JPH046434A - Six-axis operation monitoring apparatus - Google Patents

Abstract

PURPOSE:To make it possible to perform monitoring in real time by providing a means for measuring the angular displacement of a motion base and a means for the operation of six axes. CONSTITUTION:One end of each of six shakes is connected to a motion base, and the other end is connected to a fixed base. A freely rotatable joint is provided at each connecting point. The motion base is made to operate in six degrees of freedom. At this time, the displacements of the shakers are measured with, e.g. displacement gages, and A/D conversion is performed. The amounts of the angular displacements of the motion base are measured with, e.g. gyroscopes, and A/D conversion is performed. The displacements 1 of the shakers and the angular displacements 2 of the motion base are inputted at a sampling period inherent to an operating device 3. An operating part 3-1 is operated by a program stored in a program memory part 3-2. In a data memory part 3-3, inherent coordinate data, the data of the neutral lengths of the shakers and the intermediate results of operations are stored. Motion displacements 3-4 as the results of the operations undergo A/D conversion, and the results are outputted. In this way, the translation-displacement amounts are algebraically operated in a short time, and monitoring can be performed in real time.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides six degrees of freedom of movement (back and forth,
This invention relates to a device for monitoring actual motion on a motion base that performs left/right, up/down, roll, pinch, and yaw movements.

[Conventional technology]

In general, a six-degree-of-freedom motion base uses six hydraulic cylinders to perform translational movements in three axes, such as back-and-forth movement, left-right movement, and up-and-down movement, as well as rotational movements around three axes, such as yaw, pitch, and roll movements. It is configured so that not only each exercise can be performed, but also a combination of these exercises can be performed.

An example thereof will be explained with reference to FIGS. 2 and 3. 34
is a motion base, and the motion base 34 is supported by six hydraulic cylinders 4 to 9 placed on a fixed base 35 fixed on the floor. Both ends of these hydraulic cylinders 4 to 9 are connected to bearing points 10 to 15 on a fixed base 35, as shown in FIG. and are supported by bearing points 16 to 21 on the motion base 34, respectively. Reference numerals 22 to 27 are electrohydraulic servo valves attached to the hydraulic cylinders 4 to 9, respectively, and the servo valves 22 to 27 operate the hydraulic cylinders 4 to 9 in accordance with control signals obtained from a control circuit to be described later. 2
8 to 33 are displacement detectors for detecting the displacement of the hydraulic cylinders 4 to 9.

In the six-degree-of-freedom motion base configured as described above, the hydraulic cylinders 4 to 9 operated by the electro-hydraulic servo valves 22 to 27 are controlled by the six-degree-of-freedom motion output from the calculation processing device 37 of the control circuit shown in FIG. By performing servo control to follow the command signal X, the motion base 34 operates in six degrees of freedom.

As shown in FIG. 4, the six-degree-of-freedom motion command signal X+ output from the calculation processing device 37 is input to the calculation device 38. This calculation device 35 inputs the command signal Xl, calculates a displacement command signal L1 for the hydraulic cylinders 4 to 9, and outputs it to the servo control circuit 36. This servo control circuit 36 inputs the displacement command signal t and the signal Lf of the displacement detectors 28 to 33 of each hydraulic cylinder 4 to 9, and causes the motion base 34 to perform a motion corresponding to the six degrees of freedom movement command signal XI. The hydraulic cylinders 4 to 9 are controlled so as to

The six free motion command signals Xl outputted from the calculation processing device 37 in this manner are input to the calculation device 38, and are converted into strokes of each of the hydraulic cylinders 4 to 9 by the calculation device 38.

Therefore, by using the position of each hydraulic cylinder 4-9 as a feedback signal for the servo control device, the motion base 34 can be given the required six degrees of freedom movement.

In this way, motion with six degrees of freedom can be realized, but since there is no means to directly observe all of the motions with six degrees of freedom, there is a method of calculating the actual displacement of each cylinder as information. This method uses an arithmetic expression that calculates the amount of displacement of each exciter from the amount of motion displacement of six degrees of freedom. Conversely, this calculation formula cannot algebraically calculate the six degrees of freedom displacement from the displacement of each vibrator, so the observed displacement of the shaker is This is a method of performing a convergence calculation so that the quantity matches the calculation result of the above-mentioned calculation formula.

[Problem to be solved by the invention]

The conventional method described above has the following problems.

Namely.

(1) To improve calculation accuracy, the number of calculation repetitions increases,
This requires a lot of calculation time, and real-time performance is lost.

(2) If the number of calculation repetitions is reduced to shorten the calculation time, the calculation accuracy will deteriorate and the function as a monitor will be lost.

(3) In order to achieve high speed and high precision, an expensive and large-sized computer is required, resulting in a loss of economic efficiency.

An object of the present invention is to provide a six-axis motion monitoring device that can realize highly accurate calculation results in a short time with an inexpensive equipment configuration.6 [Means for Solving the Problems] To achieve the above object. , the present invention calculates the angular displacement directly,
Means for measuring, the displacement of the vibrator, and means for quickly calculating the operational displacement of the six axes from the angular displacement obtained by the above-mentioned means were provided. In order to achieve high-speed and high-precision calculations, we provided a means for measuring angular displacement, which is necessary to change the calculation method from convergence calculation to algebraic calculation, and which can be directly measured. Furthermore, although the angular displacement measuring instrument is expensive, the arithmetic circuit can be realized at a very low cost, making it cheaper than a method using a large computer.

[Effect]

Before describing the monitor calculation method, we will explain how to calculate the displacement of the exciter from the six-axis motion displacement.

Both ends of the vibrator are connected to one movable base with six degrees of freedom (hereinafter referred to as the motion base) and the other to a stationary point on the foundation or base (hereinafter referred to as the fixed base). The connection point has a structure that allows for the tilting of the vibration exciter via a rotatable joint. The stationary coordinate system whose origin is one point ○ on the fixed base is ○-xyz, and the moving coordinate system whose origin is one point O' on the motion base is ○'-x'y'z.
shall be. The position vector of the cylinder is obtained by equation (1).

Ωr = A+ 10RBt (+ = 1 to 6) ・
...(1) In Uni, R is a position vector connecting ○ and O', which changes forward and backward, left and right, and up and down of the motion-based translation. Further, B is a position vector of a point attached to the fixed base of vibration exciter j, which is a constant vector.

A is the position vector of the point attached to the motion base of the vibration exciter l as seen from the stationary coordinate system, and it changes depending on the rotational motion of the motion base, such as yaw, pitch, and roll.

That is, the relationship of equation 1 (2) holds true.

A, =A□・T...(2) Here, A1. is the position vector of the point at which the exciter i is attached as seen from the motion coordinate system fixed on the motion base, and is a constant vector. T is the roll angle φ.

This is a transformation matrix from a moving coordinate system to a stationary coordinate system when the pitch angle is θ and the yaw angle is ψ, and is expressed by equation (3).

Therefore, given each rotational angular displacement, Equation 1 (2) is obtained.

When A1 is determined from (3) and a translational displacement is given, the direction vector of the vibrator i is determined from the formula (1), and this magnitude 1J21+ becomes the length of the vibrator. The amount of displacement of the vibrator is the difference from the length of the vibrator j when the angular displacement and translational motion principle is O.

Next, the method of monitor calculation will be described.

By measuring the amount of angular displacement, it can be output directly as a monitored amount.

The amount of translational displacement can be calculated using the following method. formula(
By transforming 1), the following formula is obtained.

Qtl = IR-M1+...(
4) Here, Ms is -A I + B t, and when an angular displacement is given, it becomes a constant vector for each exciter according to equations (2) and (3).

By squaring both sides of equation (4), equation (5) is obtained.

I Q112=lR12+1M1+2-2R-gate,
...(5) In the same way, the formula for the other three vibration exciters is calculated as follows: Equation (%) ).

...(9) The vector on the left side is obtained from the displacement amount and angular displacement amount of the vibrator using equations (2) and (3). Similarly, the matrix on the right side is also obtained from the angular displacement using equations (2) and (3).

The translational displacement vector is obtained by multiplying equation (9) by the inverse matrix of the matrix on the right side.

As a case where the inverse matrix on the right side does not exist, there is a case where the roll angle and the pitch angle are O at the same time5. In this case, the formula (
In 9), omit the row or column related to the two coordinates, find the X and Y coordinates of the translational displacement, and for the two coordinates, use the obtained displacement amount to calculate one of equations (5) to (8). It is determined by

In this way, the angular displacement obtained directly can be used to algebraically calculate the translational displacement.

It can perform calculations at high speed and with high precision.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

Displacement 1 of the vibrator and angular displacement 2 of the motion base are input to the calculation device 3. The displacement of the vibrator is 1. For example, an output signal from a displacement meter attached to the vibrator is A/D converted and input. Further, the amount of angular displacement of the motion base is 1. For example, a gyroscope is installed on the motion base, and the output signal is A/D converted and input. In addition, in order to synchronize input data, input data is input at a unique sampling period.

The arithmetic device 3 includes arithmetic units 3-1. Program storage unit 3-2
．． It is composed of a data storage section 3-3.

The calculation unit 3-1 operates according to a program stored in the program storage unit 3-2. A digital signal processor can also be used to speed up sine and cosine calculations. The data storage unit 3-3 stores intermediate calculation results in addition to unique /I target data and data on the neutral length of the vibrator.

The motion displacement 3-4 as the calculation result is outputted via the D/A converter. Also, in order to synchronize the output data,
Similar to input data, it is output at a unique sampling period.

A schematic processing flow example of the program stored in the program storage section 3-2 will be described below.

Step 1: Input the amount of vibration exciter displacement and the amount of motion base angular displacement.

Step 2: Calculate the coordinate transformation matrix T.

Step 3: Length of four exciters 1Ωi, l Qaft
J2 h+, IQ dew 1 is calculated from the neutral length stored in the data storage section 3-3 and the input displacement amount.

Step 4: Position vectors Bl, BJ in the stationary coordinate system of the attachment point of the shaker on the fixed base.

B k, B and the position vector A im, AJII in the motion coordinate system of the attachment point of the exciter on the motion base? Akme Axm is read from the data storage unit 3-3, and the vector A1.A1. Calculate MJI Mk+A and its size.

Step 5: Calculate the vector on the left side of equation (9).

Step 6: Calculate the matrix on the right side of equation (9).

Step 7: Determine whether roll angle φ and pitch angle θ are both 0. If established, proceed to step 9. If not established, proceed to the next step.

Step 8 Calculate the inverse matrix of the matrix calculated in Step 6. Multiply the obtained inverse matrix by the vector calculated in step 5 to calculate the amount of translational displacement. Proceed to step 10.

Step 9 An inverse matrix is calculated for the two-by-two matrix that is involved in the longitudinal and horizontal translational displacement of the matrix calculated in Step 6.

The obtained inverse matrix is multiplied by the component involved in the longitudinal and horizontal translational displacement of the vector calculated in step 5 to calculate the translational displacement in directions other than the upward and downward directions. The vertical translational displacement is calculated by substituting the already obtained calculation result into either equation (5) or 8),
Obtained by calculation.

Step 10: Output the angular position and the calculated translational displacement amount.

By repeating steps 1 to 10 above, six-axis motion displacements are output in response to continuously changing input data.

〔Effect of the invention〕

According to the present invention, by using a means for directly measuring the amount of motion-based angular displacement, the amount of translational displacement can be calculated relatively easily algebraically, so that the following effects are achieved.

(1) Since the calculation can be performed in a sufficiently short time compared to the excitation period, real-time monitoring is possible.

(2) Since results are obtained by algebraic operations, calculation accuracy can be obtained compared to convergence operations.

(3) It can be realized with an inexpensive arithmetic circuit.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a six-axis motion monitoring device according to an embodiment of the present invention, FIG. 2 is a perspective view of a conventional six-axis motion monitoring device, and FIG. 3 is a schematic explanatory diagram of FIG. FIG. 4 is a conventional control block diagram. DESCRIPTION OF SYMBOLS 1... Vibration displacement detection section, 2. Motion base angular displacement detection section, 3... Arithmetic device, 3-1... Arithmetic section, 3-2
...Program storage section, 3-3 Data storage section, 4.
...Motor displacement output section.

Claims (1)

[Claims] 1. Six vibration exciters, a base that moves in six degrees of freedom: forward/backward, left/right, up/down, roll, pitch, and yaw; and a base that rotates the vibration exciters. A six-degree-of-freedom motion base consisting of a freely connected universal joint, a drive section that generates a driving force, and a control section that calculates and controls displacement command signals for each of the vibrators from the six-degree-of-freedom command signals. , means for measuring angular displacement, and means for calculating the amount of displacement of each of the vibration exciters and the motion of six axes of front/rear, left/right, up/down, roll, pitch, and yaw than the amount of angular displacement; A six-axis motion monitoring device characterized by being provided with.