Unmanned following vehicle

1. An unmanned following vehicle comprising:

a controller configured to control the unmanned following vehicle to move in parallel with a moving object by following the moving object on a left side or a right side of the moving object, wherein

the controller is configured to control the unmanned following vehicle to move in parallel with the moving object by:

the controller being configured to adjust a moving speed of the unmanned following vehicle according to a Y-axis coordinate difference value, which is a difference value between a position of the moving object and a position of the unmanned following vehicle in a forward direction, and

the controller being configured to adjust a steering direction and a steering angle of the unmanned following vehicle according to an X-axis coordinate difference value, which is a difference value between the position of the moving object and the position of the unmanned following vehicle in a lateral direction,

wherein the controller is further configured to:

control the unmanned following vehicle to follow the moving object only while the X-axis coordinate difference value is greater than a first reference value and less than a second reference value,

based on the X-axis coordinate difference value being changed from being less than or equal to the first reference value to being greater than the first reference value, such that the X-axis coordinate difference value is greater than the first reference value for a first time period longer than a first reference time period, control the unmanned following vehicle to start following the moving object,

based on the X-axis coordinate difference value being changed from being greater than the first reference value to being less than or equal to the first reference value, such that the X-axis coordinate difference value is less than or equal to the first reference value for a second time period longer than a second reference time period, control the unmanned following vehicle to stop following the moving object,

based on the X-axis coordinate difference value being changed from being greater than or equal to the second reference value to being less than the second reference value, such that the X-axis coordinate difference value is less than the second reference value for a third time period longer than a third reference time period, control the unmanned following vehicle to start following the moving object, and

based on the X-axis coordinate difference value being changed from being less than the second reference value to being equal to or greater than the second reference value, such that the X-axis coordinate difference value is equal to or greater than the second reference value for a fourth time period longer than a fourth reference time period, control the unmanned following vehicle to stop following the moving object.

2. An unmanned following vehicle comprising:

a controller configured to control the unmanned following vehicle to move in parallel with a moving object by following the moving object on a left side or a right side of the moving object, wherein

the controller is configured to control the unmanned following vehicle to move in parallel with the moving object by:

the controller being configured to adjust a moving speed of the unmanned following vehicle according to a Y-axis coordinate difference value, which is a difference value between a position of the moving object and a position of the unmanned following vehicle in a forward direction, and

the controller being configured to adjust a steering direction and a steering angle of the unmanned following vehicle according to an X-axis coordinate difference value, which is a difference value between the position of the moving object and the position of the unmanned following vehicle in a lateral direction,

wherein the controller is further configured to:

control the unmanned following vehicle to follow the moving object only while the X-axis coordinate difference value is greater than a first reference value and less than a second reference value,

set a third reference value to be greater than the first reference value,

set a fourth reference value to be greater than the third reference value and less than the second reference value,

control the unmanned following vehicle to move forward or backward based on the X-axis coordinate difference value being greater than the third reference value and less than the fourth reference value, and

control the unmanned following vehicle to make a left turn or a right turn toward a moving direction of the moving object based on the X-axis coordinate difference value being greater than the first reference value and less than the third reference value, or based on the X-axis coordinate difference value being greater than or equal to the fourth reference value and less than the second reference value.

3. The unmanned following vehicle of claim 2 , wherein in a case where the unmanned following vehicle follows the moving object from the left side of the moving object, the controller is configured to:

based on the X-axis coordinate difference value being greater than the first reference value and less than or equal to the third reference value, increase an angle of the left turn as the X-axis coordinate difference value becomes smaller, and

based on the X-axis coordinate difference value being greater than or equal to the fourth reference value and less than the second reference value, increase an angle of the right turn as the X-axis coordinate difference value becomes larger.

4. The unmanned following vehicle of claim 2 , in a case where the unmanned following vehicle follows the moving object from the right side of the moving object, the controller is configured to:

based on the X-axis coordinate difference value being greater than the first reference value and less than or equal to the third reference value, increase an angle of the right turn as the X-axis coordinate difference value becomes smaller, and

based on the X-axis coordinate difference value being greater than or equal to the fourth reference value and less than the second reference value, increase an angle of the left turn as the X-axis coordinate difference value becomes larger.

5. An unmanned following vehicle comprising:

a controller configured to control the unmanned following vehicle to move in parallel with a moving object by following the moving object on a left side or a right side of the moving object,

wherein the controller is configured to control the unmanned following vehicle to move in parallel with the moving object by:

the controller being configured to adjust a moving speed of the unmanned following vehicle according to a Y-axis coordinate difference value, which is a difference value between a position of the moving object and a position of the unmanned following vehicle in a forward direction, and

the controller being configured to adjust a steering direction and a steering angle of the unmanned following vehicle according to an X-axis coordinate difference value, which is a difference value between the position of the moving object and the position of the unmanned following vehicle in a lateral direction,

wherein the unmanned following vehicle further comprises:

a rotary reel configured to elastically provide a string connected to the moving object,

a first encoder configured to measure a length of the string, as the X-axis coordinate difference value, while rotating along with the rotary reel;

a second encoder configured to measure a horizontal angle of the string, as the Y-axis coordinate difference value, while rotating according to a change in a horizontal position of the string connected to the moving object; and

a third encoder configured to measure a vertical angle of the string as a Z-axis coordinate difference value, which is a difference value between the position of the moving object and the position of the unmanned following vehicle in a vertical direction, while rotating according to a change in a vertical position of the string connected to the moving object,

wherein the controller is further configured to:

control movement of the unmanned following vehicle according to measurement results of the first encoder, the second encoder, and the third encoder,

adjust a distance between the moving object and the unmanned following vehicle according to whether the Z-axis coordinate difference value is changed,

based on the horizontal angle of the string being positive, in the forward direction, and an absolute value thereof being greater than a first reference value, the controller is further configured to perform forward moving control, and

based on the horizontal angle of the string being negative, in a backward direction, and an absolute value thereof being greater than a second reference value, the controller is further configured to perform backward moving control.