JP5105595B2 - Travel route determination map creation device and travel route determination map creation method for autonomous mobile body - Google Patents

Description

  The present invention relates to a travel route determination map creation device and a travel route determination map creation method for an autonomous travel mobile body used to determine the travel route of a mobile body traveling autonomously.

As the above-described autonomous traveling mobile body, for example, there are traveling robots that carry out operations such as transportation in factories and hospitals, security in the outdoors around the facility, and humanoid robots that support human activities.
In order to realize autonomous traveling in these robots, it is necessary to create a map for determining a moving route. Conventionally, external information obtained by external measuring means such as a plurality of sensors and dead reckoning are used. A map for determining a travel route based on the self-location information obtained by such means as described above is created (see, for example, Patent Documents 1 to 4).

However, none of the above-described traveling robots or humanoid robots are suitable for high-speed autonomous traveling because they are not premised on high-speed autonomous movement.
2. Description of the Related Art In recent years, research and development of a mobile body equipped with a large number of external measuring means such as a laser range finder and a millimeter wave radar has been promoted as a mobile body that autonomously travels at high speed (see, for example, Non-Patent Document 1).
JP 07-306042 Japanese Patent Laid-Open No. 10-260724 JP2004-298975 JP 2007-041656 Rough Terrain Autonomous Mobility Part2: An Active Vision, Predictive Control Approach Alonzo Kelly and Anthony Stentz Robotics Institute, Carnegie Mellon University, Pittsburgh, PA15213

  In order to allow the above-mentioned moving body to perform high-speed autonomous traveling, it is necessary to continuously create a consistent map suitable for traveling control with less delay time based on the external environment information obtained by the external measurement means. However, external information obtained by a large number of external measurement means is generally acquired at different rates, asynchronously, and with different delay times, so it is measured at different locations during high-speed movement. Data.

Therefore, in the continuous creation of a consistent map based on the outside world information obtained by these outside world measuring means, it has been a conventional problem how to compensate for the delay required for processing the outside world information. .
The present invention has been made paying attention to the above-described conventional problems, and can compensate for the delay required for processing the outside world information obtained by a large number of outside world measuring means, and as a result, is suitable for high-speed autonomous driving. An object of the present invention is to provide a travel route determination map creation device and a travel route determination map creation method for an autonomous mobile vehicle that can stably create a travel route determination map.

The invention according to claim 1 of the present invention is a device for creating a map (map of about 100 m square in the vicinity of a moving body) used to determine the traveling route of a moving body that autonomously travels at a high speed (approximately 50 km / h). In addition, a sensor such as a laser range finder is provided to measure the presence or absence of an obstacle from the vicinity of the moving body to a distance, and self-position measurement for determining the self-position of the moving body by means such as dead reckoning. And a sensor coordinate system outside world data obtained by the outside world measurement unit, a time stamp is attached to determine the runnable area and the inability to run due to obstacles, and the ground coordinate system obtained by the self-position measurement unit ( A data analysis unit that generates a self-position estimation result by attaching a time stamp to the self-position data, and the data analysis Comprises a ring buffer for storing in chronological sensor coordinate system external data and the ground coordinate system location data with a time stamp obtained from the ring buffer every time the latest sensor coordinate system external data is measured Various data at an arbitrary time at or near the latest is taken out from the position, the position of the moving body at that time is recognized, coordinate conversion to the ground coordinate system is performed, and the latest sensor coordinate system external data is sequentially reflected. A map creation module for creating a ring buffer-like base map having a spatial two-dimensional periodic boundary condition; and, based on the base map created by the map creation module, A map creation unit having a travel route determination module for deciding, and the map creation module of the map creation unit is capable of traveling Considering the length of the route determination processing time by the travel route determination module at the stage where a request for a local map required to determine the travel route of the moving body toward the area is issued from the travel route determination module, It is characterized in that it is configured to cut out from the base map a local map facing the required direction starting from the position where the mobile body arrives during this route determination processing time, and send it to the travel route determination module, The configuration of the travel route determination map creation device for the autonomous mobile body is used as means for solving the above-described conventional problems.

In this case, for example, a laser range finder or a stereo camera can be used as an external measurement unit that measures the presence or absence of obstacles from the vicinity of the moving object to a distant place, but each sensor is subject to performance limitations. It is desirable to combine multiple sensors with different characteristics (ranges and methods).
Specifically, although the distance and shape information can be obtained directly, the laser range finder suitable for obtaining near-field information due to the low measurement rate, stereo vision suitable for obtaining wide-angle information although it is inferior in accuracy, It is desirable to combine image processing such as texture for identifying attributes.

  On the other hand, for example, dead reckoning or GPS (Global Positioning System) can be used as the self-position measuring unit that obtains the self-position of the moving body and clarifies the measurement point by the external measurement unit. Dead reckoning, in particular, cannot obtain absolute position accuracy due to drift in the yaw direction, but has high continuity. On the other hand, in the GPS, a discontinuous portion of about several meters is generated except when an expensive RTK-GPS (Real Time Kinematic GPS) is used.

Local maps, such as the travel route determination map for autonomously moving vehicles, require relative position accuracy between the moving object and the outside world rather than absolute position accuracy. Highly continuous data that can be obtained is desirable.
At this time, self-position data obtained from dead reckoning data and GPS data can be used in combination, and continuous and absolute position self-position data can be estimated using an infinite impulse response filter such as a Kalman filter. It is.

When a plurality of sensors having different characteristics are combined in the above-described external measurement unit, the data acquired by these sensors are all sensor coordinate system external data, and these data include the update rate and the data processing delay time. Because they are different, it is necessary to ensure consistency when creating a single map.
On the other hand, the data acquired by the self-position measuring unit is the ground coordinate system self-position data, and this data is acquired asynchronously and at a different rate from the sensor coordinate system external data, so it matches the sensor coordinate system external data. It is necessary to take sex.

  In the travel route determination map creation device of the autonomous mobile body of the present invention, the sensor coordinate system external data acquired asynchronously by the external measurement unit and the ground coordinate system self-position data acquired asynchronously by the self-position measurement unit In addition, the data analysis unit correctly manages when and where the data was acquired while traveling by attaching high-accuracy (less than 1 msec) time stamps. To create a base map.

The map creation unit manages the base map in the ground coordinate system, and when determining the travel route in the travel route determination module, by specifying the position in the ground coordinate system and the required direction, And an accurate relative map of the required direction.
In the map creation module of the map creation unit, even if there is a change in the position of the moving body and the heading direction during the route determination process by the travel route determination module, Even if there is a change in position and advancing direction, a local map that estimates the position where the mobile body arrives when control is actually started and faces the required direction from this arrival position Is cut from the base map and sent to the travel route determination module, so that the travel route can be determined and controlled using an accurate relative map from the moving body.

Further, in the travel route determination map creation device for an autonomous travel mobile body according to the present invention, the map creation unit accumulates time-stamped sensor coordinate system external data and ground coordinate system self-position data in time series. By using a time-series direction ring buffer, it becomes possible to access data at an arbitrary time near the latest data with respect to already acquired data, and a spatial direction ring buffer is used. By adopting a two-dimensional periodic boundary condition as the data structure of the base map, an endless track can be created, and the base map of the ground coordinate system can be continuously held when continuously running.

On the other hand, the invention according to claim 2 of the present invention is a map creation method used to determine the travel route of a mobile body that travels autonomously, and is distant from the vicinity of the mobile body by a sensor such as a laser range finder. In addition to measuring the presence or absence of obstacles, the self-position of the moving body is obtained by means such as dead reckoning, and the sensor coordinate system external world data obtained by the sensor is attached with a time stamp, and the vehicle cannot travel due to obstacles and obstacles. Performs region determination processing, generates a self-position estimation result by attaching a time stamp to the ground coordinate system self-position data obtained by means such as dead reckoning, and subsequently follows the sensor coordinates with the time stamp. accumulated in the ring buffer along system external data and the ground coordinate system location data in time series, a total of the latest sensor coordinate system external data From the ring buffer each time retrieves various data at any time of the most recent or in the vicinity thereof, by performing a coordinate transformation to the earth coordinate system to recognize the position of the mobile at that time, the latest of the sensor coordinate system outside A ring buffer-like base map having a spatial two-dimensional periodic boundary condition that sequentially reflects data is created, and a travel route of the moving body toward the travelable region is determined based on the ring buffer-like base map. In consideration of the length of time required to determine the travel route in the step of obtaining a local map necessary for the vehicle, it is necessary to start from the position where the moving body reaches within the travel route determination processing time. A portion facing the direction is cut out from the base map to form a local map necessary for determining the travel route.

  In this map generation method for determining a travel route of an autonomous mobile body, high accuracy (less than 1 msec) is obtained for sensor coordinate system external data acquired asynchronously and ground coordinate system self-position data acquired asynchronously in the same manner. It is possible to create a single consistent base map by correctly managing when and where the data is acquired while traveling by attaching each time stamp.

The above-mentioned base map is managed in the ground coordinate system, and when determining the travel route, by specifying the position in the ground coordinate system and the required direction, an accurate relative map of the position and the required direction can be obtained. It has become.
Even if a change in the position and advancing direction of the moving object occurs during the travel route determination process, that is, a change in the position and advancing direction of the moving object occurs within the travel route determination control cycle. Even if it is a case, the position where the moving body arrives at the time when the control is actually started is estimated, and the part facing the necessary direction starting from this arrival position is cut out from the base map to Since a local map necessary for determination is used, it is possible to determine and control a travel route using an accurate relative map from a moving object.

Further, the travel route determination mapping method autonomous moving body of the present invention, accumulated in the ring buffer along the sensor coordinate system external data and the ground coordinate system location data with timestamps in a time series, the latest Each time the sensor coordinate system outside world data is measured, various data at the latest time or in the vicinity thereof are extracted from the ring buffer , the position of the moving object at that time is recognized, and the coordinate conversion to the ground coordinate system is performed. the has the most current configuration to create a ring buffer-shaped base map having successively reflecting the spatial two-dimensional periodic boundary condition sensor coordinate system external data, with such a configuration, the track The base map of the ground coordinate system can be continuously held when the vehicle continuously runs.

Since the travel route determination map creation device for the autonomous mobile body according to claim 1 and the travel route determination map creation method for the autonomous mobile body according to claim 2 have the above-described configurations, It is possible to compensate for the delay required for processing the outside world information and determining the route, and thus it is possible to stably create a route determination map suitable for high-speed autonomous driving. A very excellent effect is achieved that stable traveling control is possible.

Continuous addition, in the autonomous moving body in the travel path determination map creation method according to the autonomous moving body travel path determination map creation device and claim 2 of according to claim 1 of the present invention, even in the memory of finite A very good effect is that it is possible to hold a map in an automatic manner.

Hereinafter, a travel route determination map creation device and a travel route determination map creation method for an autonomous mobile body according to the present invention will be described with reference to the drawings.
FIGS. 1-6 has shown one Embodiment of the map creation apparatus for the traveling route determination of the autonomous traveling mobile body which concerns on this invention, In this embodiment, the case where an autonomous traveling mobile body is an autonomous traveling vehicle is shown as an example. Will be described.

  As shown in FIGS. 1 and 2, this travel route determination map creation device 1 includes a laser range finder 11 for acquiring short-range information, a stereo camera 12 suitable for acquiring wide-angle information, and other sensors 13. And the outside measurement unit 10 for measuring the presence or absence of a fault from the vicinity of the autonomous vehicle C to the distance, the wheel odometer 21, the yaw rate sensor 22 and the GPS 23 for dead reckoning, The self-position measuring unit 20 for obtaining the position, the sensor coordinate system external data obtained by the external measuring unit 10 and the ground coordinate system obtained by the self-position measuring unit 20 (coordinates having the origin and the position and direction where the autonomous vehicle C is started) System) A data analysis unit 30 to which self-location data is input via the input / output circuit 2 and a map creation unit 40 connected to the data analysis unit 30 via the LAN 3 are provided. Eteiru.

In this case, the external measurement unit 10 is mounted on the front end (the left end in FIG. 2) of the autonomous vehicle C, while the self-position measurement unit 20 together with the data analysis unit 30, the map creation unit 40, and a vehicle body control unit 60 described later. It is mounted at the rear end portion (right end portion in FIG. 2) of the autonomous traveling vehicle C, and an antenna 24 for the GPS 23 is disposed at the rear end portion of the autonomous traveling vehicle C.
The steering means 51 of the vehicle body drive unit 50 in the autonomous vehicle C is connected to the vehicle body control unit 60 via the driver 52 and the input / output circuit 4, and the vehicle speed control means 53 of the vehicle body drive unit 50 is a converter. 54 and the input / output circuit 4 are connected to the vehicle body control unit 60, and a control signal from the map creation unit 40 is input to the vehicle body control unit 60 via the LAN 3.

  As shown in FIG. 3, the data analysis unit 30 attaches a time stamp of less than 1 msec to sensor coordinate system external data such as distance data obtained by the external measurement unit 10, and a travelable region and a travel impossible region due to a fault. In addition to the obstacle detection module 30A for performing the determination process, a self-position estimation result is generated by similarly attaching a time stamp to the ground coordinate system self-position data based on the vehicle speed, yaw rate, etc. obtained by the self-position measurement unit 20. Self-location information generating module 30B.

The map creation unit 40 has a map creation module 40A for creating a base map based on time stamps attached to various data obtained from the data analysis unit 30, and the map creation module 40A. The travel route determination module 40B that determines the travel route of the autonomous vehicle C is provided based on the base map created in (1).
In this embodiment, the map creation module 40A of the map creation unit 40 includes, as shown in FIG. 4, sensor coordinate system external data (laser range finder data 11a, image processing data 12a) with a time stamp obtained from the data analysis unit 30. , Other sensor data 13 a) and ground coordinate system self-position data 21 a are stored in ring buffers 31 to 34 that accumulate in time series.

  In this mapping module 40A, as shown in FIG. 5, the latest ground coordinate system self-position data 21a1 is taken out from the self-position data ring buffer 34, and the past sensor coordinate system outside world from the time stamp of the self-position data 21a1. Search for data 11a1, 12a1 (other sensor data 13a is omitted in FIG. 5), search for ground coordinate system self-position data 21a2, 21a3 closest to the time stamp of past sensor coordinate system external data 11a1, 12a1, Is reflected in the correct ground coordinate system position of the base map.

  That is, each time the latest sensor coordinate system external data 11a1, 12a1 is measured, the position of the autonomous vehicle C at that time is recognized and coordinate conversion to the ground coordinate system is performed, so that the latest sensor coordinate system external data 11a1 is obtained. , 12a1 are sequentially reflected to create a consistent base map. In addition, the code | symbol X of FIG. 5 has shown the update amount per said search, and the code | symbol Y has shown the last map update position.

  In this map creation module 40A, since the data structure of the base map is a spatial two-dimensional periodic boundary condition, the autonomous vehicle C moves after using these data once as conceptually shown in FIG. Then, since the data at the same point is used again, it is necessary to initialize the continuous area. Specifically, on the base map, in addition to the area where the map update is effective, a margin greater than the movement distance of the autonomous vehicle C within the map update cycle is provided, and the area corresponding to the opposite side of the movement direction or the movement The data corresponding to the direction area is sequentially initialized.

Thus, if the position of an arbitrary ground coordinate is designated in the vicinity of the autonomous vehicle C on the base map, the sensor coordinate system external data held at that position in the base map can be accessed.
Furthermore, in this embodiment, the map creation module 40A of the map creation unit 40 is necessary to determine the travel route R of the autonomous vehicle C from the travel route determination module 40B toward the travelable area, as shown in FIG. The position at which the autonomous vehicle C arrives during this route determination processing time in consideration of the length of the route determination processing time by the travel route determination module 40B when a request for a local map is issued at the position T2. A local map Zp facing the necessary direction starting from T3 is cut out from the base map Zb and sent to the travel route determination module 40B.

  That is, when the position of the autonomous vehicle C and the direction of travel are changed during the route determination process by the travel route determination module 40B, or when there is a delay between the route determination and the actual operation of the vehicle body drive unit 50. Even if there is, in other words, even if there is a change in the position of the autonomous traveling vehicle C and the heading direction within the route determination control cycle, the autonomous traveling vehicle C arrives when the control is actually started. Since the local map Zp that faces the necessary direction starting from the arrival position T3 is cut from the base map Zb and sent to the travel route determination module 40B, the position T3 to be traveled from the autonomous traveling vehicle C is estimated. It is possible to determine and control the travel route R using an accurate relative map.

Next, a procedure for creating the travel route determination map of the autonomous vehicle C described above will be described.
First, the data analysis unit 30 processes the sensor device into sensor coordinate system external data such as distance data obtained from the external measurement unit 10 and ground coordinate system self-position data obtained from the self-position measurement unit 20 such as vehicle speed and yaw rate. And attach the correct time stamp considering the communication delay.

Subsequently, based on the sensor coordinate system external world data to which the time stamp is attached, the obstacle detection module 30A of the data analysis unit 30 performs the determination process of the travelable area and the travel impossible area due to the obstacle. Specifically, based on the sensor coordinate system distance data obtained by the laser range finder 11, an area having a height with respect to the road surface is determined as an obstacle.
On the other hand, the self-position information generation module 30B that receives the ground coordinate system self-position data based on the vehicle speed, the yaw rate, etc. obtained by the self-position measuring unit 20 for self-position estimation receives the above-mentioned ground coordinate system self-position data. Similarly, a correct time stamp considering the processing of the sensor device and the communication delay is attached, and a self-position estimation result is generated. Specifically, dead record information is generated by integrating the vehicle speed and the yaw rate.

  Next, in the map creation module 40A of the map creation unit 40, time-stamped sensor coordinate system external data (laser range finder data 11a, image processing data 12a, other sensor data 13a) and ground coordinate system self-position data 21a are used as data. The data is received from the analysis unit 30 and stored in the ring buffers 31 to 34, respectively. At this time, any stored data can be accessed using the time stamp as an index.

Then, each time the latest sensor coordinate system outside world data is measured, the map creation module 40A of the map creation unit 40 correctly recognizes the position of the autonomous vehicle C at that time based on the time stamp and returns to the ground coordinate system. And consistent base maps that successively reflect the latest sensor coordinate system external world data are continuously created.
Next, the map generation module 40A performs this travel at a stage where a request for a local map necessary for determining the travel route R of the autonomous vehicle C toward the travelable region from the travel route determination module 40B is issued at the position T2. Considering the length of the route determination processing time by the route determination module 40B, a local map Zp facing the necessary direction starting from the position T3 where the autonomous vehicle C arrives during the route determination processing time is represented as the base map Zb. And is sent to the travel route determination module 40B.

The travel route determination module 40B determines the travel route R based on the local map Zp and outputs a command signal to the vehicle body control unit 60. The vehicle body control unit 60 determines the steering angle and speed, and the vehicle body drive unit 50. When the control signal is output to the steering means 51 and the vehicle speed control means 53, the autonomous traveling along the traveling route R of the autonomous traveling vehicle C is performed.
In the above-described embodiment, the case where the autonomous mobile body is an autonomous vehicle is shown, but the present invention is not limited to this.

It is a block diagram which shows one Embodiment of the map preparation apparatus for the travel route determination of the autonomous mobile body which concerns on this invention. It is side surface explanatory drawing of the autonomous vehicle which mounts the map preparation apparatus for travel route determination in FIG. It is a block diagram which shows the map creation flow of the map preparation apparatus for travel route determination in FIG. It is explanatory drawing which shows roughly the map preparation point of the map preparation module of the map preparation apparatus for travel route determination in FIG. It is a perspective explanatory view showing a ring buffer of a map creation module of the map creation device for travel route determination in FIG. It is a conceptual diagram explaining the two-dimensional periodic boundary condition of the map creation module of the map creation device for travel route determination in FIG. It is explanatory drawing which shows roughly the condition which cuts out the local map of the map creation module of the map creation apparatus for travel route determination in FIG. 1 from a base map.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Map generation apparatus 10 for determination of travel route of autonomous mobile body External measurement unit 11 Laser range finder 20 Self-position measurement unit 30 Data analysis units 31 to 34 Ring buffer 40 Map creation unit 40A Map creation module 40B Travel route determination module C Autonomous Traveling vehicle (autonomous vehicle)
R Travel route T3 Position where autonomous vehicle reaches Zb Base map Zp Local map

Claims (2)

A map creation device used to determine the travel route of a mobile object that travels autonomously,
An external measurement unit that includes a sensor such as a laser range finder, and measures the presence or absence of obstacles from the vicinity of the moving body to a distance,
A self-position measuring unit for obtaining the self-position of the moving body by means such as dead reckoning;
A time stamp is attached to the sensor coordinate system external data obtained by the external measurement unit to perform a determination process of a travelable region and a travel impossible region due to a fault, and the ground coordinate system self-position data obtained by the self-position measurement unit A data analysis unit for generating a self-position estimation result with a time stamp,
A time-stamped sensor coordinate system outside world data and ground coordinate system self-position data obtained from the data analysis unit are provided in a time series, and each time the latest sensor coordinate system outside world data is measured. To retrieve the latest data from the ring buffer at or near the arbitrary time , recognize the position of the moving object at that time, perform coordinate conversion to the ground coordinate system, and obtain the latest sensor coordinate system external data. The mobile body has a map creation module for creating a ring buffer-like base map having spatially reflected spatial two-dimensional periodic boundary conditions, and based on the base map created by the map creation module, A map creation unit equipped with a travel route determination module that determines the travel route of
The map creation module of the map creation unit is configured so that, when a request for a local map necessary for determining a travel route of a moving body toward the travelable area is issued from the travel route determination module, the travel route determination module In consideration of the length of the route determination processing time, a local map facing the necessary direction starting from the position where the mobile body arrives during the route determination processing time is cut out from the base map and the travel route determination module A map creation device for determining a traveling route of an autonomous traveling moving body. A method of creating a map used to determine the travel route of a mobile object that travels autonomously,
With a sensor such as a laser range finder, the presence or absence of the obstacle from the vicinity of the moving body to the distance is measured, and the self-position of the moving body is determined by means such as dead reckoning,
The sensor coordinate system external world data obtained by the sensor is attached with a time stamp to determine the runnable area and the non-runnable area due to obstacles, and time is taken to the ground coordinate system self-position data obtained by means such as dead reckoning. Generate a self-position estimation result with a stamp,
Following this, the sensor coordinate system outside world data with time stamp and the ground coordinate system self-position data are accumulated in the ring buffer in time series, and from the ring buffer every time the latest sensor coordinate system outside world data is measured. A space in which the latest sensor coordinate system external data is sequentially reflected by extracting various data at the latest time or in the vicinity thereof, recognizing the position of the moving object at that time, performing coordinate conversion to the ground coordinate system A ring buffer-like base map with a typical two-dimensional periodic boundary condition ,
Considering the length of time required to determine the travel route in the step of obtaining a local map necessary for determining the travel route of the mobile body toward the travelable region based on the ring buffer-shaped base map In this travel route determination processing time, a portion facing the necessary direction starting from the position where the mobile body arrives is cut out from the base map to be a local map necessary for determining the travel route. A map creation method for determining a travel route of a featured autonomous mobile vehicle.

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