder pulses in each sampling period.

FIG. 1 is a block diagram of the invention according to a first aspect of the invention. The time difference measuring means 107 measures, at each sampling timing, the time difference 108 from the point in time when a pulse is generated from the immediately preceding pulse generating means to the sampling timing.

The state observation means 101 monitors the rotation speed 102, position or rotation angle 103, and load disturbance torque 10 of the motor.
4 are the state variables 106, the system input is the motor torque 105, and the system output is the position or rotation angle 103.
For the state equation, the time difference 1 measured by the time difference measuring means 107 at each sampling timing is
08, the state variable 106 at the time of generation of the pulse from the pulse generation means immediately before is estimated. This estimation is performed based on the state variables estimated at the previous sampling timing.

The instantaneous position calculation means 113 calculates the electric motor at each sampling timing based on a state equation based on the state variable 106 estimated by the state observation means 101 and the time difference 108 measured by the time difference measurement means 107. An instantaneous value 114 of the position or rotation angle is calculated. The calculation in this case is performed using an expression determined from a transition matrix derived from a state equation.

Here, instead of the instantaneous position calculating means 113, it is also possible to have an instantaneous speed calculating means 109 for calculating the instantaneous value 110 of the speed of the electric motor at the sampling timing.

Furthermore, instead of these, it is also possible to have an instantaneous acceleration calculation means 111 for calculating the instantaneous value 112 of the acceleration of the electric motor at the sampling timing.

Furthermore, the instantaneous position calculating means 113, the instantaneous velocity calculating means 109, or the instantaneous acceleration calculating means 111 can be arbitrarily combined. Next, a second aspect of the present invention will be explained. In the second aspect, the state variables 106 in the first aspect are the rotation speed 102, position or rotation angle 103 of the electric motor, and load disturbance torque 1.
Four variables are used, which are the three variables of 04 and the electric motor torque. The output of the system is the position or rotation angle 103 as in the first aspect, but the difference is that the input of the system is the command value of the motor torque.

Next, a third aspect of the present invention will be explained. In the third aspect, in the first aspect or the second aspect of the present invention described above, the instantaneous velocity calculation means or the instantaneous acceleration calculation means is not performed at each sampling timing,
The system is configured to calculate the instantaneous value of the position, rotation angle, velocity, or acceleration at a time delayed by a predetermined time corresponding to the time required for control calculations, etc.

[0019]

[Operation] In the present invention, in a motor control system using a pulse generating means such as a pulse encoder as a sensor for detecting a position or a rotation angle, the operation of the pulse generating means quantizes the rotation angle of the motor with extremely coarse resolution. However, focusing on the fact that the output rotation angle information matches the actual rotation angle of the motor at the time the pulse is generated from the pulse generation means, By constructing the state equation of Since the instantaneous position, rotation angle, and instantaneous velocity are estimated, more accurate instantaneous values can be obtained that do not include wasted time for detection.

Furthermore, in the conventional method, when the integrated value of pulses from the pulse generating means is used as it is, the detection resolution of the position or rotation angle is an integer value, which is the same as the resolution of the pulse generating means. The instantaneous value of the position or rotation angle obtained at each sampling timing can be obtained apparently as a continuous quantity including decimal points, apart from the accuracy of the estimation calculation. Therefore, it is not affected by quantization errors caused by the resolution of the pulse generating means as in the prior art.

On the other hand, since the acceleration is determined by calculation from other state variables without relying on velocity differentiation, problems associated with differential operation can be avoided, and instantaneous acceleration without delay can be obtained.

Furthermore, by extending this idea and calculating the instantaneous value at the point in time delayed by the dead time required for calculations in the control system and using this in the control calculation, it is possible to eliminate The response of the control system can be improved.

[0023]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, before describing specific embodiments, the basic structure and operating principle of the embodiments of the present invention will be explained.

FIG. 2 is a first principle configuration diagram of an embodiment according to the present invention. As can be seen from the system shown in the figure, in the first principle configuration, the motor speed ω, the load disturbance torque τ
d and the rotation angle θ of the motor converted to the integrated output pulse value of the encoder are set as the state variable vector χ1. Then, the motor torque τM is selected as the input of the system, and the rotation angle θ of the motor is selected as the output of the system. In the timing chart of FIG.

[0025]

[Outside 1]

(substituted by "χ1'") is calculated using the state observer algorithm shown in equation (3) of equation 2 below. Next, sampling timing t=
The instantaneous value of the rotation angle (position) θ of the motor at t1 is
The estimated value χ1' of the state variable is applied to the equation (4) of the following equation 2, which is formed by the transition matrix Φ derived from the state equation of equation (1) of the equation 1, and calculated. Further, the instantaneous value of the speed ω of the electric motor at the sampling timing t=t1 is obtained from the estimated value χ1' of the state variable by an algebraic operation expressed by the following equation (5) of Equation 2. Furthermore, the instantaneous value of the acceleration dω/dt of the electric motor is determined from the above estimated value χ1' by algebraic calculations expressed by the following equations (6a) and (6b).

[0027]

[Math 1]

[0028]

[Math 2]

The operation of the above-mentioned first principle configuration will be explained. Now, the integrated value θn of the encoder pulses as a rotation angle sensor of the electric motor is as described above in FIG.
Due to quantization defined by the resolution of the encoder, the true rotation angle θ includes a quantization error expressed by the following equation (7).

[0030] θn ≦θ≦θn +1
・
...(7) That is, the integrated value θn of encoder pulses
contains an error equivalent to a maximum of one quantization width. Therefore, if this is used as is, accurate position (rotation angle) detection cannot be performed. Furthermore, when speed detection is performed by calculating frequency information based on the output of the encoder, the speed amount obtained by the calculation is only the time integral divided by time, that is, the average value, and correct speed detection and Furthermore, acceleration cannot be detected.

However, the original operation of an encoder that generates pulses at every fixed rotation angle is an integral operation, and the integrated value θn of encoder output pulses obtained from this is an integral operation.
As is clear from Fig. 9, at the time of occurrence of the encoder pulse (for example, t = t1 - Δt1 in Fig. 9), is completely different from the actual physical quantity of the true rotation angle θ, regardless of the quantization error or encoder resolution. Match. The differential of the integrated value θn at that point is nothing but the motor speed. Focusing on this fact, if we consider the rotation angle of the motor at the time of input of the encoder pulse as the output of the state equation that describes the system instead of the speed or average speed that has been conventionally used, we can obtain the equation of Equation 1. (1
), (2) The relationship expressed by the equation of state holds true. In other words, at the input point of the encoder pulse, the state variable vector χ1 is calculated using the integrated value θn of the encoder pulse, which is directly detectable and reliable information, based on the control theory regarding the state observer described below. can be estimated. Here, "reliable" means that other state variables other than rotational angle (position) θ, such as rotational speed ω, measured using a pulse encoder are calculated by dividing the integrated value θn of encoder pulses by time, that is, the average value. The velocity ω, which is nothing but the velocity and appears in the state equations (1) and (2),
is not necessarily an equivalent state quantity, but it means that at the time of encoder pulse input, the integrated value θn of encoder pulses exactly matches the output θ appearing in state equations (1) and (2). It is.

In control theory, if equations (1) and (2) are observable, it is possible to estimate the state variable vector χ1 from the output y1 of the system, and from the state at any time, the subsequent The state can be calculated a priori. Therefore, we will verify the observability of equations (1) and (2).

The necessary and sufficient condition for the system expressed by the state equations (1) and (2) to be observable is the following equation 3. rank) is equal to the order (in this case, 3) of the matrix A1 (see Equation 1).

[0034]

[Math 3]

Therefore, the state equations (1) and (2
) is observable and has a coefficient matrix K
By appropriately selecting 1, the state variable vector χ1 can be estimated with an arbitrary response based on Equation (3) of Equation 2. Therefore, t=t in the timing chart of FIG.
At the sampling timing shown by 1, the rotation angle θ of the motor in the state equation of equation (1) converted to the number of encoder pulses is t=t0 −Δt0 ~t
= t1 - Δt1 (not necessarily an integer, and does not have to be) and the integrated value θn of encoder pulses generated between the current sampling timing t=t0 and t1 (needless to say, θn is t = t1 - Δt
The estimated value χ1' of the state variable at time 1 is calculated.

Next, from the estimated value χ1' of the state variable at the time t=t1 - Δt1, the estimated value χ1' of the state variable at t=t1 is calculated based on equation (9) of Equation 4 below.

[0037]

[Math 4]

Specifically, from equation (9), equation (4) of the above-mentioned equation 2 is obtained, and thereby the instantaneous position (instantaneous value of rotation angle) θ at t=t1 is obtained. In addition, (9
) The formula is for the case where t=t1 -Δt1 to t1 and τM is constant.

Furthermore, from equation (9), (5
) is obtained, which gives the instantaneous velocity ω at t=t1 (τM assumed as above). Furthermore, from equation (9), equation (6a) of the above-mentioned equation 2 can be obtained,
As a result, the instantaneous value of τd at t=t1 is calculated (τM is assumed as above), and the equation (1) of Equation 1 is calculated.
(6b) of Equation 2 above, which is part of the state equation of Eq.
According to the formula, acceleration dω/dtt= at t=t1
t1 can be found.

A method of determining the subsequent state from the state (state variable) of the system at an arbitrary point in time using equation (9) of Equation 4 is well known. ) etc.

Next, FIG. 3 shows a second embodiment of the present invention.
FIG. As can be seen from the system shown in the figure, in the second principle configuration, the motor torque τ is added to the component of the state variable vector χ1 shown in the first principle configuration.
M has been added. Then, using the system input as the torque command value τ* of the control device instead of the motor torque τM, the following Equations (10) and (11) of Equation 5 are used.
By assuming the state equation expressed by the following equation and performing the same calculations as in the first principle configuration, the instantaneous values of the motor rotation angle (position) θ, speed ω, and acceleration dω/dt at the sampling time are obtained. Desired. That is, based on the state observer algorithm expressed by Equation (12) of Equation 6 below, the estimated value of the state variable vector at the encoder pulse generation time (t=t1 - Δt1) immediately before sampling timing t=t1 is calculated. 2 (hereinafter,
In the text

[0042]

[Outside 2]

[0043] "χ2'" is substituted. ) is calculated, and furthermore, the instantaneous value of the rotation angle (position) θ of the motor at the sampling timing t=t1 is calculated by applying the estimated value χ2' of the state variable to Equation (13) of Equation 6. It will be done. Also, sampling timing t=t1
The instantaneous value of the speed ω of the electric motor at is determined from the estimated value χ2' of the state variable by an algebraic operation expressed by the following equation (14) of Equation 6. Furthermore, the acceleration of the electric motor dω/
The instantaneous value of dt is calculated from the estimated value χ2' of the state variable vector χ2 at sampling timing t=t1 using Equation 6.
It is obtained by algebraic operations expressed by equations (15a), (15b), and (15c).

[0044]

[Math 5]

[0045]

[Math 6]

As for the equation of state in the second principle configuration expressed by equations (10) and (11) of Equation 5 above, as in the case of the first principle configuration, if these are observable, then State variable vector χ2 from system output y2
It is possible to estimate the following state, and the subsequent state can be calculated a priori from the state at any time. Therefore, (1
Regarding the observability of equations 0) and (11), the equation (
8) When verified in the same manner as Equation 8), the following Equation (16) is obtained.

[0047]

[Math 7]

Therefore, the system in the second principle configuration expressed by the state equations (10) and (11) of Equation 5 is also observable, and the state variables can be estimated by a state observer and Subsequent state variables can be calculated a priori from a state variable. That is, the estimated value χ2' of the state variable vector χ2 at t=t1 is expressed by the following equation 8.
It can be obtained using equations (17) and (18).

[0049]

[Math. 8]

From equation (17), equation (13) of the above-mentioned equation 6,
Equations (14), (15a), (15b) are obtained, and t=
The instantaneous values of τM and τd at t1 are calculated, and the instantaneous position (rotation angle) θ and instantaneous velocity ω at t=t1 are determined.

Furthermore, from the instantaneous values of τM and τd mentioned above, the acceleration dω/ dtt=t1 can be obtained.

Next, the third basic configuration of the present invention will be explained. Although the third principle configuration is not specifically illustrated, it is configured as an extension of the above-described first principle configuration or second principle configuration.

[0053] In the third principle configuration, the above-mentioned first or second
In the principle configuration, the instantaneous position (
The times of rotation angle), instantaneous velocity, and instantaneous acceleration are at the start of the sampling period, that is, at the sampling timing t=t1
Instead, it is assumed that the time t=t1 +Δtc is delayed by the time Δtc required for the detection calculation of each instantaneous value and the system control calculation based on the calculation (see Figure 4), and each instantaneous value at that point is The values are calculated and used for system control calculations. This is the feature of the third principle configuration.

That is, in each algorithm of the first or second principle configuration described above, from the estimated value of the state variable at the time of the last encoder pulse generation within the measurement (sampling) period,
The instantaneous value at the start of the immediately subsequent sampling period was predictively calculated based on the state equation. However, the instantaneous value can be calculated in the same way even if the predicted time is not set as the start time of the sampling period but delayed by the time required for various detection calculations, control calculations, etc. Therefore, in the third principle configuration, this is used to calculate the instantaneous position (rotation angle), instantaneous velocity, and instantaneous acceleration at a time delayed from the sampling timing so that the dead time existing in the control system is canceled. By using this method, it is possible to improve the control response caused by these wasted times.

The specific configuration of the embodiment of the present invention based on the first to third principle configurations will be described in detail above. Figure 5
4 shows a configuration diagram of a specific embodiment of the present invention, and FIG. 4 shows its operation timing chart.

[0056] Position attached to motor shaft (rotation angle)
The two-phase pulses A and B of the encoder for detection are sent to the up-down counter 502 as an up-count signal Pup or down-count in the phase discrimination circuit 501, depending on the phase of the two-phase pulses determined by the rotational direction of the motor. It is converted into a signal Pdown.

The up/down counter 502 receives the up count signal Pup and the down counter signal Pdown.
As a result, the encoder pulses are integrated with positive values in the forward direction and negative values in the reverse direction, and the counter is reset to 0 by the sampling timing signal S generated at a constant period Ts.

The time measurement counter 503 functions as a time measurement device converted into a system clock by counting the system clock F having a constant frequency, and outputs an up count signal Pup and a down count signal Pdown.
It is reset to 0 by the OR signal of .

Data latches 504 and 505 respectively latch the integrated value θn of the up/down counter 502 and the count value Δt of the time measurement counter 503 immediately before being reset by the sampling timing signal S.

The microcomputer 506, in a program started at a constant period Ts by the sampling timing signal S, calculates the integrated value θn of encoder pulses held in the data latches 504 and 505 via the data bus 507 and the time counter 503. The count value Δt is read, and detection calculations and control calculations for instantaneous position (rotation angle), instantaneous velocity, instantaneous acceleration, etc. are performed using an algorithm as described below.

Note that the power converter for actually driving the electric motor, its control algorithm, etc. are not directly covered by the present invention, so illustrations and explanations thereof are omitted here for the sake of brevity.

In the configuration of the above-described specific embodiment, a first example of the processing operation executed by the microcomputer 506 will be explained with reference to the program flowchart shown in FIG. This processing operation corresponds to the first principle operation of the present invention described above.

In the program shown in the flowchart of FIG. 6 in which the microcomputer 506 is activated by the sampling timing signal S, the following steps are sequentially executed.

First, the integrated value θn of encoder pulses held in the data latches 504 and 505 and the count value Δt1 of the time counter 3 are read (step S1).

Net time tw from the encoder pulse input point immediately before the previous sampling timing to the encoder pulse input point immediately before the current sampling timing
is the previous value Δt0 and the current value Δt of the count value of the time measurement counter 503 held in the data latch 505.
1 by the following equation (19) (step S
2).

tw =Δt0 +Ts−Δt1
・・・
...(19) However, Ts: estimated value χ1' of the state variable vector at the previous sampling period t = t0 - Δt0 and encoder pulse count number θn
From tw and the like obtained in step S2, the estimated value χ1' of the state variable vector at this time t=t1 -Δt1 is estimated based on equation (3) of Equation 2 (
Step S3).

Based on equations (4), (5), (6a) and (6b), the current sampling timing t=t1 is determined using the state variable vector χ1' (t1 - Δt1) estimated in step S3 above. The instantaneous position (rotation angle) θ, instantaneous velocity ω, and instantaneous acceleration dω/dt are calculated at (step S4).

Next, a second example of the processing operation executed by the microcomputer 506 will be explained with reference to the program flowchart shown in FIG. This processing operation corresponds to the second principle configuration of the present invention described above.

In the program shown in the flowchart of FIG. 7 in which the microcomputer 506 is activated by the sampling timing signal S, the following steps are sequentially executed.

The integrated value θn of encoder pulses held in the data latches 504 and 505 and the count value Δt1 of the time measurement counter 503 are respectively read (step S5).

Net time tw from the encoder pulse input point immediately before the previous sampling timing to the encoder pulse input point immediately before the current sampling timing
is the previous value Δt0 and the current value Δt of the count value of the time measurement counter 503 held in the data latch 505.
1 by the above-mentioned equation (19) (step S6).

The estimated value χ2' of the state variable vector at the previous time t=t0 -Δt0, the encoder pulse count number θn, and the t obtained in step S6
From w etc., the estimated value χ2' of the state variable vector at the current time t=t1 -Δt1 is estimated based on Equation (12) of Equation 6 (Step S7).

(13), (14), (15a), (15
b) and (15c) Based on formulas, the above step S
The state variable vector χ2'(t1 −Δ
t1), the current sampling timing t=t
1, the instantaneous position (rotation angle) θ, instantaneous velocity ω, and instantaneous acceleration dω/dt are calculated.

Finally, a third example of the processing operation executed by the microcomputer 506 will be explained with reference to the program flowchart shown in FIG. This processing operation corresponds to the third principle configuration of the present invention described above.

In the program shown in the flowchart of FIG. 8 in which the microcomputer 506 is activated by the sampling timing signal S, the following steps are sequentially executed.

The integrated value θn of encoder pulses held in the data latches 504 and 505 and the count value Δt1 of the time measurement counter 503 are respectively read (step S9).

Net time tw from the encoder pulse input point immediately before the previous sampling timing to the encoder pulse input point immediately before the current sampling timing
is the previous value Δt0 and the current value Δt of the count value of the time measurement counter 503 held in the data latch 505.
1 by the above-mentioned equation (19) (step S10).

From the estimated value χ1' or χ2' of the state variable vector at the previous time t=t0 - Δt0, the pulse count number θn of the encoder, tw obtained in step S10, etc., the state variable vector at the current time t=t1 - Δt1 is calculated. The estimated value χ1' or χ2' is estimated based on Equation (3) of Equation 2 or Equation (12) of Equation 6 (Step S11).

(4), (5), (6a), (6b) or (13), (14), (15a), (15b), (
15c) Based on the equation, state variable vector χ1'(t1-Δt1) or χ2'(t1-Δt1) at t=t1-Δt1 estimated in step S11 above.
Δt' expressed by the following equation (20) using Δt1)
The instantaneous position (rotation angle) θ, instantaneous velocity ω, and instantaneous acceleration dω/dt at the time delayed by t=t1 +Δtc are calculated (step S12).

[0080] Δt' = Δt1 + Δtc
・・・
...(20) However, Δtc: Dead time of the control system due to detection, control calculation, etc. t=t1 +Δtc found in step S12 above
Control calculations are performed using the instantaneous position (rotation angle) θ, instantaneous velocity ω, and instantaneous acceleration dω/dt at .

The specific embodiments described above realize the characteristic operations of the present invention based on the first to third principle configurations described above.

[0082]

According to the present invention, in a motor control system using a pulse generating means such as a pulse encoder as a sensor for detecting a position or rotation angle, the operation of the pulse generating means can detect the rotation angle of the motor with extremely high resolution. Although it is output as coarse quantized information, we focused on the fact that the output rotation angle information matches the actual rotation angle of the motor at the time the pulse is generated from the pulse generation means, and By constructing the state equation, the state variables (instantaneous values) of the system at the time of the pulse generation can be estimated using a state observation device that is more in line with the actual physical phenomenon, and from there, Since the instantaneous position, rotation angle, and instantaneous velocity are estimated, it is possible to obtain more accurate instantaneous values that do not include wasted time for detection.

Furthermore, whereas conventionally, when the integrated value of pulses from the pulse generating means was used as it was, the detection resolution was an integer value that corresponded to the resolution of the pulse generating means, whereas the sampling timing obtained by the present invention was Apart from the accuracy of the estimation calculation, the instantaneous value for each can be obtained as a seemingly continuous quantity including decimal points. For this reason, it has the effect of not being affected by quantization errors caused by the resolution of the pulse generating means as in the prior art.

On the other hand, since the acceleration is determined by calculation from other state variables without relying on velocity differentiation, problems associated with differential operation can be avoided, and instantaneous acceleration without delay can be obtained.

Furthermore, by extending this idea and calculating the instantaneous value at the point in time delayed by the dead time required for calculations in the control system and using this in the control calculation, it is possible to eliminate This makes it possible to improve the response of the control system.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the invention according to a first aspect of the invention.

FIG. 2 is a first principle configuration diagram of an embodiment of the present invention.

FIG. 3 is a second principle configuration diagram of an embodiment of the present invention.

FIG. 4 is a timing chart of an embodiment of the present invention.

FIG. 5 is a configuration diagram of a specific embodiment of the present invention.

FIG. 6 is a first processing operation flowchart of a specific example.

FIG. 7 is a second processing operation flowchart of a specific example.

FIG. 8 is a third processing operation flowchart of a specific example.

FIG. 9 is an explanatory diagram of problems in the conventional example.

[Explanation of symbols]

101 Status observation means 102 Rotational speed of electric motor 103 Motor position 104 Load disturbance torque 105 Electric motor torque 106 State variables 107 Time difference measuring means 108 Time difference 109 Instantaneous speed calculation means 110 Instantaneous speed value 111 Instantaneous acceleration calculation means 112 Instantaneous acceleration value 113 Instantaneous position calculation means 114 Instantaneous position value

Claims (14)

[Claims] 1. In a motor control device having a position detection means for detecting the position or rotation angle of the motor based on pulses from a pulse generation means attached to the motor, the pulse generation means immediately before the pulse generation is detected at each sampling timing. A time difference measuring means (107) for measuring the time difference (108) from the time point when a pulse is generated from the means to the sampling timing, and the rotation speed (102), position or rotation angle (103) of the electric motor, and load disturbance torque (104). For the state equation in which the three variables are the state variables (106), the system input is the motor torque (105), and the system output is the position or rotation angle (103), at each sampling timing, the pulse immediately before the state variable (106) at the time of generation of the pulse from the generation means;
from the state variable (106) estimated by the state observation means (101) and the time difference (108) measured by the time difference measurement means (107) at each sampling timing. An instantaneous position detecting device for an electric motor, comprising an instantaneous position calculating means (113) for calculating an instantaneous value (114) of the position or rotation angle of the electric motor at the sampling timing based on the state equation. 2. In a motor control device having a position detection means for detecting the position or rotation angle of the motor based on pulses from a pulse generation means attached to the motor, at each sampling timing, the pulse generation means immediately before the A time difference measuring means (107) for measuring the time difference (108) from the time point when a pulse is generated from the means to the sampling timing, and the rotation speed (102), position or rotation angle (103) of the electric motor, and load disturbance torque (104). For the state equation in which the three variables are the state variables (106), the system input is the motor torque (105), and the system output is the position or rotation angle (103), at each sampling timing, the pulse immediately before the state variable (106) at the time of generation of the pulse from the generation means;
from the state variable (106) estimated by the state observation means (101) and the time difference (108) measured by the time difference measurement means (107) at each sampling timing. An instantaneous speed detection device for a motor, comprising: instantaneous speed calculation means (109) for calculating an instantaneous value (110) of the speed of the motor at the sampling timing based on the state equation. 3. In a motor control device having a position detecting means for detecting the position or rotation angle of the motor based on pulses from a pulse generating means attached to the motor, the pulse generation means immediately before each sampling timing is detected. A time difference measuring means (107) for measuring the time difference (108) from the time point when a pulse is generated from the means to the sampling timing, and the rotation speed (102), position or rotation angle (103) of the electric motor, and load disturbance torque (104). For the state equation in which the three variables are the state variables (106), the system input is the motor torque (105), and the system output is the position or rotation angle (103), at each sampling timing, the pulse immediately before the state variable (106) at the time of generation of the pulse from the generation means;
from the state variable (106) estimated by the state observation means (101) and the time difference (108) measured by the time difference measurement means (107) at each sampling timing. An instantaneous acceleration detection device for an electric motor, comprising an instantaneous acceleration calculation means (111) for calculating an instantaneous value (112) of the acceleration of the electric motor at the sampling timing based on the state equation. 4. In a motor control device having a position detection means for detecting the position or rotation angle of the motor based on pulses from a pulse generation means attached to the motor, at each sampling timing, the immediately preceding pulse generation is detected. A time difference measuring means that measures the time difference from the time when a pulse is generated from the means to the sampling timing, and four variables of the motor rotation speed, position or rotation angle, motor torque, and load disturbance torque are used as state variables, and the system input is state observation means for estimating the state variable at the time point at which a pulse is generated from the pulse generation means immediately before each sampling timing, with respect to a state equation in which the torque command value and system output are the position or rotation angle; and, for each sampling timing, calculate the instantaneous value of the position or rotation angle of the motor at the sampling timing based on the state equation from the state variable estimated by the state observing means and the time difference measured by the time difference measuring means. An instantaneous position detecting device for an electric motor, comprising instantaneous position calculating means for calculating. 5. In a motor control device having a position detection means for detecting the position or rotation angle of the motor based on pulses from a pulse generation means attached to the motor, at each sampling timing, the immediately preceding pulse generation is detected. A time difference measuring means that measures the time difference from the time when a pulse is generated from the means to the sampling timing, and four variables of the motor rotation speed, position or rotation angle, motor torque, and load disturbance torque are used as state variables, and the system input is state observation means for estimating the state variable at the time point at which a pulse is generated from the pulse generation means immediately before each sampling timing, with respect to a state equation in which the torque command value and system output are the position or rotation angle; and an instant for calculating an instantaneous value of the speed of the electric motor at each sampling timing based on the state equation from the state variable estimated by the state observing means and the time difference measured by the time difference measuring means. An instantaneous speed detection device for an electric motor, comprising speed calculation means. 6. In a motor control device having a position detection means for detecting the position or rotation angle of the motor based on pulses from a pulse generation means attached to the motor, the pulse generation means immediately before the pulse generation means is detected at each sampling timing. A time difference measuring means that measures the time difference from the time when a pulse is generated from the means to the sampling timing, and four variables of the motor rotation speed, position or rotation angle, motor torque, and load disturbance torque are used as state variables, and the system input is state observation means for estimating the state variable at the time point at which a pulse is generated from the pulse generation means immediately before each sampling timing, with respect to a state equation in which the torque command value and system output are the position or rotation angle; and an instant for calculating the instantaneous value of the acceleration of the electric motor at each sampling timing based on the state equation from the state variable estimated by the state observing means and the time difference measured by the time difference measuring means. An instantaneous acceleration detection device for an electric motor, comprising: acceleration calculation means. 7. In a control device for a motor having a position detection means for detecting the position or rotation angle of the motor based on pulses from a pulse generation means attached to the motor, at each sampling timing, the immediately preceding pulse generation is detected. A time difference measuring means for measuring the time difference from the time when a pulse is generated from the means to the sampling timing, three variables of the rotation speed, position or rotation angle of the electric motor, and load disturbance torque are used as state variables, and the system input is the electric motor torque,
a state observation means for estimating the state variable at the time of generation of a pulse from the pulse generation means immediately before each sampling timing, for a state equation in which the system output is the position or the rotation angle; and the sampling timing At each time, the position or rotation angle of the electric motor at a time point further delayed by the predetermined time from the sampling timing is determined based on the state equation from the state variable estimated by the state observation means and the time difference measured by the time difference measurement means. instantaneous position calculation means for calculating the instantaneous value of the instantaneous position value, and the instantaneous position value or rotation angle value calculated by the instantaneous position calculation means is used for control calculation of the electric motor. A method of controlling electric motors. 8. In a motor control device having a position detection means for detecting the position or rotation angle of the motor based on pulses from a pulse generation means attached to the motor, at each sampling timing, the immediately preceding pulse generation is detected. A time difference measuring means for measuring the time difference from the time when a pulse is generated from the means to the sampling timing, three variables of the rotation speed, position or rotation angle of the electric motor, and load disturbance torque are used as state variables, and the system input is the electric motor torque,
a state observation means for estimating the state variable at the time of generation of a pulse from the pulse generation means immediately before each sampling timing, for a state equation in which the system output is the position or the rotation angle; and the sampling timing Based on the state equation from the state variable estimated by the state observation means and the time difference measured by the time difference measurement means, the instantaneous value of the speed of the motor at a time point further delayed by the predetermined time from the sampling timing is calculated. instantaneous velocity calculation means for calculating the
A method for controlling an electric motor using an instantaneous speed value, characterized in that the instantaneous speed value calculated by the instantaneous speed calculating means is used for control calculation of the electric motor. 9. In a control device for a motor having a position detection means for detecting the position or rotation angle of the motor based on pulses from a pulse generation means attached to the motor, at each sampling timing, the immediately preceding pulse generation is detected. A time difference measuring means for measuring the time difference from the time when a pulse is generated from the means to the sampling timing, three variables of the rotation speed, position or rotation angle of the electric motor, and load disturbance torque are used as state variables, and the system input is the electric motor torque,
a state observation means for estimating the state variable at the time of generation of a pulse from the pulse generation means immediately before each sampling timing, for a state equation in which the system output is the position or the rotation angle; and the sampling timing At each time, based on the state equation from the state variable estimated by the state observation means and the time difference measured by the time difference measurement means, the instantaneous value of the acceleration of the motor at a time point further delayed by the predetermined time from the sampling timing. A method for controlling an electric motor using an instantaneous acceleration value, characterized in that the instantaneous acceleration value calculated by the instantaneous acceleration calculation means is used for control calculation of the electric motor. 10. In a control device for an electric motor having a position detection means for detecting the position or rotation angle of the electric motor based on pulses from a pulse generation means attached to the electric motor, at each sampling timing, the pulse generation means immediately before the time difference measuring means for measuring the time difference from the time point at which the pulse is generated from the means to the sampling timing;
For a state equation in which the three variables of motor rotation speed, position or rotation angle, and load disturbance torque are state variables, the system input is the motor torque, and the system output is the position or rotation angle, at each sampling timing, a state observation means for estimating the state variable at the time of generation of a pulse from the pulse generation means immediately before; and instantaneous position calculation means according to claim 7, instantaneous velocity calculation means according to claim 8, or instantaneous velocity calculation means according to claim 9. and at least one of the instantaneous acceleration calculation means described above, the instantaneous position value or rotation angle value calculated by the instantaneous position calculation means, the instantaneous velocity value calculated by the instantaneous velocity calculation means, or the instantaneous acceleration calculation A method for controlling an electric motor using at least one of an instantaneous position value, an instantaneous velocity value, or an instantaneous acceleration value, characterized in that at least one of the instantaneous acceleration values calculated by the means is used for control calculation of the electric motor. 11. In a motor control device having a position detecting means for detecting the position or rotation angle of the motor based on pulses from a pulse generating means attached to the motor, the pulse generation means immediately before each sampling timing is detected. time difference measuring means for measuring the time difference from the time point at which the pulse is generated from the means to the sampling timing;
For the state equation, the four variables of motor rotation speed, position or rotation angle, motor torque, and load disturbance torque are set as state variables, and the system input is the command value of the motor torque, and the system output is the position or rotation angle. a state observation means for estimating the state variable at the time of generation of a pulse from the pulse generation means immediately before each sampling timing; and a state variable estimated by the state observation means and the time difference measurement for each sampling timing. instantaneous position calculation means for calculating an instantaneous value of the position or rotation angle of the motor at a time point further delayed by the predetermined time from the sampling timing based on the state equation from the time difference measured by the means; A method for controlling an electric motor using an instantaneous position value, characterized in that an instantaneous position value or a rotation angle value calculated by an instantaneous position calculating means is used for control calculation of the electric motor. 12. In a motor control device having a position detection means for detecting the position or rotation angle of the motor based on pulses from a pulse generation means attached to the motor, at each sampling timing, the immediately preceding pulse generation is detected. time difference measuring means for measuring the time difference from the time point at which the pulse is generated from the means to the sampling timing;
For the state equation, the four variables of motor rotation speed, position or rotation angle, motor torque, and load disturbance torque are set as state variables, and the system input is the command value of the motor torque, and the system output is the position or rotation angle. a state observation means for estimating the state variable at the time of generation of a pulse from the pulse generation means immediately before each sampling timing; and a state variable estimated by the state observation means and the time difference measurement for each sampling timing. instantaneous speed calculation means for calculating an instantaneous value of the speed of the motor at a time point further delayed by the predetermined time from the sampling timing based on the state equation from the time difference measured by the means, the instantaneous speed calculation means; A method for controlling an electric motor using an instantaneous speed value, characterized in that the instantaneous speed value calculated by the means is used for control calculation of the electric motor. 13. In a motor control device having a position detection means for detecting the position or rotational angle of the motor based on pulses from a pulse generation means attached to the motor, the pulse generation means immediately before each sampling timing is detected. time difference measuring means for measuring the time difference from the time point at which the pulse is generated from the means to the sampling timing;
For the state equation, the four variables of motor rotation speed, position or rotation angle, motor torque, and load disturbance torque are set as state variables, and the system input is the command value of the motor torque, and the system output is the position or rotation angle. a state observation means for estimating the state variable at the time of generation of a pulse from the pulse generation means immediately before each sampling timing; and a state variable estimated by the state observation means and the time difference measurement for each sampling timing. instantaneous acceleration calculation means for calculating an instantaneous value of the acceleration of the motor at a time point further delayed by the predetermined time from the sampling timing based on the state equation from the time difference measured by the means, the instantaneous acceleration calculation means; A method for controlling an electric motor using an instantaneous acceleration value, characterized in that the instantaneous acceleration value calculated by the means is used for control calculation of the electric motor. 14. In a motor control device having a position detecting means for detecting the position or rotation angle of the motor based on pulses from a pulse generating means attached to the motor, the pulse generation means immediately before each sampling timing is detected. time difference measuring means for measuring the time difference from the time point at which the pulse is generated from the means to the sampling timing;
For the state equation, the four variables of motor rotation speed, position or rotation angle, motor torque, and load disturbance torque are set as state variables, and the system input is the command value of the motor torque, and the system output is the position or rotation angle. a state observation means for estimating the state variable at the time of generation of a pulse from the pulse generation means immediately before each sampling timing; an instantaneous position calculation means according to claim 11; and an instantaneous velocity calculation means according to claim 12. or at least one of the instantaneous acceleration calculating means according to claim 13, and an instantaneous position value or rotation angle value calculated by the instantaneous position calculating means, and an instantaneous velocity calculated by the instantaneous velocity calculating means. or at least one of the instantaneous acceleration values calculated by the instantaneous acceleration calculation means is used for control calculation of the electric motor. How to control an electric motor.