JPH02300803A - Unmanned mobile body - Google Patents

Abstract

PURPOSE:To evade an obstruction in a short time and smoothly by detecting the position and width of the obstruction in the advancing direction of a vehicle, and finding a course to evade the obstruction by comparing them with a travel course stored in a memory means. CONSTITUTION:When the position of the obstruction 88 i.e. a distance from the vehicle to the obstruction 88, and the size of the obstruction 88 i.e. the width of it are detected, a CPU 62 compares the travel course stored in the memory means 64 with the position and the width of the obstruction 88, and finds the optimum course to evade the obstruction 88. For example, such control that the vehicle can evade the obstruction 88 passing the left side when it is judged that the vehicle comes off the travel course by evading the obstruction 88 passing the right side and furthermore, the vehicle can be introduced to an original travel course is performed. Also, when it is judged that it is impossible to evade the obstruction 88 even by passing both the right and left sides, the vehicle is stopped and stands by. In such a way, travel can be continued as evading the obstruction smoothly.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is an unmanned vehicle that travels according to a pre-stored travel course, and when an obstacle that enters the travel course is detected, it travels unmanned while avoiding the obstacle. It's about the body.

(Background of the Invention) It has been proposed to cause a moving object such as a golf cart to travel unmanned according to a pre-stored travel course. For example, there is a system that monitors the running direction and amount of movement of the vehicle body to determine the vehicle body position, and then runs the vehicle unmanned according to the pre-stored running course and running conditions. In such an unmanned vehicle that travels along a pre-stored travel course, it is necessary that if an unexpected obstacle enters the course, the vehicle can avoid the obstacle.

Therefore, it has been proposed to install multiple obstacle sensors at the front of the vehicle body that monitor different ranges in the width direction of the vehicle body, and avoid obstacles by steering in the direction of the sensor that has not detected an obstacle (for example, (Sho 62-88006). However, in this method, there may be a case where the steering maneuver to avoid an obstacle causes the vehicle to approach another obstacle such as a wall. In this case, only after this wall is detected does it become clear that the avoidance direction for the previously detected obstacle was inappropriate, which necessitates complicated maneuvers such as stopping and backing up. Sometimes it took a long time to avoid obstacles, or it became difficult or impossible to drive.

(Objective of the Invention) The present invention has been made in view of the above circumstances, and it is an object of the present invention to determine an appropriate avoidance direction as quickly as possible when avoiding an obstacle, and to enable smooth running while avoiding the obstacle. The purpose is to provide an unmanned mobile vehicle.

(Structure of the Invention) According to the present invention, this object includes: a traveling direction detecting means for determining the traveling direction; a moving amount detecting means for determining the amount of movement; and determining the position of the vehicle body by monitoring the traveling direction and the amount of movement. Obstacle detection means for detecting the position and width of an obstacle in the forward direction of the vehicle body in an unmanned moving body that is equipped with a position determining means and a memory means for storing a predetermined running course, and runs unmanned according to the running course; This is achieved by an unmanned moving body characterized by comprising: course determining means for determining a course to avoid the obstacle by comparing the position and width of the obstacle with a traveling course stored in the memory means. .

(Embodiment) FIG. 1 is a functional block diagram showing the configuration of an embodiment of the present invention, FIG. 2 is a block diagram showing a control system of a moving object, and FIG. 3 is a side view of a golf cart as a moving object. FIG. 4 is a functional block diagram showing the configuration of the obstacle detection means, and FIG. 5 is a flowchart of the operation.

In FIG. 3, reference numeral 10 indicates a vehicle body frame, 12 (12a
, 12b) are a pair of left and right rear wheels, and 14 is one steering front wheel. The vehicle body frame IO has an upper frame loa that stands up from between the rear wheels 12 and whose upper end extends horizontally forward. The rotation of the electric drive motor 16 is transmitted to the rear wheels 12 via a chain 18, 20 and a differential gear 22.The amount of rotation of the left and right rear wheels 12a, 12b is determined by a pair of left and right encoders 24 (24a, 24b). detected separately. The front wheel 14 is attached to the lower end of a steering shaft 28 held in a steering shaft cylinder 26. A steering motor 32 is connected to the upper end of the steering shaft 28 via a clutch 30, and rotation of a handle shaft 36 is transmitted through a link 34. That is, by engaging and disengaging the clutch 30, the front wheels 14 are selectively steered by the motor 32 during automatic travel and by the handlebar 38 during manual travel.

40 is a controller and each motor 1 for driving and steering
6.32, it has a circuit for power control, an interface, etc. 42 is a lead-acid battery mounted at the bottom near the center of the vehicle body, and a flat plate 4 covering the top of this battery 42
A golf bag is placed on the upper frame 10a so as to lean against the upper frame 10a from the left and right sides. car body frame lO
A step 46 is provided protruding from the rear of the vehicle for the driver to stand on. The driver stands at this step 46 as necessary and operates the input device 48, main switch 50, and steering wheel 38.
etc. can be operated.

Next, the CPU device 60 will be explained. This CPU device 60 includes a CPL'62 consisting of a digital computer, a semiconductor memory means 64, and a pulse counter 66 (66a, 66b).
), etc., the one-wheel pulse counter 66 is connected to the left and right rear wheels 12.
Pulses output by the encoder 24 as the encoder 24 rotates are counted separately. The count values of these counters 66 are
The data is read into the CPU 62 via an interface (not shown) provided in the controller 40. The memory 64 has C
In addition to the operation program of PU62, the planned driving course,
Data indicating running conditions such as running speed and stopping position are stored in advance. - The CPU 62 sequentially and repeatedly performs the calculations of the functions shown in FIG. 1 according to the program stored in the memory 64. First, the CPU 62 sends a signal to the controller 40 to drive the steering motor 32 and the travel motor 16 according to the planned travel route stored in the memory 64.

As a result, the front wheels 14 are steered, the rear wheels 12 are driven, and the vehicle travels on its own in accordance with the set conditions approximately along the planned travel route. C
The PU 62 separately determines the amount of rotation of the left and right rear wheels 12a, 12b from the counts and values of the wheels 6a, 66b while the vehicle is running. That is, in this embodiment, the CPU
62, together with the left and right encoders 24 and the counter 66, indicates the rotation of the left and right rear wheels 12 ffi a + 11! (a-b
) is formed as a running direction change detection means 68 (FIG. 1) for detecting a change α in the running direction. Further, the CPU 62, together with the encoder 24 and the counter 66, controls both rotation amounts a,
A moving amount detecting means 70 is formed to determine the moving amount e by the average (a+b)/2 of b. These changes α in the traveling direction and the amount of movement are the appropriate positions (sampling points) while traveling.
are integrated by integrating means 72 and 74, and by using these integrated values Σα and Σa, the position of the moving object is determined by position determining means 76. That is, since the direction and amount of movement of the vehicle body from the sampling point are determined, the position of the vehicle body can be determined.

Note that the error in the vehicle body position determined in this manner gradually increases due to the accumulation of position detection errors.

Therefore, it is desirable to correct this error at an appropriate position.

For example, while an i-norther light emitter/receiver is provided on the moving object, reflectors such as corner cubes whose relative positions are known are appropriately provided around the driving course, and the vehicle body position can be detected using these. . In other words, the directions of three reflectors whose positions are known are detected at three consecutive positions,
The position of the moving object is determined by monitoring the direction and amount of movement between three positions, and this method is disclosed in Japanese Patent Application No. 315172/1983.

It is desirable to correct the position using such an appropriate method.

Next, the obstacle detection means 80 will be explained. In this embodiment, the obstacle detection means 80 includes several if sensors 82 (for example, seven sensors) arranged at equal intervals in the width direction of the vehicle body at the front of the vehicle body.
82a=g), the controller 84, and the comparator 8
6. The sensor 82 includes, for example, an emitter of ultrasonic waves or light that is emitted in a range of angles where the emission angle is small and does not overlap with each other, and a receiver that detects the ultrasonic waves or light reflected by hitting an obstacle. The transmitters of each sensor 82 may emit ultrasonic waves or light with a time difference from each other. The controller 84 sends a drive signal to each sensor 82 to control the emission timing of ultrasonic waves and light. The comparator 86 determines the distance to the obstacle by dividing it into a plurality of ranges by detecting ultrasonic waves and light reflected by the obstacle. For example, by determining the time difference and change in intensity between the emission and reception of reflected ultrasonic waves or light, and comparing these time differences and intensity changes with predetermined values, the distance to the obstacle can be determined, for example, from far, medium, or near. It is determined in three stages. The comparison result of the comparator 86 is input to the CPU 62, where the position and size of the obstacle is determined.

For example, as shown in FIG. 4, if an obstacle 88 exists at a middle distance in front of the sensors 82b, c, d, this obstacle 88 will be detected by the sensors 82b, c, d.

The comparator 86 determines that the distance to the obstacle is intermediate or long based on the time difference and intensity change of the ultrasonic waves and light reflected by the obstacle 88. Using this result, the CPU 62 reconstructs the following map in the memory, with the range where the obstacle 88 exists as 1 and the position where there is no obstacle as O.

That is, as shown in FIG. 5, whether any of the sensors 82 detects an obstacle 88 at a short distance (step 100);
When detected at a medium distance (step 1.02) or at a long distance (step 104), the CPU 62 calculates the position and size of the obstacle 88 based on the output of the comparator 86 using this map (step 1.02). 106).

When the position of the obstacle 88, that is, the distance from the vehicle body to the obstacle 88, and the thickness or width of the obstacle 88 are detected in this way, the CPU 62 selects the driving course stored in the memory means 64. The positions and widths of these obstacles 88 are compared to determine the optimal course to avoid the obstacles 88. This calculation is performed by the course determining means 90 (FIG. 1) of the CPU 62 as follows. That is, the course determining means 90 recognizes and confirms the relative positional relationship between the travel course and the vehicle body position (step 108), and selects a method for avoiding the obstacle 88 (step 110). For example, if it is determined that avoiding to the right side of the obstacle 88 will take the vehicle out of the running course, control is performed to avoid the obstacle 88 to the left side (step 112), and further control is performed to guide the vehicle to the original running course. (step 114). If it is determined that the obstacle 88 cannot be avoided by avoiding the obstacle 88 to the right or to the left, the vehicle body is controlled to stop and stand by (step 116).

In the above embodiment, the obstacle detection means 80 has a plurality of sensors 82, but the present invention has a sensor consisting of a transmitter and a receiver that rotates in the horizontal direction.
It is also possible to detect obstacles. Furthermore, if the sensor determines the distance to the obstacle by limiting it to three ranges as in this embodiment, the configuration of the comparator 86 becomes very simple, but in the present invention, the distance to the obstacle is divided into more ranges and the distance is determined. Of course, the distance may be determined in detail or the distance may be determined continuously.

(Effects of the Invention) As described above, the present invention determines the traveling direction and amount of movement of the vehicle body and monitors the traveling position, and also detects the position and width of the obstacle in the forward direction of the vehicle body, and detects the position and width of the obstacle in the forward direction of the vehicle body. This method determines a course to avoid an obstacle by comparing the width and width with the driving course stored in the memory means. Therefore, when an obstacle is detected, it is possible to determine in which direction to avoid the obstacle. The optimality can be determined from the relationship with the running course, and obstacles can be avoided quickly and smoothly.

[Brief explanation of the drawing]

Fig. 1 is a functional block diagram showing the configuration of an embodiment of the present invention, Fig. 2 is a block diagram showing a control system of a moving body, Fig. 3 is a side view of a golf cart as a moving body, and Fig. 4 is a block diagram showing the configuration of an embodiment of the present invention. FIG. 5 is a functional block diagram showing the configuration of the obstacle detection means, and is a flowchart of the operation. 62... CPU, 64... Memory means, 68... Running direction change detection means. 70... Movement amount detection means, 76... Position determination means, 80... Obstacle detection means, 88... Obstacle, 90... Course determination means.

Claims (1)

[Scope of Claims] A traveling direction detecting means for determining the traveling direction, a moving amount detecting means for determining the amount of movement, a position determining means for determining the position of the vehicle body by monitoring the traveling direction and the amount of movement, An unmanned moving body that is equipped with a memory means for storing a course and runs unmanned according to the traveling course, an obstacle detection means for detecting the position and width of an obstacle in the forward direction of the vehicle body, and an obstacle detection means for detecting the position and width of the obstacle in the forward direction of the vehicle body An unmanned moving body characterized by comprising: course determining means for determining a course for avoiding the obstacle by comparing the traveling course stored in the memory means.