JPH0251019A - Rotary position/speed operation apparatus - Google Patents

Abstract

PURPOSE:To obtain a position signal of high accuracy by a method wherein a control circuit forms three-mode function indication control signals from the result obtained by comparing a single vibration signal with a specific reference value to output the same to an incremental and decremental counter. CONSTITUTION:A control circuit 12a consists of two comparators 121a, 121b and a control signal generator 122, and forms three-mode function indication control signals of count increment, count stop and count decrement from the comparing result of the single vibration signal V{=Asin(thetam-thetas) thetam-thetas} being the output signal of a phase operator 11 with the different values +ea, -ea of the comparators 121a, 121b to apply the same to an incremental/decremental counter 13. By this method, in the case of ¦thetam-thetax¦<=(1/2LSB of thetas), the counter 13 receives a function indicating control signal of count stoppage to stop the counting of a clock signal CLK. Therefore, fine vibration is eliminated and a highly accurate position signal can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a rotational position/speed calculation device, and more particularly to a rotational position/speed calculation device with improved accuracy in calculation of rotational position and rotational speed.

(Prior Art) Conventionally, this type of rotational position/speed calculation device calculates a two-phase signal Asi from a rotational position detector with respect to the rotational position θm of a rotating body.
When nθeat Acosθs (A is an arbitrary constant) is output, the rotational position and rotational speed are calculated from the two-phase signals, and is configured as shown in FIG. 4, for example.

In the figure, the rotational position/speed calculation device is composed of a phase calculation unit 11, a control circuit 12, an up/down counter 13, and a function generator 14.

First, the phase calculator 11 receives an output signal A from a rotational position detector (not shown) attached to a rotating body (not shown).
It is configured to output a - simple harmonic signal V=A sin (θs - θS) based on sin θs A cos θm and the signals sin θs and cos θ9 given from the function generator 14. That is, in the phase calculator 11, A is calculated by the two-phase signal and the signal from the function generator 14.
sinθs ” cosθs −Acosθs−5in
The calculation θs=A sin (θs−〇,) is performed.

The control circuit 12 includes a comparator 120, which compares the simple harmonic signal V with a predetermined reference value e, and if v>e, the logic level tt HppV (if e, the logic level # L IT The control circuit 1 outputs two types of function designation control signals.
2, the reference value e = O(V) is set, so the signal output from the comparator 120 is V>0, that is, O1>
If θs, then jlH”, and conversely, if v<0, that is, O1×θs, then “L”.

The up/down counter 13 receives input signals such as a count up/count down (U/D) signal and a clock (C
LK) signal and an enable signal (ENA) signal,
The operation is set as follows according to these input signals6. That is, when the ENA signal is "L", the up/down counter 13 can count, and when the ENA signal is "H", the up/down counter 13 can count.
”, the up/down counter 13 becomes incapable of counting. Therefore, when the ENA signal is in the state of “It LIT”, if the U/D signal is “L”, the up/down counter 13 will count down, and if the U/D signal is “IIH”, the up/down counter 13 will count down. The down counter 13 is set to count up.Thereby, the up/down counter 13 receives a function designation control signal (“H” or rtL) from the control circuit 12.
), the CLK signal is counted up or down depending on the timing. That is, the up/down counter 13 counts up in synchronization with the CLK signal when θs>θs, and conversely counts down in synchronization with the CLK signal when O1 is less than O5.

Furthermore, the function generator 14 takes in the output signal θs from the up/down counter 13 and generates the signal sinθs゜co.
It is configured to generate sθs and output it to the phase calculator 11.

The operation of the rotational position/velocity calculation device configured as described above will be explained below.

First, output signals A sin θm and A cos θs from a rotational position detector interlocked with the rotating body are supplied to the phase calculator 11, and a signal sin θs from the function generator 14 is supplied.

Cos θs is also supplied to the phase calculator 11 in the same way. In this phase calculator 11, two-phase signals Asinam, Aco
V based on sθm and signals sinθs, C0IIθs
= A sin e g ・cosθs −A cos
θsll5jnθg = A sin (θm−θS)
calculations are performed. This signal V = A sin (
θm-θs) is compared with a predetermined reference value e by the comparator 120 of the control circuit 12, and if v>Ol, that is, θs>O5, the output signal of It HIT will be changed to v>Ol, that is, θs<O3. If so, the output signal of tr L tp is output as a function designation control signal.

At this time, the up/down counter 13 is capable of counting because the ENA terminal is grounded and fixed at "L". /D signal) is “L11”, it is counted down, and if it is “IIH”, it is counted up.In other words, when O1>θs, CLK
Counts up in synchronization with the signal, and when θs is less than θs, C
Countdown in synchronization with the LK signal.

Here, the up/down counter 13 is
The simple harmonic signal v=0, which is the output of (θ.

-05)=O, and since O5 is a discrete value, two values are alternately output with θs in between in the steady state. The function generator 14 receives the output signal θ from the up/down counter 13.

is taken in, the signals sin θs and cos θs are generated and output to the phase calculator 11.

Therefore, in the rotational position/speed calculation device configured as described above, by determining the duty of the "H" level l"L" level of the U/D signal per unit time,
This means that a speed signal can be obtained.

(Problems to be Solved by the Invention) In the conventional rotational position/speed calculation device described above, since the output signal θs of the up/down counter L3 is a discrete value, the input signal θs and the output signal θs match in most cases. There's nothing to do. That is, since the simple harmonic signal V output from the one-phase calculator 11 takes either a positive or negative value, the function designation control signal output from the control circuit 12 also has a value of 11)I21 or "L". Takes one of these values. As a result, the up/down counter 13 continues to count up or count down.

Therefore, even if the signal sin θm from the rotational position detector,
Even if cos θs maintains a constant value, the up/down counter 13 repeats counting up/down, so at least the ILSB (least significant bit), in other words, 1
The disadvantage is that the signals sin θs and cos θm are treated as fluctuating signals for the force count. In other words, in conventional rotational position/velocity calculation devices, even though the rotating body is actually stopped, it appears to repeat forward and reverse rotations between two points corresponding to ILsB (with slight vibrations). ) has the disadvantage that a position signal like the one shown above can be obtained.

Of course, if the rotational position/speed calculation device is configured to discard the least significant bit, the above disadvantages can be overcome, but in that case, the accuracy must be commensurate with the capabilities of the rotational position/speed calculation device and the rotational position detector. There was a problem in that it was not possible to obtain a position signal.

The present invention has been proposed to solve the above problems, and its purpose is to provide a rotational position/speed calculation device that can obtain highly accurate rotational position signals.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides output signals sin θm, cos
θs and a separately given signal sinθateosθs
a phase calculator that outputs a simple harmonic signal from -, a control circuit that outputs a function designation control signal based on the simple harmonic signal from this phase calculator and a predetermined reference value, and a function designation control signal from this control circuit. An up/down counter that counts clock signals according to a control signal, and based on the output signal θs from this up/down counter, the signal sinθs,
cos θ.

and a function generator that generates and provides the function generator to the phase calculator.
The control circuit generates three types of function designation control signals of count up, count stop, and count down based on the result obtained by comparing the simple harmonic signal with a specific reference value, and outputs the control signals to the up/down counter. Features.

The control circuit also includes a comparator that compares the simple harmonic signal from the phase calculator with different reference values, and performs function designation control in three ways: count up, count stop, and countdown based on the comparison results of these comparators. It is preferable to include a control signal generator that generates a signal, and in this case, it is desirable that the different reference values are each a value corresponding to 172 of the resolution of the output signal θs of the up/down counter.

(Function) In the present invention, the control circuit generates function designation control signals in three aspects of count up, count stop, and count down from the result obtained by comparing the simple harmonic signal with a specific reference value, and controls the up/down counter. Output to. Therefore, the input signals sinθs, cosθ of the rotational position/speed calculation device
When s maintains a constant value, the function designation control signal stops counting, so up-down counting cannot be performed. As a result, the input signal sinθs, c
When osθs is a constant value, unnecessary vibrations disappear,
When θm is a −constant value, θs also maintains a constant value.

Here, in the control circuit, the simple harmonic signal from the phase calculator is compared with different reference values by two comparators. These different reference values are selected to be values corresponding to 172 of the resolution of the output signal θs of each up/down counter, and the control signal generator that has taken in the comparison results from the comparator can count up, stop counting, Function designation control signals for three types of countdown are generated and output to the up/down counter. And the up/down counter is
10m-〇, when 1≦(1/2 LSB of θs).

Since a function specifying control signal for stopping counting is supplied, there is no need to count up or count down.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

First, FIG. 1 is a block diagram of a rotational position/speed calculation device according to this embodiment.

This rotational position/speed calculation device is different from the rotational position/speed calculation device shown in FIG. (+e, , -ea) is configured to form three types of function designation control signals: count up, count stop, and count down, and give them to the up/down counter 13; the other configurations are the same. It is. Therefore, other components that are the same as those of the rotational position/velocity calculating device shown in FIG. 4 are given the same reference numerals to avoid duplication, and their explanations will be omitted.

Therefore, the control circuit 12a has comparators 121a and 121b that compare the simple harmonic signal V from the phase calculator 11 with two different reference values (+eatea), and uses the results of these comparisons to count up, stop counting, The control signal generator 122 generates function designation control signals for three types of countdown.

Here, V = Asin (θm - θs) white θs - 〇, the value equivalent to +1/2 L S B of θs is +e, and the value equivalent to 1/2 L S B of Og is -e , the comparator 121a outputs the l(HI+ level when V)+e, the L7 level when V<+e, and the comparator 1
21b is the It Hu level when V>-8°, and V<
-e, the control signal generator 1 outputs an L” level signal.
22 respectively. In addition, the control signal generator 122
is configured to output a function designation control signal for counting enabled/uncountable as the ENA signal of the up/down counter 13, and a function designation control signal for counting up/countdown as the U/D signal of the up/down counter 13. . In other words, the relationship between the input signal (single harmonic signal V) and the output signal (function designation control signal) of the control circuit 12a is as shown in Table 1 below.

Table 1 Next, FIG. 2 is a circuit diagram showing a specific configuration of the control signal generator 122 used in this embodiment. The control signal generator 122 includes an EX-NOR circuit (-number circuit) 122a and an AND circuit 122b. Comparator 12
Each output signal from 1a, 121b is EX-N
It is applied to each input terminal of the OR circuit 122a and the AND circuit 122b. Then, the output of the EX-NOR circuit 122a is used as the ENA signal, and the output of the AND circuit 1
The output of 22b is output as a U/D signal. Control signal generator 122 and comparator 1 like this
21a and 121b, the function designation control signals shown in Table 1 above can be obtained.

Next, the operation of this embodiment will be explained. First, output signals As1nθm and Acosθm from a rotational position detector interlocked with a rotating body (not shown) are supplied to the phase calculator 11. Also, the signal sin from the function generator 14
θs and cosOs are also added to the phase calculator 11, and the phase calculator 11 performs a calculation to obtain A sin (θm-05). Simple harmonic signal V=As from the phase calculator 11
in(θs-〇,) is given to the control circuit 12a, and the control circuit 12a inputs the signal V and two reference values (+ear-00
) are compared by the comparators 121a and 12tb.

Here, the comparator 121a is at the "tgH" level when V)10e, and the "L It" level when V(+e), and the comparator 121b is at the "H" level when V>-ea;
When a, the control signal generator 12 outputs the “L I9 level signal.
Output to 2. In the control signal generator 122, these output signals are sent to the EX-NOR circuit 122a and the AND circuit 12.
2b to each input terminal of EX-N.

The R circuit 122a outputs u Hn as the ENA signal only in the case of ◯ in Table 1, and outputs "L" in other cases. On the other hand, the AND circuit 122b outputs 'H' as the U/D signal only in the case of ■ in Table 1, and in other cases
IL" is output.

The up/down counter 13 has an ENA signal of 1 (L).
Counting becomes possible when I+, and if the function designation control signal (U/D signal) at this time is L'', the countdown starts, U
If the /D signal is "H", the count is up. That is, the up/down counter 13 counts up in synchronization with the CLK signal in the case of ■ in Table 1, and counts down in synchronization with the CLK signal in the case of ■ in Table 1.

Here, the up/down counter 13 is 10. -θS1≦(1/2 LSB of θs), and θs (output of the up/down counter 13) does not change.

Therefore, if the input signal sin θsr CO2O3 is constant.

1Vl=IAsin(f3.-θs) I valve IA(θm-
A signal satisfying θ6≦lea can be obtained. That is, according to this embodiment, the signals sin θm, cos θs
If is constant, it is possible to obtain a rotational position signal that does not have slight vibrations, and it is possible to obtain a position signal that maintains at least twice the accuracy of a conventional rotational position/speed calculation device.

In addition, in the case of this embodiment, the speed signal indicates how many pulses of an effective CLK signal (CLK signal applied to the up-down counter 13 during ■ or ■ above) are applied to the up-down counter 13 per unit time. You can get by asking.

This is similar to the case where the speed signal is obtained from the output signal of the pulse encoder.

Note that FIG. 3 shows an example of the speed calculation circuit used in this embodiment, and in the same figure, the speed calculation circuit 7 is
Integrating circuits 74, 75 consisting of inverting circuits 70, 71, AND circuits 72, 73, analog arithmetic circuit OP, resistor R, and capacitor C, and resistors R and 74 that amplify the output signals from these integrating circuits 74, 75. Analog calculation circuit OP
and an amplifier circuit 76 consisting of. The above-mentioned E
When the NA signal and the U/D signal are input, the AND circuit 72.
A CLK signal is applied from one side of 73 to one of integration circuits 74 and 75, which is integrated and outputted from the amplifier circuit 76 as an analog speed signal with a positive value during forward rotation and a negative value during reverse rotation. It turns out.

(Effects of the Invention) As described above, according to the present invention, two
The simple harmonic signal obtained from the phase signals A sin θm and A cos θs is compared with a specific reference value, and from the comparison result, three types of function designation control signals of count up, count stop, and count down are generated and given to the up/down counter,
Since the up/down counter stops counting when the two-phase signal is constant, there is an effect that a highly accurate position signal can be obtained. Further, since a reference value corresponding to 1/2 LSB is set in the control circuit, there is an advantage that there is no one count error and no slight vibration occurs.

[Brief explanation of the drawing]

1 to 3 show an embodiment of the present invention,
Figure 1 is a block diagram, Figure 2 is a circuit diagram of the control circuit, and Figure 3 is a block diagram.
The figure is a circuit diagram of the speed calculation circuit, and Figure 4 is the conventional rotation position/
FIG. 2 is a block diagram showing a speed calculation device.

Claims (3)

[Claims] (1) A phase calculator that outputs one simple harmonic signal from the output signals sin θ_m, cos θ_m from the rotational position detector to which the rotating body is attached and the separately given signals sin θ_s, cos θ_s, and a simple harmonic signal from this phase calculator. A control circuit that outputs a function designation control signal based on a vibration signal and a predetermined reference value, an up/down counter that counts clock signals in accordance with the function designation control signal from this control circuit, and a Output signal θ_
s, and a function generator that generates the signals sin θ_s and cos θ_s and provides them to the phase calculator, and calculates the rotational position and rotational speed of the rotating body, the control circuit comprising: , a rotation characterized in that, from the result obtained by comparing the simple harmonic signal with a specific reference value, three types of function designation control signals of count up, count stop, and count down are generated and output to the up/down counter. Position/velocity calculation device. (2) The control circuit includes a comparator that compares the simple harmonic signal from the phase calculator with different reference values, and counts up, stops counting, etc. based on the comparison results of these comparators.
2. The rotational position/speed calculation device according to claim 1, further comprising a control signal generator that generates three types of countdown function designation control signals. (3) Different reference values in the control circuit are each 1/2 of the resolution of the output signal θ_s of the up/down counter.
2. The rotational position/speed calculation device according to claim 2, wherein the value corresponds to .