JPS5834865B2 - Vector calculation circuit - Google Patents

Description

[Detailed description of the invention] This invention provides two
Regarding the circuit that calculates the magnitude of the composite value of vector quantities, in more detail, the vector input is measured with a measuring instrument that can measure only one direction and its opposite direction, which are arranged at right angles to each other, and the output is actually measured. The present invention relates to a device for obtaining an approximate value of the magnitude of an input vector quantity without compositing.

For example, if we consider the case of measuring acceleration, which is a vector quantity, with an accelerometer, the first
It is measured using the method shown in the figure.

In other words, accelerometers can generally only measure in one direction and the opposite direction, so in order to measure the vector quantity, 2
Arrange the sensors at right angles to each other, measure the component Vx in the X-axis direction and the component ■y in the y-axis direction, and use a vector synthesis circuit to calculate v = 7 illusion ■v] to find its size. was.

However, it is quite difficult to perform analog calculations of squares and square roots using electric circuits, and since circuit components are used in ways that are easily affected by environmental conditions, there are problems with accuracy. It had the drawback of being expensive.

Another method is to use three sensors 3,
4.5 are placed 120 degrees apart, and the acceleration is the 0 degree direction component■.

, 120 degree direction component V120 and 240 degree direction component V
240, and input the absolute value into a maximum value detection circuit as shown in FIG. 6, for example, to generate three components.

+V1□. There is a method of taking the maximum value between
Also, although the circuit can be easily constructed with only a maximum value detection circuit and a diode and a resistor, it has the disadvantage of being expensive because it requires three sensors.

The purpose of this invention is to use only two sensors when measuring vector quantities, which can be done at low cost with a relatively simple circuit.
Moreover, it is an object of the present invention to provide a circuit that can obtain an approximate value of the magnitude of a vector quantity with relatively high precision.

The circuit of the present invention approximately calculates the magnitude of a vector input divided into two orthogonal portions by sensors arranged at right angles to each other, without using a combining circuit.

In order to achieve this objective, the present invention includes a coefficient multiplier circuit that multiplies the output of a sensor by a selected coefficient, an adder circuit that adds the output of the desired coefficient multiplier circuit, and each sensor as described in detail below. It consists of a maximum value detection circuit that detects the maximum value of the output of the adder circuit and the output of the adder circuit.

This invention will be explained below using the drawings.

FIG. 4 shows a system diagram of an embodiment of the present invention.

Sensors 1 and 2 are arranged at right angles as shown in FIG.

Assuming that, for example, there is an acceleration input from the input direction in the figure, the angle between the input direction and the sensor 1 is assumed to be θ.

In Fig. 4, the coefficient multiplier circuit 6 outputs the sensor 1')
The coefficient multiplication circuit 7 is a circuit that multiplies the output vy of the sensor 2 by 0.707 (, /E ).

The coefficient to be multiplied is determined as follows.

In Fig. 5, the input vector is OP, and the vector OP
Let OA and OB be the projections of on the X and Y axes.

Since sensors 1 and 2 are placed on the X and Y axes, respectively, O
The sizes of A and OB become Vx and Vy.

Let OQ be the bisector of angle XOY.

Let the ratio of projection OM to OA to OQ of OA be a coefficient of Vx, and the ratio of projection ON to OB to OQ of OB be a coefficient of Vy.

A circuit 8 is connected to the output side of the coefficient multiplication circuits 6 and 7, and is a circuit for adding OM and ON in FIG.
This is a circuit that adds 7Vy.

The output 0.707 (Vx+Vy) of this adder circuit enters the maximum value detection circuit together with the outputs Vx and Vy of the sensors 1 and 2.

The maximum value detection circuit 9 detects the maximum value among the inputs V x r V y and 0.707 (Vx+Vy), and outputs V=M'axVx, Vy, 0.707 (Vx+V
y).

The coefficient multiplier circuits 6, 7 and the adder circuit 8 are composed of one operational amplifier and several resistors, and can be manufactured at low cost and stable under environmental conditions.

The maximum value detection circuit 9 can be easily constructed using a diode and a resistor, for example, as shown in FIG.

Figure 7 shows the characteristics when using the circuit in Figure 4, and the error is maximum at θ-22°30' and θ67°30'.
At that time, the output ■ is V=0.924VR with respect to the true value ■R
This results in an error of 7.6 tai.

This is the maximum error of 1 when using three sensors in Figure 2.
Considerably better results can be obtained compared to 34φ.

Looking at Figure 7, the horizontal axis is the angle of the input direction, and the vertical axis is the ratio of the sought value ■ to the true value vR. At θ-σ, Vx matches the true value, and θ-0 to 2 ff 30 'In ', Vx
is close to the true value.

At θ-45°, the output of adder circuit 8 is 0.707 (
Vx+Vy) matches the true value, θ-22°30'~6
At 7°30', 0,707 (Vx + Vy) is close to the true value.

Also, at θ=9, Vy matches the true value, and θ-67°
Vy is close to the true value between 30' and 90°.

The same holds true in the range of θ>90°.

However, it is assumed that Vx and Vy take absolute values.

FIG. 8 shows a system diagram of another embodiment of the present invention, in which the sensors are arranged in the same way as in FIG.
Let it be y.

The coefficient multiplication circuits 10a and 10b have a coefficient of 0.866 (
Vi), the coefficient multiplication circuit 1 11a and 11b are coefficient multiplication circuits that multiply the input by a coefficient 0.5 (7), and the output of the sensor 1 is the coefficient multiplication circuit 10.
a and 11a, the output of sensor 2 is applied to coefficient multiplication circuit 1.
Connected to 0b and Ilb.

The coefficient to be multiplied is determined as follows. In FIG. 9, if the input vector is OP and the projections of the vector OP onto the X and Y axes are OA and OB, then OA and OB are
The magnitude of is V x +vy.

Let the trisectors of ZXOY be OQ and OR.

The coefficient of the coefficient multiplication circuit 10a is the projection O of OA to OQ.
The ratio of M1 to OA, the coefficient of 10b is the ratio of projection ON2 to OB to OR of OB, the coefficient of 11a is the ratio of projection OM2 to OA to OR of OA, and the coefficient of 11b is O
Let be the ratio of the projection ON to the OQ of B and OB.

The circuit 12a is connected to the output sides of the coefficient multiplication circuits 10a and 11b, and is a circuit that adds the output 0.866Vx and o, svy.
Connected to the output side of 0b, its outputs 0.5Vx and 0.8
This is a circuit that adds 66Vy.

The outputs of these adder circuits 12a and 12b (J sensor 1゜2
It is connected to the maximum value detection circuit 9 together with the output of.

The maximum value detection circuit 9 receives the inputs Vx, Vy, 0.86
6Vx 15■y and 0.5Vx+0.866Vy
Detects the largest one among them and outputs V −MaxVx,
Vy, 0.866Vx+0.5Vy, 0.5Vx
+0.866Vy is output.

Fig. 10 shows the characteristics when using the circuit of Fig. 8, and the error is θ=15°, θ=4! It is maximum when 0 and θ=75°, and the output ■ at that time is V=0.966 VR and 3.
The error is 4%, and the accuracy is even better than that of the previous embodiment.

Looking at FIG. 10, Vx matches the true value at θ-0°, and Vx is close to the true value at θ=0° to 15°.

0.866 Vx+ 0.5 V at θ=30°
y matches the true value and is 0. at θ=15° to 45°.
866Vx+0.5Vy is close to the true value.

At θ=60', 0.5 Vx+0.866 V
y matches the true value and is 0. at θ=45° to 75°.
5Vx+0.866Vy is close to the true value.

Also, at θ=90°, Vy matches the true value, and θ=7
In the range of 5° to 90°, vy is close to the true value.

The same holds true in the range of θ>90°.

Setting V X + V y to take an absolute value is similar to the previous example.

As described above, according to the present invention, the coefficient multiplier circuit multiplies the sensor output by a coefficient, the adder circuit performs the desired addition, the output is compared with the measured values of two sensors, and the maximum value is selected. With only two sensors, the value can be determined stably, inexpensively, and accurately without using complicated circuits such as square or square root circuits that are easily affected by environmental conditions.

Note that this circuit can be similarly applied to the case where ZXOY is divided into four or more equal parts, and the accuracy improves as the number of equal parts increases.

Furthermore, although the above description has been made for two-dimensional vector quantities, it can also be applied to three-dimensional vector quantities.

[Brief explanation of drawings]

Figure 1 is a diagram showing the arrangement of sensors and input directions, Figure 2 is a diagram showing a conventional example of calculating vectors by arranging three sensors every 12σ, and Figure 3 is a diagram showing the second diagram using three sensors. 4 is a circuit diagram of an embodiment of the present invention, FIG. 5 is a principle diagram for determining the coefficients of the circuit of FIG. 4, and FIG. 6 is a maximum value used in the present invention. Figure 7 is a diagram showing an example of the detection circuit; Figure 7 is a characteristic diagram when using the circuit in Figure 4;
9 is a circuit diagram of another embodiment of the present invention, FIG. 9 is a principle diagram for determining the coefficients of the circuit of FIG. 8, and FIG. 10 is a characteristic diagram when the circuit of FIG. 8 is used. 1.2: Sensor, 6, 7, 10a, 10b. 11a, 11b: coefficient multiplication circuit, 8, 12a. 12b: Adder circuit, 9: Maximum value detection circuit.

Claims (1)

[Scope of Claims] 1. In a measurement circuit that measures components of a person's Kirktle quantity and determines the magnitude of its input vector quantity, the orthogonal values of the respective measurement values obtained from the outputs of sensors arranged on two orthogonal axes are provided. A circuit that obtains a projection on an equal dividing line that equally divides a plurality of orthogonal angles formed by the axes, that is, the measured value is multiplied by the cosine value of the measured value of the sensor for the angle between the equal dividing line and each axis of the orthogonal axis. a coefficient multiplication circuit; an addition circuit that takes as input the output of the coefficient multiplication circuit for each of the equal dividing lines and calculates the sum thereof; and an addition circuit that takes as input the output of the sensor and the output of the addition circuit and calculates the maximum of the inputs. A vector calculation circuit that consists of a selected maximum value detection circuit and calculates an approximate value of the magnitude of an input vector without combining sensor measurement values. 2. The vector calculation circuit according to claim 1, comprising two coefficient multiplication circuits in which the equal dividing line is a bisector, and the coefficient multiplied by the coefficient multiplication circuit is cos45°=0.707. 3 The equal dividing line is a third equal dividing line, and the coefficient multiplied by the coefficient multiplication circuit is CO530' = 0.866 and cos5
2. The vector calculation circuit according to claim 1, comprising two coefficient multiplication circuits each having a coefficient of Q'0.5 corresponding to each equal dividing line and two addition circuits corresponding thereto.