JPH0787771A - Estimation apparatus of speed and position of motor - Google Patents

Abstract

PURPOSE:To identify the parameter of a motor with high accuracy while the cost of the apparatus is suppressed to be low. CONSTITUTION:The output value of a position sensor 19 is converted into a motor speed by a speed conversion part, the motor speed and an estimated speed from a motor-speed estimation part 30 are then compared by a subtraction part 28, and an estimated speed error is output. The motor-speed estimation part 30 outputs the estimated speed of a motor 1 on the basis of an applied voltage which is computed based on an output command value, of a motor current, of an amature winding resistance R as the parameter of the motor 1 and of an induced-voltage constant Ke. Then, the parameter of the motor 1 is identified on the basis of the estimated speed error which is obtained and of the feature of a speed error when the parameter of the motor 1 is changed. Thereby, the parameter of reliability can be identified. In addition, since the resolution of the position sensor 19 may be low and the applied voltage is found by a computation, it is possible to suppress a rise in the cost of the apparatus to be low.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor speed / position estimation device suitable for use in, for example, a power window device of a vehicle.

[0002]

2. Description of the Related Art For example, in a power window device, it is necessary to detect the speed and position of a motor in order to control the raising and lowering of the window. Conventionally, predetermined parameters (armature winding resistance R, induced voltage constant K _e ) Is used to estimate the speed and position of the motor. Further, conventionally, there is also a motor speed / position estimation device that obtains a parameter by calculation by the least squares method and estimates the speed and position of the motor by using the obtained parameter.

[0003]

However, the conventional motor speed / position estimation device has the following problems. In the motor speed / position estimation device that estimates the speed and position of the motor using the predetermined parameters, the parameters of the motor change due to temperature changes, aging changes, etc., and thus errors occur in the estimated speed and position. . Calculate the parameters by the method of least squares,
In the motor speed / position estimation device that estimates the speed and position of the motor using the parameters obtained by this, only the mathematical processing is performed, the physical meaning is not included in the calculation, and the calculation accuracy is There is also a problem with the measurement accuracy of the voltage and current required for calculation, and the reliability of the obtained parameters is low.

Therefore, the present invention is capable of accurately identifying motor parameters while suppressing an increase in price, thereby enabling accurate estimation of motor speed and position. Is intended to provide.

[0005]

In order to achieve the above object, a motor speed / position estimating device according to the invention of claim 1 is a motor position detecting means for detecting a position of a motor and an output given to the motor driving means. Applied voltage estimation means for calculating the voltage applied to the motor based on the command value, and the armature winding resistance and the induced voltage constant which are the parameters of the motor,
Motor speed estimating means for estimating the speed of the motor based on the motor applied voltage and the motor current, speed converting means for converting the position of the motor detected by the motor position detecting means into speed, and output from the motor speed estimating means. Comparing means for comparing the estimated speed with the motor speed output from the speed converting means to output an estimated speed error, the characteristics of the speed error at the time when each of the parameters changes, and the comparing means outputting the characteristic. Motor parameter identifying means for identifying each parameter of the motor based on the estimated speed error.

The motor speed / position estimation device according to the second aspect of the present invention is the motor speed / position estimation device according to the first aspect of the present invention, and in addition to the configuration of the motor speed / position estimation device according to the first aspect, It is characterized by having a motor speed / position estimating means for estimating the motor speed and the position based on the parameters.

The motor speed / position estimation device according to the third aspect of the present invention is the motor parameter identification means of the motor speed / position estimation device according to the first aspect of the present invention. Each of the parameters is identified based on the fact that the estimated speed error due to the armature winding resistance is proportional to the motor current.

[0008]

According to the present invention, each parameter is identified from the estimated speed error of the motor and the characteristics of the speed error in each parameter (armature winding resistance R, induced voltage constant K _e ). Then, the speed of the motor is estimated based on the identified parameters, the motor applied voltage, and the motor current, and the estimated speed is integrated to estimate the position.

Therefore, by using the relationship between the estimated speed error of the motor and the change of each parameter of the motor,
Reliable parameters can be identified. Further, when the parameters are identified by using this relationship, it is possible to estimate the speed and the position with high accuracy even with the low-resolution motor position detecting means. Moreover, since the motor applied voltage required for speed estimation is calculated based on the output command to the motor, a circuit for detecting the motor voltage becomes unnecessary.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram of an embodiment in which a motor speed / position estimation device according to the present invention is applied to a power window device.
In this figure, reference numeral 1 is a motor (DC motor), and 2 is a speed reducer, which reduces the speed of the motor 1. A support arm 3 is connected to the speed reducer 2, and the window 4 is moved up and down via the support arm 3. The motor 1, the speed reducer 2 and the support arm 3 are built in the door 5. Reference numeral 6 denotes a motor driving device, which drives the motor 1 based on the operation of a window raising / lowering operation switch (not shown).

FIG. 2 is a block diagram showing the configuration of the motor drive device 6. In this figure, 10 is a CPU (Central Processing Unit), which controls the overall control of the motor 1.
Specifically, PWM, which is the voltage operation amount that drives the motor 1.
A command value is created and supplied to the drive control circuit 11. Also,
From the characteristics of the speed error of the motor 1, the CPU 10
Is identified, and the speed and position of the motor 1 are calculated and output using this parameter. The details of parameter identification will be described later. The CPU 10 has
A read-only memory (for example, ROM) in which a command program for performing these operations is written, a work memory (for example, RAM) used in the operation, and an A / D converter for converting an analog signal into a digital signal are built-in. Has been done.

The drive control circuit 11 calculates a control value for controlling the four switching elements SW1 to SW4 by a pulse width modulation method (PWM method) according to the PWM command value and its polarity, and drives the control value with a gate. Supply to the circuit 12. The gate drive circuit 12 inputs the battery voltage boosted by the boost power supply circuit 13 based on the control value supplied from the drive control circuit 11, and drives the gates of the four switching elements SW1 to SW4 by the PWM method. The switching elements SW1 to SW4 are connected in an H-bridge type and constitute an H-bridge circuit 14 together with the four diodes D1 to D4 to control the switching of the current of the motor 1. The H bridge circuit 14 is connected to a battery 16 via a power relay 15.

The H bridge circuit 14 is PWM driven as described above. For example, in the case of normal rotation, the switching elements SW1 and SW4 are PWM driven as shown in FIG. At this time, when PWM is on, current flows through the route of battery 16 → switching element SW1 → motor 1 → switching element SW4 → shunt resistance Rs → GND, and when PWM is off, motor 1 → diode D3 → battery 16 →
GND → shunt resistance Rs → diode D2 → motor 1
The current flows through the path. Here, the drive characteristic (PWM drive characteristic) of the H bridge circuit 14 is as shown in FIG.
In the case of normal rotation, the duty ratio of the PWM command value is about 50%
When the duty ratio of the PWM command value exceeds about 50% in the case of reverse rotation, the motor current sharply decreases. In this case, when the duty ratio of the PWM command value is 0%, the all-gate off mode is set, and when the duty ratio is 50% or less, the load current intermittent mode is set. When the duty ratio is 50% or more, the load current continuous mode is set.

In FIG. 2, reference numeral 17 denotes a motor current detection circuit, which detects the motor current from the voltage across the shunt resistor RS. Then, the detection result is supplied to the CPU 10 and the overcurrent detection circuit 18. The overcurrent detection circuit 18 detects the overcurrent of the motor 1 and outputs the detection result to the CPU 1
Supply to 0. The detection result of the overcurrent detection circuit 18 is also input to the drive control circuit 11, and when the overcurrent of the motor 1 is detected, the driving of the motor 1 is prohibited. A position sensor 19 detects the position of the motor 1 and outputs it. This output is input to the CPU 10. This position sensor 19
For this, a low-resolution one is sufficient, and a low-cost one with a low resolution is preferable in the sense of reducing the price.

FIG. 5 is a block diagram functionally showing the motor drive device 6. In this figure, the current control portion 1
00 is a current command unit 21, a current deviation calculation unit 22, a PI control unit 23, an armature current detection unit 24, and a motor drive unit 25.
It consists of and. The current command unit 21 outputs a command value of the current passed through the motor 1. The current deviation calculator 22 determines the current command value and the armature current (motor current) flowing through the armature winding of the motor 1.
The deviation from I is taken and the deviation value e is output. The PI controller 23 receives the deviation value e output from the current deviation calculator 22 and outputs an output command value based on the deviation value e.
The armature current detector 24 detects the motor current I flowing through the motor 1.
Is detected and output. The motor drive unit 25 is the PI control unit 2.
A voltage based on the output command value of 3 is applied to the motor 1.

Motor speed estimation and parameter identification part 1
10 includes an applied voltage estimation unit 26, a speed conversion unit 27, a subtraction unit 28, a motor parameter identification unit 29, a motor speed estimation unit 30, and an integration unit 31. Applied voltage estimation unit 26
Calculates the voltage applied to the motor 1 based on the output command value output from the PI control unit 22, and outputs the applied voltage V. The speed conversion unit 27 differentiates the output of the position sensor 20 to convert it into a motor speed ω and outputs it. The subtraction unit 28 takes the deviation between the motor speed ω output from the speed conversion unit 27 and the calculated motor speed ω _es, and the deviation value (ω−ω _es :
Speed estimation error) is output.

The motor parameter identification unit 29 is provided in the subtraction unit 2
The deviation value (ω−ω _es ) output from 8 is input, and the armature winding resistance R, which is a parameter of the motor 1, and the induced voltage constant Ke are identified based on the deviation value (ω−ω _es ). ,Output. Here, the motor speed ω and the calculated motor speed ω
The relationship with _es is shown below. When the current is changed to I ₁ and I ₂ , ω ₁ −ω _1es −ω _R = ω ₁ − (ω ₁ / X) ω ₂ −ω _2es − (I ₁ / I ₂ ) · ω _R = ω ₂ − (Ω ₂ / X) where ω ₁ and ω ₂ are the motor speeds when the currents I ₁ and I ₂ are ω _1es and ω _2es are the calculated motor speeds when the currents I ₁ and I ₂ are X: induction of the motor. Deviation between voltage constant Ke and calculated induced voltage constant Ke ω _R : Deviation of speed due to deviation of armature winding resistance R at current I From the above, Ke = Ke _es / X R = R _es − (Ke・ Ω _R · / I ₁ ) and the parameters of the motor 1 are identified.

In FIG. 5, the motor speed estimating section 30 outputs the motor current I output from the armature current detecting section 24, the estimated applied voltage V output from the applied voltage estimating section 26, and the parameter identifying section 29. The armature winding resistance R and the induced voltage constant Ke are input, and the motor speed ω _es is calculated based on these values and output. Here, the motor speed ω is expressed as follows from the steady-state electric equation of the DC motor. ω = (V-RI) / Ke where R: motor armature winding resistance Ke: induced voltage constant

In FIG. 5, the integrator 31 determines the motor speed ω
_The motor position θ _es is obtained by integrating _es , and this is output.
In this case, the motor position θ _es is treated as position information for raising the power window (see FIG. 6). The motor speed estimation unit 30 and the integration unit 31 form a motor speed / position estimation unit 120.

Next, the details of the derivation of the parameters of the motor 1 in the motor parameter identification unit 29 will be described using equations. As described above, the armature winding resistance R and the induced voltage constant Ke, which are parameters of the motor 1, are R = R _es − (Keω _R ) / I ₁ Ke = Ke _es / x R: Armature winding resistance Ke: Induction Voltage constant R _es : Calculated R Ke _es : Calculated Ke I ₁ : Current ω _R : Velocity error due to deviation at current I ₁ x: Calculated as an error between Ke and Ke _es .

[0021] <concept> R ≠ R _es, speed error in the case of Ke = Ke _es is, R ≠ R _es, speed error in the case of Ke = Ke _es and R = R _es,
It can be approximated to the sum of velocity errors when Ke = Ke _es . When R ≠ R _es and Ke = Ke _es , the velocity error caused by the error in R is proportional to the current I. Velocity error is calculated when different currents I ₁ and I ₂ are flown,
By expressing the velocity error of R on the one hand by using the current, the unknowns are reduced and simultaneous equations are constructed.

<Derivation procedure> (I) The following is the basis for <Concept>. (II) The following shows the basis of <Concept>. (III) <Concept> is expressed by a mathematical formula and parameters are derived. <Derivation> ω ₁ , ω ₂ : Motor speed of currents I ₁ and I ₂ ω _1es , ω _2es : Calculated motor speed of currents I ₁ and I ₂ x: Ratio of motor Ke and calculated Ke _es ω _R : Deviation of speed due to deviation of R at current I ₁

(I) Relationship between R and R _es , Ke and Ke _es Velocity error (1) R ≠ R _es , Ke ≠ Ke _es ω−ω _es (2) R ≠ R _es , Ke = Ke _es ω−ω _It is shown below that _Res (3) R = R _es and Ke ≠ Ke _es ω−ω _Kes (1) ≈ (2) + (3). (1) Let ω-ω _es = ω- (VR _es I) / Ke _es R _es = yR and Ke _es = xKe. ω-ω _es = ω- (V-yRI) / xKe (2) + (3) ω-ω _Res + ω-ω _Kes = ω-((V-yRI) / Ke) + ((V-RI) / Ke)-((V-RI) / xKe) = ω-((V-yRI) / Ke) + ((xy-x-y + 1) RI / xKe) = ω-((V-yRI) / xKe ) + ((x-1) (y-1) RI / xKe)

Here, y is compared with (x-1) (y-1). 0.5 ≦
The results when x ≦ 1.5 and 0.5 ≦ y ≦ 1.5 are shown in FIG. In the alternate long and short dash line in this figure, y and (x-1) (y-1) have order 1
Since it is smaller than a digit, (x-1) (y-1) RI / xKe can be ignored. ω-ω _Res + ω-ω _Kes ≈ ω-((V-yRI) / xK _e ). That is, ω−ω _es ≈ω−ω _Res + ω−ω _Kes .

Here, the simulation results are shown in FIGS. In this case, FIG. 8 shows that R = 0.738, Ke
= 0.0167 and ± 10% when R and Ke are changed, respectively, and FIG. 9 shows R = 0.738 and Ke =
0.0167 is the result when both ± 10% R and Ke are changed. From FIG. 8 and FIG. 9, R = 0.8118, K
ω−ω _es when e = 0.01837 is R = 0.81.
18, Ke = 0.167 and R = 0.738, Ke = 0.
It becomes substantially equal to the value obtained by adding ω-ω _es in 01837. The value within the alternate long and short dash line in FIG. 7 rarely changes to ± 50% or more, but if necessary, a function for checking whether or not the calculation result is within the alternate long and short dash line may be provided. Good.

(II) When R ≠ R _es and K _e = Ke _es , ω-ω _es = (V-RI) / K _e- (VR _es I) / K _e = (R _es -R) I / K _{e namely, R ≠ R es, ω-} ω es when Ke = Ke _es is proportional to the current I. Here, a simulation result is shown in FIG. As shown in this figure, it can be seen that ω−ω _es (= Δω) is proportional to the current I.

[0027] _{(III) R ≠ R es,} ω-ω es = (V-RI) when _{Ke ≠ Ke es / Ke- (VR} es I) / Ke es here, and Ke = Ke _es / x. ω-ω _es = (1-1 / x) ω… (1) From the result of (I) ω-ω _es = ω-ω _Res + ω-ω _Kes where, ω-ω _Res = ω _R ω-ω _{Set Kes} = ω _K. ω-ω _es = ω _R + ω _K ω-ω _es -ω _R = ω _K ... (2) From equations (1) and (2), ω-ω _es -ω _R = (1-1 / x) ω (3) From the results of Eq. (3) and (II), ω ₁ -ω _1es -ω _R = (1-1 / x) ω ₁ (when the current is I ₁ ) ω ₂ -ω _2es -I ₂ ω ₂ / I ₁ = (1-1 / x) ω ₂ (when the current is I ₂ ) holds. Solving _{this, R = R es - (Keω} R / I 1) Ke = Ke es / x is derived. In this way, the parameter is identified based on the characteristic of the speed error when the parameter changes and the estimated speed error ω−ω _es output from the subtraction unit 28. Motor speed and position are estimated based on the identified parameters.

Although the above embodiment is applied to the power window device, it may be applied to other devices such as an electrically driven antenna, a sunroof, a moonroof and a power seat, which move a specific portion by a motor. Of course, it can be applied. In addition, the invention can be applied not only to an on-vehicle device but also to an electric drive device.

[0029]

According to the present invention, the estimated speed error of the motor and each parameter (armature winding resistance R, induced voltage constant K
_Since each parameter is identified based on the characteristics of the velocity error when _e ) changes, a highly reliable parameter can be identified. Further, by calculating the speed and position of the motor using the identified parameters, the speed and position can be estimated with high accuracy even by the low-resolution motor position detecting means (position sensor 19), and the cost can be reduced. Can be achieved. Also,
Since the motor applied voltage required for speed estimation is calculated based on the output command to the motor, a circuit for detecting the motor voltage is not required, and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a power window device to which a motor speed / position estimation device according to an embodiment of the present invention is applied.

FIG. 2 is a block diagram of the power window device according to the embodiment.

FIG. 3 is a diagram for explaining motor driving of the power window device according to the embodiment.

FIG. 4 is a drive characteristic diagram of the power window device according to the embodiment.

FIG. 5 is a functional block diagram of the power window device according to the embodiment.

FIG. 6 is a diagram for explaining an output result of the power window device according to the embodiment.

FIG. 7 is a diagram for explaining derivation of parameters of the power window device according to the embodiment.

FIG. 8 is a diagram for explaining derivation of parameters of the power window device according to the embodiment.

FIG. 9 is a diagram for explaining derivation of parameters of the power window device according to the embodiment.

FIG. 10 is a diagram for explaining derivation of parameters of the power window device according to the embodiment.

[Explanation of symbols]

19 Position Sensor (Motor Position Detection Means) 26 Applied Voltage Estimator (Applied Voltage Estimator) 27 Speed Converter (Speed Converter) 28 Subtractor (Comparison Means) 29 Motor Parameter Identification (Motor Parameter Identification Means) 30 Motor Speed Estimating unit (motor speed estimating means) 120 Motor speed / position estimating means

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Claims (3)

[Claims] 1. A motor position detecting means for detecting a position of a motor, an applied voltage estimating means for calculating a voltage applied to the motor based on an output command value given to the motor driving means, and an armature which is a parameter of the motor. A motor speed estimating means for estimating a motor speed based on a winding resistance and an induced voltage constant, a motor applied voltage and a motor current; and a speed converting means for converting a motor position detected by the motor position detecting means into a speed. Comparing means for comparing the estimated speed output from the motor speed estimating means with the motor speed output from the speed converting means to output an estimated speed error, and comparing the speed error of each of the parameters when the parameters change. A motor parameter for identifying each parameter of the motor based on the characteristics and the estimated speed error output from the comparison means. Motor speed and position estimation device characterized by comprising: a data identification means. 2. The motor speed / position estimation means according to claim 1, further comprising a motor speed / position estimation means for estimating a motor speed and position based on each of the parameters identified by said motor parameter identification means. apparatus. 3. The motor parameter identifying means identifies each of the parameters based on an estimated speed error due to the armature winding resistance of the motor being proportional to the motor current. 2. The motor speed / position estimation device according to any one of items.