KR20190094574A - Automatic initialization method of 6 axis motion platform for simulator - Google Patents

Abstract

The present invention relates to an automatic initialization method of a six-axial motion platform for a simulator, which improves competitiveness in terms of the maintenance and costs of a system. The automatic initialization method comprises the steps of: measuring positions and speeds of first to sixth servo motors and outputting the same to a control unit as a pulse value; determining whether the difference between an input pulse value and an output pulse value is greater than or equal to a preset reference value; stopping pulse input when the difference is greater than or equal to the reference value; and setting a position where first to sixth actuators are not changed for a predetermined time as an origin.

Description

Automatic initialization method of 6 axis motion platform for simulator

The present invention relates to an automatic initialization method of a six-axis motion platform for simulators, and more particularly, to determine the lowest unit value, which is the origin point at the time of initial driving, in a motion platform for a simulator using a natural incremental encoder without adding an external sensor. The automatic initialization method of the 6-axis motion platform for the simulator to be initialized by performing the following.

According to Doosan Encyclopedia, "rotary encoder" is a sensor that measures the rotation angle. It is a representative sensor used to measure the rotation angle or rotation speed of an electric motor or an engine.

Incremental rotary encoders generate a pulse each time the axis rotates a certain amount of angle. That is, the angle of the axis can be detected by counting the number of pulses. Absolute rotary encoders can detect the absolute position of the axis by several signal lines. "

According to Patent Publication No. 10-2017-0110751 (Triple Degree of Freedom Motion Platform for Virtual Reality Experience), "It relates to a three degree of freedom motion platform for a virtual reality experience that implements a motion simulator in conjunction with virtual reality experience content. In more detail, the base plate 10, the upper plate 20, the first, second and third movement means 31, 32, 33 are installed, but the first and second movement means 31, 32 are both sides. , The third movement means 33 is installed in a row so as to axially rotate back and forth by connecting the joint in the same direction as the upper plate in the front and rear position between the first and second movement means, connected to the upper plate during the pitch movement by the third movement means Since the joint of the first and second movement means becomes the rotation center and rotates at a larger angle than the conventional art, the virtual reality experience is maximized in an extreme sports simulator such as a motorcycle and a ski jump. "Called It has indicated bar.

Patent Publication No. 10-2017-0110751 (3 degree of freedom motion platform for virtual reality experience)

[Naver Knowledge Encyclopedia] Rotary Encoder (Doosan Encyclopedia)

The six-axis motion platform for the simulator, consisting of six electric actuators, measures the rotational position and speed of the rotor using a rotary encoder mounted on the servomotor. It can be classified into absolute type and incremental type. Absolute position encoder can maintain the absolute position of the rotor because it can measure the absolute position of the rotor.However, it is required to continuously supply power through the backup battery to the encoder to prevent the position loss even during the resting period of the servomotor. . On the other hand, natural incremental encoders measure relative position, so no battery is required, but the origin must be determined at every startup. This origin determination process is called initialization, and manual or automatic initialization is possible. Conventionally, the output signal is used as a reference point by adding a sensor to the outside for automatic initialization, but there are disadvantages in that the system becomes complicated, the price increases, and maintenance becomes inconvenient.

The present invention is to solve the above-described problems, the simulator 6 for initializing by performing the process of determining the lowest unit value of the origin at the time of initial drive in the motion platform for a simulator using a natural incremental encoder without adding an external sensor 6 Its purpose is to provide an automatic initialization method for the axis motion platform.

According to the present invention for solving the above problems, the motion platform performs a lowering operation according to a pulse input for operating each servomotor with an initialization start command, and at the same time, between the pulse output value and the pulse input value of the encoder in the algorithm. When the motion platform reaches the lowest position of the origin, the difference between the two values increases because the output pulse value is kept constant as the input pulse value increases because it can no longer descend by the mechanical limit. If the difference between the two pulses is equal to or greater than the preset reference value, stop the pulse input and set the pulse at that position to zero to determine the position as the origin, and if the process is performed on all axes, terminate the initialization. It is composed.

In an embodiment, the lower plate of the motion platform, the upper plate of the motion platform located above the lower plate in isolation from the lower plate of the motion platform, and the first to sixth actuators which are lifted or lowered by the electric force, First to sixth servomotors installed on each of the first to sixth actuators to supply electric power according to a control signal to the first to sixth actuators, and a control signal for adjusting the height and inclination of the upper plate to the first to sixth actuators. Method for auto-initializing the six-axis motion platform for the simulator using a control unit for transmitting to the sixth servo motor and a natural incremental encoder; The natural incremental encoder receives positions and speeds of the first to sixth servomotors from the control unit, transfers positions and speeds to the first to sixth servomotors, and transmits positions and speeds of the first to sixth servomotors. Measuring a speed and outputting the pulse value to the controller; The control unit determines whether a difference between an input pulse value and an output pulse value of the natural incremental encoder is greater than or equal to a preset reference value; Stopping the pulse input by the natural increase type encoder when a difference between an input pulse value and an output pulse value of the natural increase type encoder is greater than or equal to a reference value; The control unit includes the step of setting the position of the first to the sixth actuator by continuing to descend for a predetermined time, the position that does not go down any longer and does not change for a predetermined time.

In an embodiment, the naturally increasing encoder is provided inside the servomotor.

In an embodiment, the naturally increasing encoder is provided inside the controller.

According to the preferred effect of the present invention, by stably implementing the automatic initialization process of the six-axis motion platform for the simulator, because the system does not rely on the battery or external sensor used in the prior art for the initialization, the system becomes simpler and maintenance and price aspects There is an advantage in improving competitiveness.

1 is a perspective view schematically showing a six-axis motion platform according to the present invention.
Figure 2 is a view for explaining the neutral position and the lowest unit value of the six-axis motion platform according to the present invention.
Figure 3 is a view for explaining the change in the length of the actuator when the lowering of the six-axis motion platform according to the present invention.
Figure 4 is a flow chart showing an automatic initialization method of the six-axis motion platform according to the present invention.
5 is a graph showing the amount of change in the pulse signal during the initialization process of the six-axis motion platform according to the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a perspective view schematically showing a six-axis motion platform according to the present invention, Figure 2 is a view for explaining the neutral position and the lowest unit value of the six-axis motion platform according to the present invention, Figure 3 is 6 according to the present invention As a figure for explaining the change in the length of the actuator when the axis motion platform is lowered, the six-axis motion platform for the simulator is provided with a top plate 11 on the top of the lower plate (12).

In addition, between the upper plate 11 and the lower plate 12 is configured to enable six degrees of freedom using the first to sixth electric actuator (Actuator) 13, the first to supply a power for this A sixth servomotor 14 is provided.

The servo motor 14, which is a key component of the actuator 13, measures the position and speed of the rotor through a rotary encoder. The rotary encoder may be configured as a separate component. Encoder is classified into Absolute Tye and Incremental Type.In case of using Absolute Encoder, it is necessary to install additional backup battery to prevent position loss. In order to determine the origin (bottom position), additional sensors need to be installed.

Since the system is complicated by the addition of a battery or the addition of a sensor, and side effects such as a price increase and maintenance inconvenience occur, a natural increase type encoder is used in the present invention.

Comparing the neutral position (A) and the lowest position (B, C) shown in Figures 2 and 3 can see the rising position and the lowering position of the upper plate 11, which is due to the mechanical limit of the actuator itself.

Meanwhile, in the present specification, the initialization refers to a process of determining the corresponding position as the origin after the upper plate 11 of the motion platform descends to the lowest position.

Looking at the components for implementing the present invention, the lower plate of the motion platform, the upper plate of the motion platform located above the lower plate and isolated from the lower plate of the motion platform, the first lifting or lowering is performed by the electric force And sixth to sixth actuators, the first to sixth servomotors installed on each of the first to sixth actuators to supply electric power according to a control signal to the first to sixth actuators, and the height and inclination of the upper plate are adjusted. The control unit for transmitting a control signal to the first to sixth servo motor and a natural increase type encoder is required.

In the present invention using such a device configuration, the initialization method having the flow shown in FIG. 4 is implemented.

The natural incremental encoder receives positions and speeds of the first to sixth servomotors from the control unit, transfers positions and speeds to the first to sixth servomotors, and transmits positions and speeds of the first to sixth servomotors. Measuring the speed and outputting the pulse value to the control unit (S12) is performed.

Next, the controller determines whether the difference between the input pulse value and the output pulse value of the natural incremental encoder is greater than or equal to a preset reference value (S13).

Subsequently, when the difference between the input pulse value and the output pulse value of the natural increase type encoder is greater than or equal to the reference value, the controller stops the pulse input to the natural increase type encoder (S14).

Then, the control unit proceeds to set the position (S15) to the origin, the position that does not change any more for a predetermined time by continuing to lower the first to sixth actuator for a predetermined time.

In addition, the automatic initialization start (S11) and the automatic initialization end (S16) is a step indicating the start and end of the initialization method according to the present invention.

On the other hand, the naturally increasing type encoder may be modularized for convenient maintenance by being provided inside the servo motor or the control unit.

5 is a graph showing the variation of the pulse signal during the initialization process of the six-axis motion platform according to the present invention, by adding a special hardware by comparing the pulse value over time with the lowest position (D) and the reference value (S). You can automatically initialize the origin without having to.

11; Top plate 12; Bottom plate
13; Electric actuators 14; Servo motor
A; Neutral positions B, C, D; Lowest position
S; Reference value

Claims (3)

A lower plate of the motion platform, an upper plate of the motion platform positioned above the lower plate in isolation from the lower plate of the motion platform, first to sixth actuators for raising or lowering by electric force, and the first to sixth First to sixth servos installed in each actuator to supply electric power according to a control signal to the first to sixth actuators, and control signals for adjusting the height and inclination of the upper plate to the first to sixth servos. In the automatic initialization method of the 6-axis motion platform for a simulator using a control unit for transmitting to the motor and a natural incremental encoder,
The natural incremental encoder receives positions and speeds of the first to sixth servomotors from the control unit, transfers positions and speeds to the first to sixth servomotors, and transmits positions and speeds of the first to sixth servomotors. Measuring a speed and outputting the pulse value to the controller;
The control unit determines whether a difference between an input pulse value and an output pulse value of the natural incremental encoder is greater than or equal to a preset reference value;
Stopping the pulse input by the natural increase type encoder when a difference between an input pulse value and an output pulse value of the natural increase type encoder is greater than or equal to a reference value;
The control unit automatically initializes the six-axis motion platform for a simulator, including the step of setting the position of the first to sixth actuators that continue to descend for a predetermined time so that the position does not change anymore and does not change for a predetermined time to the origin. Way.
The method according to claim 1,
The natural increment type encoder is an automatic initialization method of a six-axis motion platform for a simulator, characterized in that provided in the servo motor.
The method according to claim 1 or 2,
The natural increment type encoder is an automatic initialization method of the six-axis motion platform for a simulator, characterized in that provided in the control unit.

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