JP3332226B2 - Actuator device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actuator device, and is suitably applied to, for example, an AC (Alternating Current) servomotor.

[0002]

2. Description of the Related Art Conventionally, in an AC servomotor, a rotatably supported rotor, a plurality of stator cores fixedly disposed at predetermined intervals so as to surround the rotor, and each stator core are wound around the rotor. And a stator comprising a plurality of coils are integrally housed inside the motor case.

In an AC servomotor, usually,
A rotation position sensor for detecting a rotation position of the rotor shaft is provided on a non-rotation torque output side of a rotor shaft (hereinafter, referred to as a rotor shaft) outside the motor case.

In an actuator system using such an AC servomotor, a controller is provided separately from the AC servomotor, and the controller uses a sensor signal output from a rotation position sensor of the AC servomotor. Various arithmetic processes for obtaining a desired rotation output are executed, and the rotation of the AC servomotor is controlled by supplying a drive current based on the calculation result from the controller to the AC servomotor.

[0005]

However, in such an actuator system, a total of three cables for rotation drive (for coils) and four to twelve cables for rotation position sensors are used as cables connecting the controller and the AC servomotor. 7
There is a problem that 15 to 15 relatively thick wires are required, and special wires having special cable specifications that take into account the effects of noise and the like and disconnection due to mechanical vibration are required.

In such an actuator system, in addition to the wiring between the AC servomotor and the controller, a communication wiring between the controller and a higher-level controller is required. However, there is a problem in that the configuration is complicated and the assemblability is poor because of the large number of components.

Further, in such an actuator system, since the rotor of the AC servomotor and the rotational position sensor are structurally arranged at distant positions, an AC servomotor is required to perform high-precision and high-speed positioning. Since the rotor shaft of the motor is required to be thick and a structural member of the connecting portion is required to have high mechanical rigidity, there is a problem that the whole system becomes heavy and large.

Further, in such an actuator system, since the rotational position sensor is large and heavy, a large AC servomotor is required to perform high-speed positioning, and the bearing has a high rigidity. There was a problem that required something.

Further, in such an actuator system, since the AC servomotor generates heat when driven, the maximum value of the drive current given to the AC servomotor is limited. However, there is a problem that the output torque is limited because only a low current including the above can be supplied to the AC servomotor.

The present invention has been made in view of the above points, and an object of the present invention is to propose an actuator device which can simplify the structure of an actuator system and can be easily reduced in size while improving performance.

[0011]

According to the present invention, there is provided an actuator device in which a rotor and a stator are housed in a single space defined by a housing, and detects a rotation angle of the rotor. The rotation angle detection means and a calculation means for determining a current command value to be given to the drive circuit based on the detection result of the rotation angle detection means are provided in the space. As a result, in this actuator device, the amount of wiring between itself and the outside can be significantly reduced.

Further, according to the present invention, in an actuator device in which a rotor and a stator are accommodated in one space formed by a housing, a rotation angle detecting means for detecting a rotation angle of the rotor, and a detection result of the detecting means. Computing means for determining a current command value to be given to the drive circuit based on the above is provided in the space, and the rotation angle detecting means and the computing means are mounted on the same substrate. As a result, in this actuator device, the amount of wiring between itself and the outside can be significantly reduced.

Further, according to the present invention, in an actuator device in which a rotor and a stator are housed in one space defined by a housing, a drive circuit for supplying a drive current to the stator and a rotation angle of the rotor are detected. Rotation angle detection means, temperature detection means for detecting the temperature of the driving permanent magnet constituting the rotor, and calculation for determining a current command value to be given to the drive circuit based on the detection results of the rotation angle detection means and the temperature detection means Means are provided in the space, and the rotation angle detecting means, the temperature detecting means and the calculating means are mounted on the same substrate. As a result, in this actuator device, the arithmetic means can easily detect the upper limit of the current command value given to the drive circuit based on the detection result of the temperature detection means while significantly reducing the amount of wiring to the outside. it can.

Further, in the present invention, in the actuator device, control means for controlling the rotation of the rotor and communication means for performing serial communication with the outside by the control means are provided in the housing. As a result, in this actuator device, the amount of wiring can be remarkably reduced as compared with the case where such communication means is provided outside the housing.

[0015]

[0016]

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

(1) Configuration of AC Servo Motor According to the Present Embodiment In FIG.
It shows a servomotor, and includes a motor unit 2 that generates a rotational torque, and a torque amplifying unit 3 that amplifies and outputs the rotational torque generated in the motor unit 2.

In the motor section 2, a rotor shaft 6 rotatably supported by rotating bearings 5A and 5B is provided inside a motor case 4 made of a conductive material such as metal, and the rotor shaft 6 is attached to a rotor base 7 As shown in FIGS. 2B and 2C, a rotor 9 is formed by coaxially integrating a rotor magnet 8 composed of a ring-shaped permanent magnet magnetized into four poles.

As shown in FIGS. 3 and 4 (A), the inside of the motor case 4
The stator cores 10A to 10F are fixed at equal intervals (at an interval of 60 °), and each of the stator cores 10A to 10F is fixed.
The coils 11 (11A to 11F) are formed by applying windings to (10A to 10F), respectively.

As a result, in the motor section 2, 180
[°] Two coils 11 (11A and 11D,
11B and 11E, 11C and 11F) (there are three sets in total) as U-phase, V-phase and W-phase, respectively.
120 ° for each of the phase 11, V and W phase coils 11
By applying a drive current having a phase shifted by each step to generate a magnetic field having a strength corresponding to the current value of the drive current in each coil 11, a rotation torque having a magnitude corresponding to the current value of the drive current is passed through the rotor 9. Has been made to be able to generate.

On the other hand, as shown in FIGS. 1 and 5A to 5C, the torque amplifying section 3 has a gear case 12 which is detachably fixed to the tip of the motor case 4.
Inside the gear case 12, an annular internal gear 13 fixed to the inner surface of the gear case 12, a sun gear 14 fixed to the tip of the rotor shaft 6, and an internal gear 13
And the first gears disposed at intervals of 120 ° between the sun gear 14 and
To a third planetary gear set 15A to 15C.

Each of the shafts 17A to 17C of the first to third planetary gears 15A to 15C of the planetary gear mechanism 16 is an output shaft 1 rotatably disposed at the tip of the gear case 12.
8 is fixed.

Thus, the torque amplifying section 3 amplifies the rotational torque given from the motor section 2 via the rotor shaft 6 via the planetary gear mechanism 16 and amplifies the rotational torque.
8 and output to the outside via the output shaft 18.

The torque amplifying section 3 has an annular resin magnet 19 fixed to the output shaft 18 and first and second resin magnets 19 fixed to the outer peripheral surface of the gear case 12 so as to face the outer peripheral surface of the resin magnet 19. A one-turn absolute angle sensor 21 including second magnetic sensors (hereinafter, referred to as Hall elements) 20A and 20B is provided.

In this case, the resin magnet 19 is
As shown in (A), the magnetic flux density φ (θ
g) is magnetized so as to change as shown in FIG.
The first and second Hall elements 20A and 20B are shown in FIG.
Gear case 1 with a phase difference of 90 ° as shown in FIG.
2 is fixed to the outer peripheral surface.

Thus, in the one-rotation absolute angle sensor 21, the rotational displacement of the output shaft 18 is changed by the magnetic flux density φ () at the position where the first and second Hall elements 20A and 20B are provided with the rotation of the output shaft 18. θg) as a change and the detection result is referred to as the first and second Hall elements 20A, 20A.
B to sin (θ) as shown in FIG.
g) and cos (θg) can be output as first and second one-turn absolute angle sensor signals S1A and S1B having waveforms given by cos (θg).

In addition to this configuration, the AC servomotor 1
, A rotor shaft magnetic pole angle sensor 2 for detecting the magnetic pole angle of the rotor shaft 6 is provided inside the motor case 4 of the motor unit 2.
2, a control board 23 for controlling a rotation angle, a rotation speed, a rotation torque, and the like of the output shaft 6 based on a command from an external host controller (not shown), and a motor unit under the control of the control board 23. And a power board 24 for supplying a drive current to each of the second coils 11.

In this case, the rotor shaft magnetic pole angle sensor 22
A resin magnet 25 fixed to the front end face of the rotor base 7 of the rotor 9 and first to fourth magnetic sensors (hereinafter, referred to as Hall elements) 26A to 26D mounted on the control board 23
And is formed from And the resin magnet 25
As shown in FIGS. 2B and 2C, the rotor 9 is magnetized to the same four poles as the rotor magnet 8, and is fixed to the rotor base 7 in the same phase as the rotor magnet 8.

The first to fourth Hall elements 26A to 26A
8D, the first and second Hall elements 26A and 26B are 180 ° concentric with the rotor shaft 6 as shown in FIG.
[°] opposing and the third and fourth Hall elements 26C,
26D are the first and second Hall elements 26A, 26
It is mounted on the control board 23 so as to be located at a position shifted by 45 ° in the same direction as B.

Thus, the rotor shaft rotation angle sensor 2
2, the magnetic pole angle of the rotor shaft 6 is detected as a change in the magnetic flux density at the position where the first to fourth Hall elements 26A to 26D are arranged due to the rotation of the resin magnet 25 that rotates integrally with the roller shaft 6. It is made to be able to do.

Note that the magnetic pole angle of the rotor shaft 6 is defined as an angle obtained by multiplying the mechanical rotation angle of the rotor shaft 6 by a value half the number of magnetic poles of the rotor magnet 8 (see the equation (2)). In this embodiment, since the rotor magnet 8 is magnetized to four poles, the magnetic angle takes a value in a range from 0 to 2π.

On the other hand, the control board 23 is shown in FIGS.
As shown in FIGS. 8 and 9, a one-chip microcomputer 27 and a crystal oscillator 28 for clock generation are mounted on one surface of a printed wiring board formed in an annular shape, and the above-described rotor shaft rotation is mounted on the other surface. First of angle sensor 22
To the fourth Hall elements 26A to 26D and a temperature sensor 29 for detecting the temperature of the resin magnet 25.

In this control board 23, FIG.
The output of the first and second Hall elements 26A and 26B and the output of the third and fourth Hall elements 26C and 26D in the rotor shaft magnetic pole angle sensor 22
And the second and third rotor shaft magnetic pole angle sensor signals S2A and S2.
B is taken into the one-chip microcomputer 27 and the one-turn absolute angle sensor 21 (FIGS. 1 and 5).
(C)) and the first and second one-turn absolute angle sensor signals S1A, S1 supplied via the cable 31 (FIG. 1).
B can be taken into the one-chip microcomputer 27.

In the control board 23, two power supply lines, one general-purpose parallel communication line, and two RS
232C serial communication line and three synchronous serial communication lines are connected to the host controller through a second cable 32 (FIG. 1), and thus the one-chip microcomputer 27 is connected to the second cable 3
2, a driving voltage can be input and communication with a higher-level controller can be performed.

Then, the one-chip microcomputer 27
Is a designated value of the rotation angle, the rotation speed, or the rotation torque of the output shaft 18 (FIG. 1) provided from the host controller via the second cable 32 (hereinafter, these are designated rotation angle, designated rotation speed, and designated (It is called rotation torque)
And the first and second one-turn absolute angle sensor signals S1A,
S1B, first and second rotor shaft magnetic pole angle sensor signals S2A and S2B, and first to third drive current detection signals S3A to S3C supplied from the power board 24 as described later.
, The current values of the drive currents to be applied to the U-phase, V-phase and W-phase coils 11 (hereinafter referred to as first to third current command values, respectively) are calculated. The calculated first to third current command values are transferred to the third cable 3
3 to the power board 24.

In the power board 24, FIGS.
As shown in (B) and (C), a plurality of power transistor chips 35 forming a coil drive block 34 shown in FIG. 10 are mounted on one surface of a printed wiring board formed in an annular shape. I have.

Based on the first to third current command values supplied from the one-chip microcomputer 27 of the control board 23, the coil drive block 34 controls the U-phase, V-phase and W-phase of the motor unit 2. A driving current having a corresponding current value is applied to the coil 11 to rotate the rotor 9 of the motor unit 2.

At this time, the coil driving block 34 detects the current values of the driving currents applied to the U-phase, V-phase and W-phase coils 11 at this time, and outputs the detection results to the first to third coils. The control board 23 via the third cable 33 (FIG. 1) as the drive current detection signals S3A to S3C for
To send to.

In this way, in the AC servomotor 1, the one-chip microcomputer 27 of the control board 23
The motor unit 2 is driven in accordance with a specified rotation angle, a specified rotation speed, or a specified rotation torque given by a host controller by a control circuit including a coil drive block 34 of the power board 24.

(2) One-chip microcomputer 27
As shown in FIG. 11, the one-chip microcomputer 27 includes an arithmetic processing block 40, a register 41, a rotor shaft rotation angle detection processing block 42, and a torque-three-phase current signal conversion processing block 43, as shown in FIG. , Current control processing block 4
Fourth and first to fourth analog / digital conversion circuits 45
~ 48.

Then, the one-chip microcomputer 27
Then, one-turn absolute angle sensor 21 (FIG. 1, FIG. 5 (C))
The first and second one-turn absolute angle sensor data D1A obtained by digitally converting the first and second one-turn absolute angle sensor signals S1A and S1B supplied from the third analog / digital conversion circuit 47. , D1B in the register 41.

In the one-chip microcomputer 27, the first and second rotor shaft magnetic pole angle sensors based on the output of the rotor shaft magnetic pole angle sensor 22 given from the first and second subtraction circuits 30A and 30B (FIG. 9). Signal S2A,
S2B is digitally converted in a second analog / digital conversion circuit 46, and the obtained first and second rotor shaft magnetic pole angle sensor data D2A and D2B are input to a rotor shaft rotation angle detection processing block 42.

Rotor shaft rotation angle detection processing block 42
Is based on the supplied first and second rotor shaft magnetic pole angle sensor data D2A and D2B, and the magnetic pole rotation angle of the rotor shaft 6 (hereinafter referred to as the rotor shaft magnetic pole rotation angle) Pml
And the magnetic pole angle θp are detected, the rotor shaft rotation angle Pml is stored in the register 41, and the magnetic pole angle θp is determined by the torque −
The signal is sent to the three-phase current signal conversion processing block 43.

Note that the magnetic pole rotation angle of the rotor shaft 6 (rotor shaft magnetic pole rotation angle Pml) is the first
The angle is defined as one cycle (0 to 2π) in which the magnetic pole change by a pair of adjacent N and S poles of the resin magnet 25 detected by the fourth Hall elements 26A to 26D is one cycle.
In this embodiment, since the resin magnet 25 is magnetized to four poles, the rotor shaft magnetic pole rotation angle Pml takes a value in the range of 0 to 4π.

Then, the arithmetic processing block 40 specifies the first and second one-turn absolute angle sensor data D1A and D1B and the rotor shaft magnetic pole rotation angle Pml stored in the register 41 in this way, and the designation given from the host controller. A target rotation torque (hereinafter referred to as a target rotation torque) T0 is calculated based on the rotation angle, the specified rotation speed or the specified rotation torque, and the calculation result is stored in the register 41.

The target torque T0 stored in the register 41 is read out by the torque / three-phase current signal conversion processing block 43. The torque-three-phase current signal conversion processing block 43 outputs the target torque T0 and the rotor shaft 6 given from the rotor shaft rotation angle detection processing block 42.
Of the motor unit 2 based on the magnetic pole angle θp of
The above-described first to third current command values U representing the current values of the drive currents to be applied to the respective coils 11 of the phase, V phase and W phase
r, Vr, and Wr are calculated and sent to the current control processing block 44.

At this time, the current control processing block 44 converts the first to third drive current detection signals S3A to S3C supplied from the power board 24 from the first analog / digital conversion circuit 45 into digital signals. The obtained first to third drive current detection data D3A, D3B
Is given.

Thus, the current control processing block 44 determines the first to third current command values Ur, Vr, Wr and the first
Based on the third drive current detection data D3A, D3B, the first to third current command values Ur, Vr, Wr are subjected to predetermined signal processing including compensation processing for voltage fluctuations, and PWM (Pulse Width Modulation) modulation,
The obtained first to third PWM signals S4A to S4C are converted to third signals.
This is sent to the coil drive block 34 of the power board 24 via the cable 33 of FIG.

Note that the third cable 33 has first to third
Are provided for the PWM signals S4A to S4C. And the current control processing block 44
When the output shaft 18 (FIG. 1) is driven forward,
Each of the third PWM signals S4A to S4C is connected to one of the first PWM signals S4A to S4C.
, And to the coil drive block 34 of the power board 24, and the first to third PWM signals S4A
To S4C (hereinafter, referred to as first to third reference signals) S5A to S5C are applied to the coil drive block 34 of the power board 24 via the other second lines, respectively. Send out.

When the output shaft 18 is driven to rotate in the reverse direction, the current control processing block 44 controls the first to third PWM signals S
4A to 4C are respectively sent to the coil drive block 34 of the power board 24 via the second line, and the first to third reference signals S5A to S5C are respectively sent to the power board 24 via the first line. Coil drive block 3
4

In the coil drive block 34, FIG.
As shown in FIG. 0, four amplifiers 50A to 50A correspond to the U-phase, V-phase, and W-phase coils 11, respectively.
C, first to third gate drive circuits 51A to 51C having the same configuration, two PNP transistors TR1, TR2 and two NPN transistors TR, respectively.
3 and TR4, and comprises first to third inverter circuits 52A to 52C of the same configuration.

In the coil driving block 34,
U-phase, V-phase and W-phase first lines correspond to the first to third amplifiers 50A and 50C of the corresponding first to third gate drive circuits 51A to 51C, respectively. The base of the second PNP transistor TR2 of the third inverter circuits 52A to 52C and the first N
Connected to the base of the PN transistor TR3,
Each of the V-phase and W-phase second lines corresponds to the first
To the third gate drive circuits 52A to 52C via the second and fourth amplifiers 50B and 50D, respectively, corresponding to the second P of the first to third inverter circuits 52A to 52C.
The base is connected to the base of the NP transistor TR2 and the base of the first NPN transistor TR4.

In the coil drive block 34, the U-phase, V-phase and W-phase coils 11 of the motor section 2 correspond to the first to third inverter circuits 52A to 52C, respectively.
, The connection midpoint between the collector of the first PNP transistor TR1 and the collector of the first NPN transistor TR3, and the connection midpoint between the collector of the second PNP transistor TR2 and the collector of the second NPN transistor TR4. Connected between

As a result, in the coil drive block 34, the first to third PWM signals S4A to S4C provided via the first or second line for each of the U, V and W phases. Are converted into analog waveform drive currents Iu, Iv, Iw in the corresponding first to third inverter circuits 52A to 52C, and these are applied to the corresponding U-phase, V-phase, and W-phase coils 11, respectively. It has been made possible.

In the coil drive block 34,
The magnitudes of the drive currents Iu, Iv, and Iw supplied to the U-phase, V-phase, and W-phase coils 11 are detected by current sensors 53 including coils provided in the first to third inverter circuits 52A to 52C. Then, the detection results are converted to the first to third first to third drive current detection signals S3A to S3A as described above.
The data is sent to the first analog / digital conversion circuit 45 (FIG. 11) of the one-chip microcomputer 27 of the control board 23 as 3C.

(3) One-chip microcomputer 27
Here, the arithmetic processing block 40 of the one-chip microcomputer 27, the rotor shaft rotation angle detection processing block 4
The configurations of the 2, torque-three-phase current signal conversion processing block 43 and the current control processing block 44 will be described in detail.

(3-1) Detailed Configuration of Arithmetic Processing Block First, as apparent from FIG. 11, the arithmetic processing block 40 includes a CPU (Central Processing Unit) 60 and a ROM (Read Only Memory) storing various programs. )
61 and a RAM (Ra
ndom Access Memory) 62, a parallel communication input / output circuit 63 corresponding to general-purpose parallel communication, a serial communication input / output circuit 64 serving as an input / output interface circuit between the host controller, and a 1
A counter timer control circuit 65 for generating a servo interrupt signal S10 having a [ms] cycle and a PWM pulse signal S11 having a PWM cycle of 50 [μm], and a servo interrupt signal S from the counter timer control circuit 65.
A watchdog signal generating circuit 66 for generating a watchdog signal S12 which is a reference signal having a predetermined cycle of 1 [ms] cycle or longer for the CPU 60 to determine whether or not the clock signal 10 is correctly generated is mutually connected via a CPU bus 67. It is constituted by being connected to.

In this case, when the power supply voltage (5 [V]) is supplied from the host controller via the serial communication input / output circuit 64, the CPU 60 first executes the parallel communication based on the initial program stored in the ROM 61. I / O circuit 63, I / O circuit 64 for serial communication, counter
The timer / control circuit 65, the rotor shaft rotation angle detection processing block 42, the torque / three-phase current signal conversion processing block 43, and the current control processing block 44 execute start-up processing such as setting processing of various initial values and parameters.

As described above, the CPU 60 determines the target rotational torque T based on the servo interrupt signal S10 given from the counter / timer control circuit 65 and the corresponding program stored in the ROM 61 as described above.
The motor rotation control calculation processing for generating 0, the phase advance control processing, the temperature compensation control processing, and the serial communication control processing are performed as one.
Execute in time division within [ms]. The processing of the CPU 60 in each of these processing modes will be described later.

Here, the configuration of the serial communication input / output circuit 64 will be described. This serial communication input / output circuit 6
4 is configured to be compatible with both the RS-232C serial communication system and the synchronous serial communication system.

In practice, the serial communication input / output circuit 64
For example, during communication using the RS-232C serial communication method, communication is performed by transmitting and receiving a TXD signal as a transmission signal and an RXD signal as a reception signal using two lines. At this time, the data transfer rate is 9600 [bits /
[Sec], the transfer data length is 8 bits, 1 stop bit and 1 start bit, and communication with the host controller is performed in a transfer format by a data structure without a parity bit.

The serial communication input / output circuit 64 transmits and receives a TXD signal as a transmission signal, an RXD signal as a reception signal, and a synchronization clock signal using three lines during communication in the synchronous serial communication system. Communication is performed by the At this time, the data transfer speed is 800 or 1500
[Kbit / sec], communication with the controller is performed in a transfer format with a data structure of 2 bytes of synchronous character data and a transfer data length of 1 byte (8 bits) to several tens of bytes.

In this communication method, a command can be given in real time because data communication can be performed at high speed. When transferring N-byte data, the data structure of one frame is represented by “synchronous character 1 + synchronous character 2 + data 1 (8 bits) + data 2 (8 bits) +.
.. + Data N (8 bits) + synchronous character 1 + synchronous character 2 ”.

(3-2) Detailed Configuration of Rotor Shaft Rotation Angle Detection Processing Block 42 Next, the configuration of the rotor shaft rotation angle detection processing block 42 will be described in detail. As a premise, the configuration of the rotor shaft magnetic pole angle sensor 22 (FIG. 1) will be described first.

First, in the rotor shaft magnetic pole angle sensor 22, the resin magnet 25 is magnetized to the same polarity as the rotor magnet 8, and is fixed to the rotor base 7 in the same phase as the rotor magnet 8. The magnetization pattern of the resin magnet 25 has a maximum magnetic flux density of φ0 and a magnetic flux density φ (θp) of FIG.

[0067]

(Equation 1)

Is selected so that

Here, θp is the magnetic flux angle of the rotor shaft 6. The relationship between the magnetic pole angle θp and the mechanical rotation angle θm of the rotor shaft 6 is represented by the following equation, where the number of magnetic poles is P (4 in the present embodiment).

[0070]

(Equation 2)

Can be expressed as

On the other hand, the first to third rotor shaft magnetic pole angle sensors 22
The fourth Hall elements 26A to 26D face the resin magnet 25 as described above with reference to FIG.

[0073]

(Equation 3)

[0074]

(Equation 4)

[0075]

(Equation 5)

[0076]

(Equation 6)

Is mounted on the control board 23 so as to be located at the position given by

In the expressions (3) to (6), θ0 indicates a coordinate position with the position of one coil 11 as an origin.
In the following, the pole center position of one U-phase coil 11A is assumed to be θ0 = 0 (see FIG. 4A). Further, the coordinate position θ0 is given by

[0079]

(Equation 7)

The coils 11B and 11 adjacent to
Let F be the V phase and the coordinate position θ0 be

[0081]

(Equation 8)

The coils 11F and 11C given by are set to the W phase. The coils 11A and 18 whose pole center positions are θ0 = 0
0 [°] The opposing coil 11D becomes U-phase.

The number of poles Ps of the stator core 10 (FIG. 3)
(4 in the present embodiment) and the resin magnet 25
Is related to the number of magnetic poles P by the following equation:

[0084]

(Equation 9)

Is given by

Then, the first to fourth elements arranged as described above
Output Sh1, Sh2, Sh3 of the Hall elements 26A to 26D of
Sh4 is expressed by the following equation, where G0 is the sensor sensitivity coefficient of the first to fourth elements 26A to 26D, and θm is the rotation angle of the rotor shaft 6.

[0087]

(Equation 10)

[0088]

[Equation 11]

[0089]

(Equation 12)

[0090]

(Equation 13)

Is as follows. Therefore, when the rotor shaft 6 makes one rotation, the signal levels of the outputs Sh1, Sh2, Sh3, Sh4 of the first to fourth Hall elements 26A to 26D change in proportion to the magnetic pole number P of the resin magnet 25.

However, in practice, the rotor shaft 6
And an error in the squareness of the first to fourth Hall elements 26A to 26D with the sensor surfaces or an error in the concentricity, these errors are respectively represented by φe1, φe2, θe1, θe2.
The actual outputs Sh1 ', Sh2', Sh3 ', Sh4' of the first to fourth Hall elements 26A to 26D are respectively expressed by the following equations.

[0093]

[Equation 14]

[0094]

(Equation 15)

[0095]

(Equation 16)

[0096]

[Equation 17]

## EQU10 ##

The first sensor signal Sh12 (in this embodiment, the first rotor shown in FIG. 9) obtained by adding the actual outputs Sh1 'and Sh2' of the first and second Hall elements 26A and 26B. (Corresponds to the shaft magnetic pole angle sensor signal S2A)
And a second sensor signal Sh34 obtained by adding the outputs Sh3 'and Sh4' of the third and fourth Hall elements 26C and 26D (in the present embodiment, the second rotor shaft magnetic pole angle sensor signal shown in FIG. 9). S2B), assuming that θe1 and θe2 are sufficiently small, respectively

[0099]

(Equation 18)

[0100]

[Equation 19]

It can be expressed as FIG. 13 shows the waveforms of the first and second sensor signals Sh12 and Sh34.

The first and second sensor signals S
Based on h12 and Sh34, the rotor shaft 6
And the rotor shaft magnetic pole rotation speed Pml can be obtained.

That is, first, the magnetic pole angle calculation value θx is set by setting the initial value to 0, and the following equation is obtained.

[0104]

(Equation 20)

Is calculated.

If Eθx = 0 does not hold, θ
x is

[0107]

(Equation 21)

Is calculated. Here, Krp1 indicates a proportional gain and Kri1 indicates an integral gain, both of which are positive constants.

Using the calculated θx, the equation (20) is calculated again, and thereafter, this is repeated until Eθx = 0. As a result, Eθx converges to a zero value. At this time, θx becomes

[0110]

(Equation 22)

This corresponds to the rotor shaft magnetic pole rotation angle Pml.

When the rotor shaft magnetic pole rotation angle Pml is obtained in this manner, the following equation is obtained between the rotor shaft magnetic pole rotation angle Pml and the magnetic pole angle θp.

[0113]

(Equation 23)

From the relationship, the magnetic pole angle θp can be obtained based on the rotor shaft magnetic pole rotation angle Pml. In the formula (23), Nx represents an integer of 0 or more.

Based on this principle, the rotor shaft rotation angle detection processing block 42 is configured as shown in FIG. And this rotor shaft rotation angle detection processing block 4
2, the first and second rotor shaft magnetic pole angle sensor data D2A and D2B provided from the rotor shaft magnetic pole angle sensor 22 via the second analog / digital conversion circuit 46.
Is input to the arithmetic unit 70.

At this time, the arithmetic unit 70 has the magnetic pole angle arithmetic value θx previously calculated from the function converter 71 as described later.
Sine value (sin θx) and cosine value (cos θx) are given.

Thus, the computing unit 70 obtains the equation (20) based on the first and second rotor shaft magnetic pole angle sensor data D2A and D2B and the sine value and cosine value of the magnetic pole angle calculation value θx calculated in advance. Is calculated, the error between the magnetic pole angle θp given by the equation (2) and θx at that time is calculated, and the calculation result is sent to the first multiplier 72.

The multiplication result is then added to the first multiplier 72 by the following equation.

[0119]

(Equation 24)

(Where S is a Laplace operator) is multiplied by an integral gain, multiplied by a proportional gain Krp1 in a second multiplier 73, and 1 / S
(S is a Laplace operator).

As a result, the calculated magnetic pole angle θ
x is output and sent to the function converter 71 and is also applied to the magnetic pole angle calculator 75. Thus, the magnetic pole angle calculator 75 sets the value of the calculated magnetic pole angle θx at this time as the rotor shaft magnetic pole angle Pml in the register 41 (FIG. 11).
To be stored.

At this time, the magnetic pole angle calculator 75 calculates the value of θp in the range from 0 to 2π while increasing the value of Nx in equation (23) in order from 0, and calculates the magnetic angle θp To the torque-three-phase current signal conversion processing block 43.

In this manner, the rotor shaft rotation angle detection processing block 42 detects the magnetic pole angle θp and the rotor shaft magnetic pole rotation angle Pml based on the first and second rotor shaft magnetic pole angle sensor data D2A and D2B.

The rotor shaft rotation angle detection processing block 4
In 2, the arithmetic processing of the magnetic angle θp and the rotor shaft magnetic pole rotation angle Pm1 is performed based on the PWM pulse signal S11 given from the counter / timer control circuit 65 of the arithmetic processing block 40.

Therefore, the magnetic angle θp and the rotor shaft magnetic pole rotation angle Pm1 output from the rotor shaft rotation angle detection processing block 42 are the cycle of the PWM pulse signal S11.
Updated every 50 [μs].

(3-3) Detailed Configuration of Torque-Three-Phase Current Signal Conversion Processing Block 43
As shown in FIG. 11, the target rotation torque T0 stored in the register 41 (FIG. 11) is changed to a PWM pulse cycle (50 [μs
] Period, and based on the target rotation torque T0 and the magnetic pole angle θp given from the rotor shaft rotation angle detection processing block 42 (FIG. 14),

[0127]

(Equation 25)

[0128]

(Equation 26)

[0129]

[Equation 27]

By calculating the above, first to third current command values Ur, Vr and Wr are calculated and sent to the current control processing block 44 (FIG. 11).

The first to third current command values Ur, V
The arithmetic processing of r and Wr is performed by the P,
This is performed based on the WM pulse signal S11. Therefore, these first to third current command values Ur, Vr and Wr are also PWM.
It is updated every 50 [μs] which is the cycle of the pulse signal S11.

(3-4) Detailed Configuration of Current Control Processing Block 44 On the other hand, as shown in FIG. 16, the current control processing block 44 has a U-phase, a V-phase, and a W-phase coils 11 respectively. First to third signal processing systems 84A including subtraction circuits 80A to 80C, first and second multiplication circuits 81A to 81C, 82A to 82C, and PWM converters 83A to 83C.
To 84C.

In the current control processing block 44, in the first to third signal processing systems 84A to 84C, the first to third signals supplied from the torque / three-phase current signal conversion processing block 43 (FIG. 15). Current command value Ur, V
r, Wr, and the first to third signals given from the power board 24.
Based on the drive current detection signals S3A to S3C, the first to third PWM signals S4A to S4C and the first to third reference signals S5A to S3C are subjected to predetermined signal processing including voltage fluctuation compensation processing. S5C can be generated.

Actually, the first to third signal processing systems 84A to 84A
In 4C, the difference between the supplied first to third current command values Ur, Vr and Wr and the first to third drive current detection signals S3A to S3C is subtracted by subtraction circuits 80A to 80C.
C, and outputs the detection results to the first multiplication circuits 81A to 81A.
Send to 81C.

The first to third signal processing systems 84A to 84A-8
4C, to converge this error to 0, the first multiplication circuits 81A to 81C set the Laplace operator to S, and

[0136]

[Equation 28]

The multiplication result is multiplied by the proportional gain Krp in the second multiplication circuits 82A to 82C.

Then, the following equations obtained in this manner are obtained.

[0139]

(Equation 29)

[0140]

[Equation 30]

[0141]

(Equation 31)

Each of the second multiplication circuits 82A to 82A given by
The values X1, X2, X3 output from 2C are respectively U
These are the current values of the drive currents to be actually applied to the phase, V-phase, and W-phase coils 11, and these values X1, X2, X3 are given to the corresponding PWM converters 83A to 83C, respectively.

Then, each of the PWM converters 83A to 83C is
The first to third PWM signals S4A to S4C and the first to third reference signals are controlled by controlling the pulse width of each 50 [μs] cycle pulse based on the supplied values X1, X2, X3. The signals S5A to S5C are generated.

Actually, each of the PWM converters 83A to 83C is
As shown in FIG. 17, the supplied values X1, X2
, X3 are set in an internal register (not shown), and the value X1
, X2, X3 are positive, the values X1, X2, X3
Is supplied to a down counter (not shown) in the first PWM pulse signal generating circuit 85A at every rising edge of the PWM pulse signal S11 having a period of 50 [μs] given from the counter timer control circuit 65 of the arithmetic processing block 40. set.

This down counter is provided by the CPU clock (0.1 μs) of the arithmetic processing block 40 (FIG. 11).
]), The counter value is decremented at each rising edge, and stopped at zero value. Therefore, the output of the first PWM pulse signal generation circuit 85A becomes a logic "1" level until the count value of the down counter becomes zero, and becomes a logic "0" level after the counter value becomes zero. .

At the next rising edge of the PWM pulse signal S11, the values X1, X2,.
X3 is set again in the down counter of the first PWM pulse signal generation circuit 85A, and the above processing is repeated.

Therefore, the first PWM pulse signal generating circuit 8
From 5A, the values X1, X2, X3 stored in the registers
Is updated, the first to third PWM signals S4A to S4A to have a constant pulse width Ton proportional to the values X1, X2, and X3.
S4C is output and the second PWM pulse signal generation circuit 8
5A, reference signals S5A to S5 of logic "0" level
C is output.

On the other hand, in each of the PWM converters 83A to 83C, if the values X1, X2 and X3 are negative values, the absolute values are calculated and converted into positive integers, and then these values are converted to positive integers. 2 is set in a down counter (not shown) in the PWM pulse signal generation circuit 85B.

As a result, at this time, the values X1, X2, and X3 stored in the registers are updated from the second PWM pulse signal generation circuit 85B in the same manner as the above-described first PWM pulse signal generation circuit 85A. Up to the value X1,
The first to third constant pulse width Ton proportional to X2 and X3
PWM signals S4A to S4C are output. At this time, first PWM pulse signal generation circuit 85B outputs reference signals S5A to S5C of logic "0" level.

Thus, in the first to third PWM converters 83A to 83C, the supplied values X1, X2,
The first to third PWM signals S having a pulse width Ton corresponding to X3
4A to S4C and first to third reference signals S5A to S5C
Is generated and sent to the coil drive block 34 of the power board 24 via the third cable 33.

(4) Relationship between Coil Drive Current and Output Torque
Drive current I applied to each phase 11, V-phase and W-phase coil 11
The relationship between u, Iv, and Iw and the rotational torque output to the outside via the output shaft 18 (hereinafter, referred to as output torque) will be described.

First, when drive currents Iu, Iv, and Iw are applied to the U-phase, V-phase, and W-phase coils 11, the magnetic flux density at which these U-phase, V-phase, and W-phase coils 11 intersect is φu, Assuming φv and φw, the output torque T (θp)
Is expressed by the following equation using the magnetic pole angle θp of the rotor shaft 6 of the motor unit 2.

[0153]

(Equation 32)

Is given as follows. In the equation (32), K0 is the driving current Iu, Iv,
It represents a constant coefficient value when Iw is applied.

Here, each of the U-phase, V-phase and W-phase coils 11
The drive currents Iu, Iv, Iw applied to

[0156]

[Equation 33]

[0157]

(Equation 34)

[0158]

(Equation 35)

The magnetic flux densities φu, φv, φw are respectively expressed by the following equations:

[0160]

[Equation 36]

[0161]

(37)

[0162]

(38)

Is obtained.

Therefore, the output torque T (θp) is obtained by substituting the equations (33) to (38) into the equation (32), and

[0165]

[Equation 39]

Can be expressed as follows.

Accordingly, it can be seen that in the AC servomotor 1, an output torque proportional to the magnitude of the drive currents Iu, Iv, Iw applied to each coil 11 can be obtained.

(5) Software Control in AC Servo Motor 1 Next, the arithmetic processing block 40 of the AC servo motor 1
The software control in FIG. 11 will be described.

In the arithmetic processing block 40, the CPU 60 operates the counter / timer control circuit 65 as described above.
Based on the servo interrupt signal S10 given by the controller and the corresponding program stored in the ROM 61, the motor rotation control arithmetic processing, the phase advance control processing,
A temperature compensation control process and a serial communication control process are executed. Hereinafter, processing of the CPU 60 in each of these processing modes will be described.

(5-1) Processing of CPU 60 in Motor Rotation Control Calculation Processing Mode The processing of the CPU 60 in the motor rotation control calculation processing mode is, as described above, a specified rotation position, a specified rotation speed, or a specified rotation speed given from the host controller. The purpose is to calculate a target rotation torque T0 according to the specification of the rotation torque value.

When the designated rotational position Pref is given from the host controller, the CPU 60 sets the target rotational torque T0 to the rotor shaft magnetic pole rotation angle stored in the register 41 by the rotor shaft rotation angle detection processing block 42. The rotational position Pm of the output shaft 18 (FIG. 1) is calculated based on the rotational position Pm1.

[0172]

(Equation 40)

[0173]

[Equation 41]

By calculating respectively, the target rotation speed Vmref for the designated rotation position Pref and the current rotation speed Vm of the output shaft are calculated. Then, from the equations (40) and (41) obtained as described above, the following equation is obtained.

[0175]

(Equation 42)

By executing the above calculation, the target rotation torque T0 is calculated.

[0177] The designated rotational speed V
When ref is given, the current rotation speed Vm of the output shaft 18 is calculated using the equation (41), and based on the rotation speed Vm, the following equation is obtained.

[0178]

[Equation 43]

By calculating the target rotation torque T0,
Is calculated. When the designated rotational torque Tref is given from the host controller, this is directly used as the target rotational torque T0.

In these equations (40) to (43), S represents a Laplace operator, and Kpp, Kvi, and Kvp each represent a control gain parameter set by an upper controller. The control gain parameters Kpp, K
By changing the values of vi and Kvp, the response of the AC servomotor 1 to the specified rotation angle Pref and the specified rotation speed Vref can be changed.

The specific processing procedure of the CPU 60 in the motor rotation control calculation processing mode is shown in FIG.
Shown in

When the designated rotation angle Pref is given from the host controller, the CPU 60 firstly stores the first and second absolute angle sensor data D1 stored in the register 41.
A, D1B based on the magnetic pole rotation speed of the rotor shaft 6 (hereinafter, referred to as
Nm is calculated (step SP1).

Note that the rotor shaft magnetic pole rotation speed Nm refers to the first to the first of the rotor shaft magnetic pole angle sensors 22 as the rotor shaft 6 rotates.
The number of rotations is defined as one rotation of a magnetic flux change by a pair of adjacent N and S poles of the resin magnet 25 detected by the fourth Hall elements 26A to 26D. In this embodiment, since the resin magnet 25 is magnetized into four poles, the number of rotations Nm of the magnetic pole of the rotor shaft becomes 2 when the rotor shaft 6 makes one rotation mechanically.

The rotor shaft magnetic pole rotation speed Nm is calculated according to the rotor shaft magnetic pole rotation speed detection processing procedure shown in FIG.
The phase θ of the first and second one-turn absolute angle sensor signals S1A and S1B represented by sin θg and cos θg, respectively.
g is calculated by software processing based on the first and second absolute angle sensor data D1A and D1B stored in the register 41 (step SP1A), and the phase θg of the planetary gear mechanism 16 of the torque amplifying unit 3 is calculated. The gear ratio N is multiplied (step SP1B), the result of the multiplication is divided by 2π, and the number of magnetic poles of the resin magnet 25 of the rotor shaft magnetic pole angle sensor 22 (FIG. Can be obtained by multiplying by half the value Np of 4) (step SP1C).

As shown in FIG. 18, the CPU 60
The rotor shaft magnetic pole rotation speed Nm calculated in this manner is compared with the rotor shaft magnetic pole rotation angle data P stored in the register 41.
Based on m1,

[0186]

[Equation 44]

Using Pm0 given by the following equation as an initial value,

[0188]

[Equation 45]

By executing the above calculation, the rotation angle Pm of the output shaft 18 at that time is calculated (step SP).
2).

Then, the CPU 60 sets the designated rotation angle Pref.
By subtracting the rotation angle Pm from the above, an error Pe (hereinafter, referred to as a rotation angle error) with respect to the designated rotation angle Pref is detected (step SP3).

Subsequently, the CPU 60 determines that the rotation angle error P
The target rotation angle Vmref with respect to the specified rotation angle Pref is calculated by multiplying e by the proportional gain Kpp (step SP4).

Next, the CPU 60 calculates the rotation speed Vm of the output shaft at that time by differentiating the rotor shaft magnetic pole rotation angle Pm1 stored in the register 41 (step SP5), and thereafter calculates the target speed calculated in step SP4. The speed error Ve is calculated by subtracting the rotation speed Vm calculated in step SP5 from the rotation speed Vmref (step SP6).

Subsequently, the CPU 60 adds the following equation to the speed error Ve.

[0194]

[Equation 46]

Are sequentially multiplied by the speed integral gain and the proportional gain Kvp given by (Step SP7 and Step S7).
P8). Thus, the target rotation torque T0 can be obtained.

In the motor rotation control arithmetic processing mode, the CPU 60 sends the designated rotation speed Vref from the host controller.
Is applied, the process starts from step SP6. When the rotational torque Tref is applied, this is used as it is as the target rotational torque T0 in the register 4.
1 is stored.

(5-2) Processing of CPU 60 in the phase advance control processing mode First, the phase advance control will be described. U phase, V of motor unit 2
Drive currents Iu supplied to the phase 11 and W phase coils 11,
Iv and Iw are controlled in the torque-three-phase current signal conversion processing block 43 and the current control processing block 44, respectively, so as to satisfy the equations (33), (34) and (35).

At this time, if the rotor 9 is rotating at a high speed, for example, each of the inverter circuits 52A-5
Even when the drive currents Iu, Iv, Iw as given by the equations (33), (34) and (35) are given to the 2C, the drive currents actually flowing through the U-phase, V-phase and W-phase coils 11 I
u, Iv, and Iw are delayed by the impedance of the coil 11, and as a result, the output torque decreases.

The phase advance control is to solve this problem by the following equation.

[0200]

[Equation 47]

[0201]

[Equation 48]

[0202]

[Equation 49]

Each of the U-phase, V-phase and W-phase coils 1
This is control in which the phases of the drive currents Iu, Iv, Iw applied to 1 are advanced in advance by a correction value θoff corresponding to the rotation speed of the rotor 9 in advance.

Then, in practice, the CPU 60 calculates the correction value θoff as the phase advance control process using the rotational speed Vm calculated in step SP5 in FIG.

[0205]

[Equation 50]

The first to third current command values Ur and Vr generated in the torque-three-phase current signal conversion processing block 43 are calculated and given to the torque-three-phase current signal conversion processing block 43. , Wr are controlled so as to be advanced by the correction value θoff as shown in the equations (47) to (49).

In equation (50), Kv is the output shaft 1
8 is a gain that determines the relationship between the magnitude of the rotation speed and the amount of phase advance correction, and is a constant determined by the specifications of each coil 11 of the motor unit 2.

(5-3) Processing of CPU 60 in Temperature Compensation Control Processing Mode In an AC servomotor using a permanent magnet, heat is generated by current flowing through the coil and heat is generated by eddy current loss. Such heat changes the magnetic properties of the permanent magnet. Generally, when a coil current is applied in a high temperature atmosphere and a high magnetic flux density is applied, the permanent magnet is demagnetized. For this reason, the maximum value of the coil current is generally designed to be low in order to provide safety.

The temperature compensation control is a control for effectively utilizing the magnetic characteristics of the permanent magnet by controlling the maximum current allowed by the temperature.

In the case of this embodiment, as shown in FIG. 9, the temperature sensor signal S14 output from the temperature sensor 29 of the control
Is stored in the register 41 through the fourth analog / digital conversion circuit 48 as the temperature sensor data D14.

The CPU 60 calculates the maximum value Imax of I0 in the equations (33) to (35) based on the value TH of the temperature sensor data D14 according to the following equation.

[0212]

(Equation 51)

By controlling the torque-three-phase current signal conversion processing block 43 based on the calculation result, the drive current Iu flowing through each of the U-phase, V-phase and W-phase coils 11 of the motor unit 2 is calculated. , Iv, Iw. Kth is a temperature coefficient determined according to the temperature characteristics of the permanent magnet (in the present embodiment, the rotor magnet 8 of the rotor 9 (FIG. 1)).

(5-4) Processing of the CPU 60 in the Serial Communication Processing Mode In the serial communication processing mode, the CPU 60 communicates with the host controller, inputs control commands and change parameters, or performs internal monitoring. Send a signal.

(5-5) Processing of CPU 60 in External Force Estimation Processing Mode In the case of the AC servomotor 1, the arithmetic processing block 40 executes the above-described motor rotation control arithmetic processing, phase advance control processing, and temperature compensation. In addition to the control processing and the serial communication control processing, the magnitude of the external force (load torque) applied to the output shaft 18 can be estimated.

In this case, the output torque Tm of a general motor, the mechanical rotation angle θm of the rotor, the external force Td applied to the output shaft, and the output angle of the gear mechanism (hereinafter referred to as the rotation angle of the output shaft) The relationship with θg can be represented as shown in FIG.

That is, the mechanical rotation angle θm of the rotor
Subtracts the structural load torque Tdm of the gear mechanism from the output torque Tm.

[0218]

(Equation 52)

Can be calculated by multiplying Jm represents the moment of inertia of the rotor, and Dm represents the coefficient of friction between the rotor and the bearing.

The rotation angle θg of the output shaft is equal to the external force Td.
And a multiplication result Tdl obtained by multiplying the structural load torque Tdm of the gear mechanism by the gear ratio N of the gear mechanism (hereinafter referred to as a structural output shaft load torque) Tdl, and the addition result Tdl
Where

[0221]

(Equation 53)

Can be calculated by multiplying Jl is the moment of inertia in the gear mechanism, Dl
Denotes a coefficient of friction in the gear mechanism, and S denotes a Laplace operator.

The structural load Tdm of the gear mechanism is obtained by subtracting the multiplication result obtained by multiplying the rotation angle θg of the output shaft by the gear ratio N of the gear mechanism from the mechanical rotation angle θm of the motor rotor. Can be calculated by multiplying by the spring coefficient Kg.

Based on this principle, the CPU 60 estimates the magnitude of the external force applied to the output shaft 18 from the outside according to the following procedure shown in FIG.

That is, the CPU 60 first generates an initial value of an appropriate size as an estimated value of external force (hereinafter, referred to as an estimated value of external force) Tde. The estimated value of external force Tde and the structural value of the planetary gear mechanism 16 The following equation is added to the result of addition with the output shaft load torque Tdl.

[0226]

(Equation 54)

Is multiplied to calculate a mathematical model rotation angle θgm of the output shaft 18.

By subtracting this rotation angle θgm from the actual rotation angle θg of the output shaft 18 obtained by the calculation, the error of the rotation angle θgm of the mathematical model with respect to the actual rotation angle θg (hereinafter referred to as a model error) Call) E
θg is calculated and the model error Eθg is

[0229]

[Equation 55]

The estimated external force Tde is calculated by multiplying the estimated gain given by In the equation (55), Ka is a constant positive coefficient value.

Then, the CPU 60 calculates the external force estimated value T
The above-described calculation processing is repeated while sequentially updating de to the newly obtained external force estimated value Tde. As a result, the model error Eθg converges to a zero value by repeating such calculation processing, and accordingly, the estimated external force Tde also approaches the magnitude of the external force actually applied to the output shaft 18.

The estimated external force Tde when the model error Eθg becomes 0 can be estimated as the external force actually applied to the output shaft 18, and the CPU 60 calculates this value as the estimated external force obtained by the calculation. Let it be Tde.

Thereafter, the CPU 60 transmits the external force estimated value Tde to the upper controller, or antagonizes the external force applied to the output shaft 18 based on the external force estimated value Tde under the control of the upper controller. And control of the output torque, the generation and output control of the output torque exceeding the external force, or the generation and output control of the output torque below the external force.

In the case of this embodiment, the magnitude of the external force applied to the output shaft 18 is estimated based on the rotational displacement of the output shaft 18 detected by the one-turn absolute angle sensor 21 as described above. It has been made like that. Therefore, the speed reduction mechanism of the torque amplifying unit 3 (the planetary gear mechanism 16)
Is constructed such that the input shaft (rotor shaft 6) has sufficient reversible driveability (back drivability) to cause displacement in proportion to an external force applied to the output shaft 18.

(6) Operation and Effect of the Present Embodiment In the above configuration, the AC servomotor 1 uses one of the control boards 23 based on a specified rotation angle, a specified rotation speed, or a specified rotation torque given from the host controller. In the chip microcomputer 27, the drive currents Iu, Iv, to be applied to the U-phase, V-phase and W-phase coils 11
First to third current command values Ur, Vr, W
r is calculated, and the first to third PWM signals S4A to S4C based on the calculated first to third current command values Ur, Vr, Wr are sent to the coil drive block 34 of the power board 24.

The coil driving block 34 of the power board 24 supplies the supplied first to third PWM signals S4A to S4A.
Generating drive currents Iu, Iv, Iw based on S4C,
This is applied to the U-phase, V-phase and W-phase coils 11 to rotate the rotor 9.

In the AC servomotor 1, the control board 23 and the power board 24 as control means for controlling the rotation of the rotor 9 are integrated with the rotor 9 and the stator including the stator core 10A and the coil 11 as described above. Since it is housed inside the motor case 4, the amount of connection wiring with the outside can be reduced remarkably,
The amount of wiring for the entire actuator system can also be reduced.

In this case, the PWM converter 83
A to 83C (switching elements) are housed inside the motor case 4 made of a conductive material. Therefore, for example, when a PWM signal (switching signal) is externally supplied to the AC servomotor as in a conventional AC servomotor. In comparison, the adverse effect of switching noise on the outside can be remarkably reduced. Therefore, a relatively common second cable 32 for connecting the AC servomotor 1 to the host controller can be used.

Further, in the AC servomotor 1, the rotor shaft magnetic pole angle sensor 22 is arranged near the rotor 9 inside the motor case 4, and the rotor rotation angle θm is obtained based on the output of the rotor shaft magnetic pole angle sensor 22. As a result, high-precision and high-speed positioning can be performed without increasing the thickness of the rotor shaft 6, and the overall size can be reduced.

In addition, as described above, the rotor shaft magnetic pole angle sensor 2
Since 2 is arranged near the rotor 9 inside the motor case 4, there is little mechanical fluctuation and the rotation angle of the rotor shaft 6 can be detected stably.

Further, in the AC servomotor 1, since the temperature sensor 29 is provided near the rotor magnet 8 inside the motor case 4, the temperature sensor 2
9, the drive current Iu which can be actually applied to each coil 11 according to the magnetic characteristics of the rotor magnet 8,
The upper limits of Iv and Iw can be obtained accurately and easily, and the upper limits of the drive currents Iu, Iv and Iw are increased by an amount corresponding to the upper limit of the drive currents Iu, Iv and Iw including the safety. The maximum output torque can be increased.

Further, in the AC servomotor 1, since the rotor 9 and the control circuit for controlling the rotation of the rotor 9 are arranged on a plane, the AC servomotor 1 can be constructed in a small and flat shape.

Further, the AC servomotor 1 has an advantage that the structure is simple and the number of parts is small, so that the assembling work and the adjusting work at the time of manufacturing can be simplified.

According to the above configuration, the control board 23 for controlling the rotation of the motor unit 2 under the control of the host controller
And the power board 24 is housed in the motor case 4 integrally with the rotor 9 and the starter.
The amount of wiring connected to the outside of the C servomotor 1 can be significantly reduced, and the amount of wiring of the entire actuator system can be reduced, thus simplifying the configuration of the entire actuator system. A servo motor can be realized.

Further, the rotor shaft magnetic pole angle sensor 22 for detecting the rotation angle of the rotor shaft 6 is arranged near the rotor 9 inside the motor case 4, so that the rotor shaft 6 can be formed with high accuracy and high speed without making the rotor shaft 6 thick. An AC servomotor that can perform positioning and thus can be downsized while improving performance can be realized.

Further, by providing the temperature sensor 29 near the rotor magnet 8 inside the motor case 4, based on the output of the temperature sensor 29,
The upper limits of the drive currents Iu, Iv, Iw that can be actually applied to each coil 11 can be accurately and easily obtained according to the magnetic characteristics of the rotor magnet 8, and the drive current Iu
, Iv, and Iw can be increased and the maximum output torque can be increased, thereby realizing an AC servomotor capable of improving the performance, as compared with the case where the upper limit is set including safety as in the past. it can.

(7) Other Embodiments In the above-described embodiment, the case where the present invention is applied to the AC servomotor has been described. However, the present invention is not limited to this. A rotating shaft (rotor shaft 6 in the present embodiment) freely pivoted, and driving means for rotating the rotating shaft (in the present embodiment, a rotor 9, a stator core 10, and a stator comprising a coil).
If these are actuator devices housed in a housing (motor case 4 in the present embodiment), the present invention can be widely applied to various other actuator devices.

Further, in the above-described embodiment, for example, a case has been described in which the rotor magnet 8 is magnetized to four poles. However, the present invention is not limited to this. For example, the number of poles may be eight or other. It may be magnetized.

Further, in the above-described embodiment, the case has been described where the control board 23 and the power board 24 as control means for controlling the rotation of the rotor 9 are formed separately, but the present invention is not limited to this. The invention is not limited to this, and may be formed integrally.

Further, in the above-described embodiment, a case is described in which one-chip microcomputer 27 controls the rotation of rotor 9 based on a specified rotation angle, a specified rotation speed, or a specified rotation torque given from a host controller. However, the present invention is not limited to this. For example, the rotation of the rotor 9 may be controlled based on a pre-programmed rotation angle or a change pattern of the rotation speed or the rotation torque.

Furthermore, in the above-described embodiment, the rotor shaft magnetic pole angle sensor 22 as the rotation shaft rotation displacement detecting means for detecting the rotation displacement of the rotor shaft 6 is replaced with the resin magnet 25 (first Component) and the first
Although the description has been given of the case where it is configured with the fourth to fourth Hall elements 26A to 26D (second configuration part), the present invention is not limited to this, and various other configurations can be widely applied.

Further, in the above-described embodiment, a case has been described in which the magnetic pole angle θp of the rotor shaft 6 is detected as the rotational displacement of the rotor shaft 6, but the present invention is not limited to this, and the magnetic pole angle θp Other rotational displacement information may be detected.

Further, in the above-described embodiment, the coil 11 is used as magnetic field generating means for generating a magnetic field having a magnitude corresponding to the current values of the driving currents Iu, Iv, Iw supplied from the power board 24 in the rotor section 2. Although the description has been given of the case where the present invention is applied, the present invention is not limited to this, and various other magnetic field generating means can be widely applied.

Further, in the above embodiment, U
Drive current I applied to each phase 11, V-phase and W-phase coil 11
Although the case where the drive current value detecting means for detecting the current values of u, Iv and Iw is constituted by the coil 53 (FIG. 10) has been described, the present invention is not limited to this, and the drive of various other structures is also possible. The current value detecting means can be widely applied.

Further, in the above-described embodiment, the one-chip computer 27 of the control board 23 has an RS-communication function as a serial communication function for communicating with the host controller.
Although the case where the 232C serial communication function and the synchronous serial communication function are provided has been described, the present invention is not limited to this, and another serial communication function may be provided.

Further, in the above-described embodiment, the case has been described where the torque amplifying means for amplifying the rotational torque generated in the motor section 2 is constituted by the planetary gear mechanism 16 as shown in FIG. However, the present invention is not limited to this, and various other configurations can be widely applied.

Further, in the above-described embodiment, the one-rotation absolute angle sensor 21 as the output shaft rotational displacement detecting means for detecting the rotational displacement of the output shaft 18 is connected to the resin magnet 19.
And the first and second Hall elements 20A and 20B have been described. However, the present invention is not limited to this, and various other configurations can be widely applied.

Further, in the above-described embodiment, the first and second signals output from the one-rotation absolute angle sensor 21 are output.
The load torque applied to the output shaft 18 from the outside based on the rotation absolute angle sensor signals S1A and S1B and the first and second rotor shaft magnetic pole angle sensor signals S2A and S2B based on the output of the rotor shaft magnetic pole angle sensor 22 ( Although the calculation means for detecting the external force) has been described as being constituted by the one-chip microcomputer 27, the present invention is not limited to this, and it may be provided separately from the one-chip microcomputer 27. good.

Further, in the above-described embodiment, each drive current Iu based on each drive current Iu, Iv, Iw applied to each of the U-phase, V-phase, and W-phase coils 11 detected on power board 24. , Iv, and Iw are feedback-controlled to reduce the influence of fluctuations in the power supply voltage. However, the present invention is not limited to this, and the present invention is not limited to this. Drive currents Iu, Iv, I
The current value of w may be controlled.

Actually, as such a method, the magnitude of the power supply voltage Vcm is detected, and based on the detection result, the gain Gv in the current control processing block 44 is calculated by the following equation.

[0261]

[Equation 55]

It is sufficient to make it variable as shown in FIG.

[0263]

As described above, according to the present invention, in an actuator device in which a rotor and a stator are housed in one space formed by a housing, a rotation angle detecting means for detecting a rotation angle of the rotor is provided. And calculating means for determining a current command value to be given to the drive circuit based on the detection result of the rotation angle detecting means are provided in the space, so that the amount of wiring to the outside can be significantly reduced. Thus, an actuator device that can simplify the configuration of the actuator system can be realized.

According to the present invention, in an actuator device in which a rotor and a stator are accommodated in one space formed by a housing, a rotation angle detecting means for detecting a rotation angle of the rotor, and a detecting means for the detecting means. A calculation means for determining a current command value to be given to the drive circuit based on the result is provided in the space, and the rotation angle detection means and the calculation means are mounted on the same substrate, so that a connection with the outside can be obtained. Thus, the amount of wiring can be significantly reduced, and an actuator device that can simplify the configuration of the actuator system can be realized.

Further, according to the present invention, in an actuator device in which a rotor and a stator are housed in one space formed by a housing, a drive circuit for supplying a drive current to the stator and a rotation angle of the rotor are detected. Rotation angle detection means, a temperature detection means for detecting the temperature of the driving permanent magnet constituting the rotor, and a current command value to be given to the drive circuit based on the detection results of the rotation angle detection means and the temperature detection means. Computing means in the space,
The rotation angle detection means, the temperature detection means and the calculation means are mounted on the same substrate, so that the calculation means can reduce the amount of wiring between the outside and the detection results of the temperature detection means. The upper limit of the current command value to be given to the drive circuit can be easily detected based on this, and an actuator device that can improve the performance can be realized.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of an AC servomotor according to the present embodiment.

FIG. 2 is a schematic diagram illustrating a configuration of a rotor and a rotor shaft magnetic pole angle sensor;

FIG. 3 is a schematic diagram illustrating a positional relationship between a rotor and a stator core.

FIG. 4 is a schematic diagram illustrating configurations of a stator and a power board.

FIG. 5 is a schematic diagram illustrating a configuration of a torque amplifying unit.

FIG. 6 is a characteristic curve diagram for describing a magnetization pattern of a resin magnet in a one-turn absolute angle sensor.

FIG. 7 is a characteristic curve diagram showing a waveform of a one-rotation absolute angle sensor signal.

FIG. 8 is a schematic diagram illustrating a configuration of a control board.

FIG. 9 is a block diagram illustrating a configuration of a control board.

FIG. 10 is a circuit diagram showing a configuration of a power board.

FIG. 11 is a block diagram showing a configuration of a one-chip microcomputer.

FIG. 12 is a characteristic curve diagram for describing a magnetization pattern of a resin magnet in the rotor shaft magnetic pole angle sensor.

FIG. 13 is a characteristic curve diagram showing waveforms of first and second sensor signals (first and second rotor shaft magnetic pole angle sensor signals).

FIG. 14 is a block diagram illustrating a configuration of a rotor shaft rotation angle detection processing block.

FIG. 15 is a block diagram illustrating a configuration of a torque-three-phase current signal conversion processing block.

FIG. 16 is a block diagram illustrating a configuration of a current control processing block.

FIG. 17 is a schematic diagram used for explaining a process performed by the PWM converter;

FIG. 18 shows a CPU in a motor rotation control processing mode.
FIG. 4 is a block diagram for explaining the arithmetic processing of FIG.

FIG. 19 is a block diagram illustrating a motor shaft magnetic pole rotation speed detection processing procedure.

FIG. 20 is a block diagram showing a mathematical model of a relationship between a rotor and a gear mechanism.

FIG. 21 is a block diagram for describing arithmetic processing of a CPU in an external force estimation processing mode;

[Explanation of symbols]

1 ... AC servo motor, 2 ... Motor part, 3 ... Torque amplifier, 4 ... Motor case, 6 ... Rotor shaft, 8 ...
... rotor magnet, 9 ... rotor, 10, 10A-1
0F: stator core, 11, 11A to 11F: coil, 16: planetary gear mechanism, 18: output shaft, 19, 2
5 ... Resin magnet, 20A, 20B, 26A-26
D: Hall element, 21: one-turn absolute angle sensor, 2
2 ... rotor shaft magnetic pole angle sensor, 23 ... control board, 2
4 Power board 27 27 1-chip microcomputer 29 Temperature sensor 31-33 Cable
34 ... Coil drive block, 40 ... Calculation processing block, 42 ... Rotor shaft rotation angle detection block, 43 ...
Torque-three-phase current signal conversion processing block, 44... Current control processing block, 52A to 52C... Inverter circuit, 60... CPU, 64... Serial communication input / output circuit, 83A to 83C. S1A, S1B
... one-rotation absolute angle sensor signal, S2A, S2B ... rotor shaft magnetic pole angle sensor signal, S3A to S3C ... drive current detection signal, S4A to S4B ... PWM signal, S13 ...
... Temperature sensor signals, Ur, Vr, Wr ... Current command values,
Iu, Iv, Iw: drive current, θp: magnetic angle, P
m1 ... rotor shaft magnetic pole rotation angle, Pref ... designated rotation angle, Vref ... designated rotation speed, Tref ... designated rotation torque, T0 ... target rotation torque, Tde ... external force estimated value.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-8-87330 (JP, A) JP-A-60-257754 (JP, A) JP-A-3-93442 (JP, A) JP-A-63-1987 43592 (JP, A) JP-A-10-105206 (JP, A) JP-A-9-133586 (JP, A) JP-A-3-25894 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02K 29/08 H02K 21/14 H02P 6/12 H02K 7/116

Claims (4)

(57) [Claims] An actuator device in which a rotor rotatably supported and a stator for generating torque in the rotor are housed in one space formed by a housing, wherein a drive current is supplied to the stator. A drive circuit for supplying, a rotation angle detection means for detecting a rotation angle of the rotor, and a calculation means for determining a current command value to be given to the drive circuit based on a detection result of the rotation angle detection means, in the space. An actuator device, comprising: 2. An actuator device in which a rotor rotatably supported on a rotor and a stator for generating a torque on the rotor are housed in one space formed by a housing, wherein a drive current is supplied to the stator. A drive circuit for supplying, a rotation angle detection means for detecting a rotation angle of the rotor, and a calculation means for determining a current command value to be given to the drive circuit based on a detection result of the detection means, provided in the space, An actuator device, wherein the rotation angle detecting means and the calculating means are mounted on the same substrate. 3. The actuator device according to claim 2, wherein said arithmetic means includes communication means for performing serial communication with an external device. 4. An actuator device in which a rotatably supported rotor and a stator for generating torque in the rotor are housed in one space formed by a housing, wherein a drive current is supplied to the stator. A drive circuit for supplying, a rotation angle detection means for detecting a rotation angle of the rotor, a temperature detection means for detecting a temperature of a driving permanent magnet constituting the rotor, the rotation angle detection means and the temperature detection means Computing means for determining a current command value to be given to the drive circuit based on the detection result in the space, wherein the rotation angle detecting means, the temperature detecting means, and the computing means are mounted on the same substrate. An actuator device characterized in that: