JPS596403B2 - How to guide moving machines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for guiding a mobile machine, and more particularly, to a method for automatically driving a mobile machine by following landmarks discretely attached to a road surface. It is suitable for application to mobile machines and mobile machines that transport equipment in factories and hospitals.

When guiding a mobile machine using such landmarks that are discretely attached to the road surface, accurate running of the mobile machine along the landmarks is an important issue.

The present invention solves such problems and provides a guidance method that allows a moving machine or machine to travel accurately by following a predetermined landmark. By detecting the relative position of the mobile machine with respect to the marks, it travels while automatically correcting the error in the trajectory caused by traveling between marks, and also detects the run mark code and landmarks stored in the mobile machine. By checking with the map, we can determine whether the mobile machine is stopped or not on that landmark, the code of the landmark that should be the next target on the specified route, and the code required to proceed toward the next landmark. The vehicle is characterized in that it obtains information on the steering angle and the distance between marks to the next mark, and travels toward the next landmark by adjusting the amount of steering based on this information.

Hereinafter, a case where the method of the present invention is applied to a mobile machine that guides a blind person instead of a guide dog will be described with reference to the drawings. First, as shown in FIG.
Landmarks 2 for guidance are attached discretely along the planned travel route.

The landmarks 2 are formed with a certain width and length using, for example, paint or tape, and each landmark is given a unique code for identifying it. Now, when the mobile machine 1 approaches one landmark (code 109), the landmark sensor 3 installed at the front and rear of the mobile machine 1 operates to detect the landmark 2, and the center line of the landmark 2 and the front The deviation Δy from the center of the sensor 3 and the attitude angle Δψ of the machine with respect to the center line of the landmark are determined, and the traveling trajectory of the mobile machine 1 is
The steering angle θ given by the following equation is corrected to correctly follow the landmark.

θ=k1Δy+K2Δψ (Kl, k2 are constants) To explain more specifically, the right side of the above equation is the parameter Kl,
Indicates the amount by which a point in front of the moving machine on the center axis of the moving machine, which is determined by appropriately selecting k2, deviates from the course specified by the landmark (for example, the center axis of the landmark) .

This corresponds to the error that would occur after a certain period of travel if the steering angle was kept at 0 (straight ahead). Therefore, it is only necessary to provide a steering angle in proportion to this amount of deviation to steer the vehicle in a direction that reduces the deviation, that is, in a direction opposite to the deviation. By sequentially applying the steering angle in this way based on the results while detecting landmarks, deviation of the mobile machine from the course can be reduced and the mobile machine can be made to travel along the landmarks. As shown in FIG. 2, the landmark sensor 3 illuminates the landmark 2 with a fluorescent lamp 4, passes the reflected light through a light guide 6, increases the directivity, and then connects 16 sensors arranged in a line. The mark edge is detected from the differential output of two adjacent photo transistors as a set.
As shown in the figure, by amplifying the differential output, the influence of changes in the amount of light hitting the landmarks is reduced, and furthermore, the reference signal of the comparator is automatically adjusted in accordance with the amount of light.

According to the results of the simulation performed to determine the arrangement of the sensor 3 and the values of Kl and k2, k1=3, k2
= about 2 is appropriate, and the more sensors there are, the smoother the trajectory control is, and the closer the position is to the front of the machine, the more stable it is, but when considering economic efficiency and physical constraints, The number of phototransistors is 16, and two locations, one at the front and one at the rear of the mobile machine, are sufficient.

When the mobile machine 1 travels over the landmark 2 in this way, the trajectory is corrected based on the landmark, but at the same time the code of the landmark is detected by the sensor 3, and this code is transmitted to the mobile machine. The information necessary for following the next landmark is extracted by comparing it with the map related to the landmark stored in the map.

The above code does not necessarily have to be displayed as a number as shown in Figure 1. In order to make it easier to detect the code, for example, a figure corresponding to the code or a landmark may be displayed. A cutout corresponding to the code may be provided in a part so that the landmark sensor can detect it, or a plurality of magnets may be buried under the landmark so that the magnetic sensor can detect the arrangement as a code.

Also, give a code to each landmark virtually,
The virtual code may be used to read information from the map. For example, as shown in FIG.
Information such as non-stop status, next detected landmark code, steering angle required to travel to the next landmark, distance between marks, etc. is included in an appropriate format, and the above code "109" In this case, since it is an odd number code, "Non-stop" is selected on that landmark, the code of the next landmark to be followed is "106", and the way to proceed there is "Steering angle required for going straight j1". "stomach],
Information on the distance between landmarks [/] is read from the map, and the mobile machine 1 travels between the landmarks aiming at the next landmark "106" using a steering amount based on this information.

Then, when the mobile machine 1 travels to a place close to the distance "/", the landmark sensor 3 is activated, follows the next landmark, corrects the error in the trajectory caused by traveling between the landmarks, It reads the code [106] and stops at that position.

This is because the code "106" is an even number. When the blind person gives a command to, for example, ``turn right'' using the command grip, the mobile machine searches for the code ``106'' on the map and extracts the information corresponding to ``turn right.''

The information is that the code of the next landmark in the direction of "turn right" is "101", the steering angle is "m", the distance between U1 landmarks is "n", and the amount of steering based on that information is used to move the vehicle. The machine travels through the intersection in the commanded direction. Note that when the mobile machine first passes over a landmark, it extracts from the map the code of the next landmark to be detected on the specified route and the distance to that mark, so it can only detect the above distance. It is not necessarily necessary to read the codes of landmarks detected when driving, and it is possible to read the codes for confirmation, but continue guided driving assuming that the landmarks have the codes extracted from the map. can be done.

By repeating these operations, you can freely move to any location, but when driving through a dead end or an intersection where the road is more diverse than a crossroads, you can take the following measures, for example. .

In other words, if there is no road in the direction you are trying to proceed, the code of the landmark in the foreground is set to "O" to detect it, and the blind person is informed of this and waits for new instructions. If there are many branches,
The code of the landmark at the entrance of the intersection is set as a negative code, and by searching for the code of the absolute value of that code, the code of the true destination is obtained and the route is followed.

For example, when a "left turn" is commanded at a landmark with code "134," the part of the map code "134" that corresponds to "left turn" is "-500N," so the mobile machine recognizes that this intersection is an N intersection. (N = 6 in the figure) is notified to the blind person by electrical stimulation, etc., and after waiting for an instruction from the blind person, the robot immediately moves on to searching for the code "500".

A second command from the blind person is given by the command switch in the form of ``turn left'' if the direction to go is the first one counting from the left, ``go straight'' if the path is the second, and ``turn right'' if the path is the third. If the command "go straight" is given, the code "1" corresponding to "go straight" in code "500" is given.
31 landmarks as the target, the steering angle “γ
], proceeding with the inter-landmark distance “δ”. Next, the principle of guiding a mobile machine using the above-mentioned landmarks will be briefly explained with reference to the block diagram shown in FIG.

Landmark information from the landmark sensor in the guidance subsystem enters the central subsystem through the preprocessing device, and is compared with the map in the guidance information processing device in the comprehensive judgment device in the central subsystem to determine the necessary information in the map. This information is taken out, and together with information from the position recognition device, a comprehensive judgment necessary for traveling is made in the comprehensive judgment device, and the steering angle and speed command value are sent to the movement control device.

The steering and speed controllers in the travel direction control subsystem provide a commanded steering angle and commanded speed so that the mobile machine is provided with proper steering and accurately travels on a trajectory along the landmarks. I will do it. In that case, information from the mobile machine such as stopping at an intersection etc. is transmitted from the central subsystem to the blind person via the communication device of the communication subsystem, and conversely, commands from the blind person are sent to the blind person via the command processing device for comprehensive judgment. communicated to the device and the movement controller.
In this way, a mobile machine can be made to travel along a planned route by giving the necessary commands each time it stops at an intersection, but by memorizing the route in advance, it is possible to You can also automatically search for and run the route by simply giving the code.

As detailed above, according to the method of the present invention, when a mobile machine travels over a landmark, by detecting the relative position to the landmark, the trajectory error caused by traveling between the marks is corrected. It travels while automatically correcting itself, and when it passes the landmark, it reads out the necessary information by comparing the code with the map related to the landmark, and then moves to the next landmark based on the amount of steering based on this information. Since the mobile machine is designed to drive with the aim of reaching the target, it is only necessary to discretely attach simple landmarks to the road surface on which the mobile machine is traveling, and all other information necessary for travel guidance is retained as a map on the mobile machine. This can significantly reduce equipment costs, and since the mobile machine has the above-mentioned map, it is not necessarily necessary to give the travel route as a sequence; for example, the required route can be determined by simple operations such as giving the start point and end point codes. It is possible to make the vehicle run along the following lines.

[Brief explanation of drawings]

Fig. 1 is a conceptual diagram of guidance using landmarks in the method of the present invention, Fig. 2 is a configuration diagram of a landmark sensor, and Fig. 3
FIG. 4 is a block diagram of a mark detection circuit for explaining the principle of detecting landmarks, FIG. 4 is an explanatory diagram showing an example of a map, and FIG. 5 is a block diagram for explaining the concept of information processing. 1...Moving machine, 2...Landma Kazuhisa 3...Landmark sensor.

Claims (1)

[Claims] 1 Landmarks with unique codes and fixed widths and lengths are attached discretely along the travel route to the main parts of the passage, mainly intersections, so that mobile machines can travel on the landmarks. When doing so, a sensor detects the relative position of the machine to the landmark, and by steering the machine accordingly, it automatically runs on a trajectory that follows the landmark, and also automatically tracks the landmark's code. By comparing it with a map related to landmarks stored in the mobile machine, it is possible to determine whether the mobile machine is stopped or not on that landmark, the code of the landmark that should be the next target on the specified route, and the next landmark. Information on the steering angle required to proceed toward a landmark and the distance between marks to the next mark is extracted from the above map, and the vehicle travels between landmarks through steering control based on these information. A method for guiding a mobile machine, characterized in that the mobile machine is guided to travel by.