JP2007334435A - Autonomous traveling vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely avoid a collision without abruptly decelerating and stopping and also smoothly performing autonomous travelling in an autonomous travelling vehicle capable of travelling in all directions. <P>SOLUTION: An autonomous travelling vehicle autonomously travelling on the basis of stored map information comprises a travelling means 2 for travelling and moving in almost all directions; an obstacle detection sensor 3 detecting an obstacle to be an obstacle in moving; and a travelling control means 4 storing map information and controlling the travelling means 2 while avoiding a collision with the obstacle detected by the sensor 3 on the basis of the map information. The control means 4 limits the movement of the vehicle in a lateral direction to almost zero and controls the travelling means 2 around a turning movement center as a control center so as to perform movement of two degree of freedom in an anteroposterior direction and turning, and sets the control center at an obstacle position with high possibility of collision or around the vehicles including the vehicle close to the obstacle position in changing the moving direction in order to avoid the obstacle. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an autonomous mobile vehicle that can move in all directions.

2. Description of the Related Art Conventionally, there is known a movable vehicle that includes an obstacle detection sensor and moves in all directions while avoiding a collision with an obstacle based on the output of the sensor. Such a vehicle uses a characteristic that can move in all directions to make collision avoidance more reliable without sudden deceleration stop and to achieve smoother movement (for example, Patent Document 1).
JP 2002-225741 A

  However, the movable vehicle that can move in all directions as shown in Patent Document 1 described above is a power vehicle that has power for movement, and is a so-called power assist operation that moves according to an operation that the operator pushes or pulls. This is a powered vehicle, not an autonomous mobile vehicle. In recent years, autonomous mobile vehicles that have a transport function and a service function and can move more smoothly, such as various work robots and guide robots, have been demanded from the viewpoint of labor saving, human power substitution, service improvement, and the like.

  An object of the present invention is to solve the above-described problems, and to provide an autonomous mobile vehicle capable of omnidirectional movement that can more reliably avoid collisions without sudden deceleration and stop and can realize smoother autonomous movement. The purpose is to provide.

  In order to achieve the above object, an invention according to claim 1 is an autonomous mobile vehicle that autonomously moves based on stored map information, and travel means that can travel in almost all directions, and obstacles in traveling. An obstacle detection sensor for detecting an obstacle to be used, and travel control for storing the map information and controlling the travel means while avoiding a collision with the obstacle detected by the sensor based on the map information And the travel control means uses the center of the rotational motion as a control center so as to perform the motion in the front-rear direction and the two degrees of freedom of rotation while limiting the lateral movement of the vehicle to substantially zero. The control center is set around the vehicle including the obstacle position having a high possibility of collision or the vehicle close to the obstacle position when the moving direction is changed to control the traveling means and avoid the obstacle. Is shall.

  According to a second aspect of the present invention, in the autonomous mobile vehicle according to the first aspect, the traveling control means sets the control center at the front center of the vehicle when there is no obstacle that needs to be avoided. .

  According to a third aspect of the present invention, in the autonomous mobile vehicle according to the first aspect, the travel control means sets the control center at the front and rear of the vehicle when there is an obstacle that needs to be avoided while the vehicle is turning. It is set on the center line of the direction and at a position closest to the obstacle.

  According to a fourth aspect of the present invention, in the autonomous mobile vehicle according to the first aspect, the travel control means is configured such that when the vehicle turns around a corner portion of the movement route imitating an obstacle for changing the movement direction, The control center is set at the end of the corner portion, and the traveling means is controlled so as to perform a rotational motion around the control center while the vehicle is turning the corner portion.

  According to a fifth aspect of the present invention, in the autonomous mobile vehicle according to the fourth aspect, the traveling control means controls the control when the vehicle turns a corner portion to change the moving direction from a wide moving route to a narrow moving route. The rotary motion starts at a position where the vertical leg that is lowered from the center to the center line in the front-rear direction of the vehicle is closer to the front of the vehicle, and the vehicle turns around the corner and moves from a narrow movement route to a wide movement route. When the direction is changed, the rotational motion is started at a position where the leg of the perpendicular line is located behind the vehicle.

  According to the first aspect of the invention, since the degree of freedom of movement is two degrees of freedom in the front-rear direction and the rotational direction while being movable in almost all directions, It can be easily applied to autonomous movement control, and collision avoidance can be ensured without sudden deceleration and stop, and smoother autonomous movement can be realized. In addition, when changing the direction of movement to avoid obstacles, the center of rotational movement of the vehicle can be set to an arbitrary position due to the possibility of movement in almost all directions, and the control center that is the center of rotational movement is set as the obstacle. Near the vehicle, i.e., the position of an obstacle with a high possibility of a collision or the vicinity of a vehicle including a vehicle close to the obstacle position, the approach between the obstacle and the vehicle can be restricted. Collisions can be avoided.

  According to the invention of claim 2, since the control center is set at the center of the front part of the vehicle, which is the front part of the moving direction of the vehicle, the movement trajectory of the front part of the vehicle can be made to substantially coincide with the planned movement path, Efficient movement is possible.

  According to the invention of claim 3, the vehicle is suddenly decelerated and stopped by the movement of the control center for the collision with the inner obstacle due to the inner wheel difference when turning the vehicle or the collision with the outer obstacle due to the outer wheel difference. Can be avoided smoothly. That is, when there is an obstacle inside the turn at the start of turning, the point on the center line of the vehicle closest to the obstacle exists near the front of the vehicle. By using this point as the control center, the obstacle and the vehicle You can avoid the collision by preventing the approach. In addition, when there is an obstacle outside the turn at the start of turning, the point on the center line of the vehicle closest to the obstacle exists on the rear side of the vehicle. By using this point as the control center, the obstacle and the vehicle You can avoid the collision by preventing the approach.

  According to the invention of claim 4, when an obstacle such as a corner is turned around, the control center of the vehicle is set on the obstacle side, thereby maintaining a constant distance between the obstacle and the vehicle while avoiding a collision. It can wrap around smoothly.

  According to the fifth aspect of the invention, the difference between the inner wheel and the outer wheel that occurs when the vehicle turns can be generated according to the width of the moving path, so that the vehicle avoids a collision with the side wall of the moving path. The corner can be bent smoothly.

  Hereinafter, an autonomous mobile vehicle according to an embodiment of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 shows a block configuration of an autonomous mobile vehicle 1 according to the first embodiment of the present invention, FIGS. 2 (a) and 2 (b) show a wheel assembly 20 used in the autonomous mobile vehicle 1, and FIG. The outline of the vehicle outer shell 10 of the moving vehicle 1 and the arrangement of the wheel assembly 20 are shown, and FIGS. 4A and 4B show the concept of translational motion and rotational motion of the autonomous mobile vehicle 1.

  As shown in FIG. 1, the autonomous mobile vehicle 1 is a vehicle that moves autonomously based on stored map information, and travel means 2 that can travel in almost all directions, and obstacles that hinder travel. Obstacle detection sensor 3 for detecting an object and travel control means for storing the map information and controlling the travel means 2 while avoiding a collision with the obstacle detected by the sensor based on the map information. 4 is provided.

  The traveling means 2 includes a wheel assembly 20 that is a universal wheel type omnidirectional driving wheel, a motor 21 that drives the wheel assembly 20, a motor driver 22 that supplies electric power to the motor 21, and the rotational speed of the motor 21. Four sets of drive devices, each of which includes an encoder 23 to be monitored, are configured.

  As shown in FIGS. 2 (a) and 2 (b), the wheel assembly 20 has two wheels arranged in parallel with four barrels 24 arranged on the outer periphery of a frame 26 coupled to the central axle 25. It is configured. Each barrel 24 is rotatable about a support shaft orthogonal to the central axle 25. The outer shape of the cross section including the support shaft of each barrel 24 forms a circle centered on the central axle 25. The two wheels are shifted from each other by an angle of 45 ° around the central axle 25 to shift the pitch. As a result, one of the barrels 24 can always be grounded.

  The wheel assembly 20 has each axis of each barrel 24 as a rotation axis for active rotation around a central axle 25 driven by a motor 21 and for movement along the longitudinal direction of the center axle 25. Passive rotation allows omnidirectional movement. The arrow DR indicates the driving rotation direction of each central axle 25, and the arrow FR indicates the free rotation direction of each barrel 24. The arrangement of the wheel assemblies 20 of the four drive units in the autonomous mobile vehicle 1 will be described later (FIG. 3).

  The obstacle detection sensor 3 includes a front sensor 31, a rear sensor 32, a right side sensor 33, and a left side sensor 34. The obstacle detection sensor 3 detects an obstacle around the entire periphery of the autonomous mobile vehicle 1 and measures the distance. These sensors can be constituted by a laser radar, an ultrasonic array sensor capable of acquiring a distance image, or the like.

  The traveling control means 4 processes the input signals from the outside such as the obstacle detection sensor 3 and the encoders 23 of the traveling means 2 and the input signals from the storage section etc. A central control unit 40 for controlling, a map information storage unit 41 for storing map information of a traveling and moving area, a route information storage unit 42 for storing information on a moving route such as a destination and a relay point of the moving route, and a fault A self-position determining unit 43 that determines the self-position based on outputs of the object detection sensor 3 and the encoder 23 and map information stored in the map information storage unit 41 is provided.

  Further, the traveling control means 4 includes a control center determining unit 5, a moving speed determining unit 6, and a motor speed determining unit 7. These perform processing characteristic of the omnidirectional movement for controlling the traveling means 2 so that the traveling means 2 can travel in almost all directions.

  Next, the operation of each of the determining units 5, 6, 7 and the autonomous mobile vehicle 1 will be described. As shown in FIG. 3, the autonomous mobile vehicle 1 has a substantially rectangular outer shell 10. The autonomous mobile vehicle 1 can move in almost all directions, and the longitudinal direction is assumed to be the front-rear direction. Here, a coordinate system (Xg, Yg) fixed to the autonomous mobile vehicle 1 is determined. In this coordinate system, the vehicle center point G, which is the intersection of the center line 11 in the front-rear direction and the center line 12 in the left-right direction, is used as the coordinate origin, the forward direction is the positive direction of Xg, and the forward direction is the positive direction of Yg. is there.

  The wheel assemblies 20 of the four drive units are symmetrically arranged on the front and rear left and right. The wheel assemblies 20 are arranged on the left and right sides of the front and rear sides of the central axle 25 so that the axial extension lines of the central axles 25 intersect at an angle 2θ at a position closer to the center of the autonomous mobile vehicle 1. Are tilted from both the Xg axis and the Yg axis. The distance between the grounding points of each wheel assembly 20 is (a + b) in the front-rear direction and (c + d) in the left-right direction.

  The positive direction of the speeds V1, V2, V3, V4 is determined so that the counterclockwise direction around the vehicle center point G of the autonomous mobile vehicle 1 is positive. The directions of these speeds V <b> 1 to V <b> 4 are directions orthogonal to the respective central axles 25.

  Here, the translational motion and the rotational motion of the autonomous mobile vehicle 1 will be described. In general, the planar motion of a rigid body can be divided into a translational motion as shown in FIG. 4A and a rotational motion as shown in FIG. 4B, and is described by these two motions. The translational motion of the autonomous mobile vehicle 1 is a motion in which the constituent parts of the autonomous mobile vehicle 1 move in parallel with each other. The rotational motion of the autonomous mobile vehicle 1 It is a movement that moves while keeping the distance of.

  Therefore, as shown in FIG. 3, the movement of the autonomously moving vehicle 1 is a coordinated motion having an angular velocity ω around the control center A, an origin at the control center A, and parallel to the coordinate system (Xg, Yg). This is described by the translational motion of the velocities Vx and Vy in the coordinate axis direction of the coordinate system (X, Y). The speed Vx is the speed in the front-rear direction of the autonomous mobile vehicle 1, and the speed Vy is the speed in the left-right direction of the autonomous mobile vehicle 1.

  The control center determination unit 5 determines the position of the control center A so that the autonomous mobile vehicle 1 can move safely and efficiently based on the state of the moving route, that is, the presence or absence of an obstacle that needs to be avoided. To do. That is, the control center determination unit 5 sets the center of the rotational motion (control center A) at a position close to the obstacle when changing the moving direction in order to avoid the obstacle. Thus, by setting the control center A at a position close to the obstacle, the approach between the obstacle and the vehicle can be restricted, and as a result, a collision with the obstacle can be avoided.

  The self-position determining unit 43 integrates the motor speed information (a minute change in the encoder) output from the encoder 23, obtains the moving distance and the rotation angle (direction) of the autonomously moving vehicle 1, and performs the vehicle by so-called dead reckoning. Find your self-position. In addition, the self-position determining unit 43 matches the map information stored in the map information storage unit 41 with the obstacle position information output from the front sensor 31 (for example, laser radar), and generates two pieces of drawing information (map information and map information). The self-position is obtained based on the difference between the obstacle information. The self-position determining unit 43 corrects the self-position obtained by the dead reckoning using the self-position obtained based on the map information. This self-position determination and correction are performed, for example, every control cycle of the travel control unit 4.

  The moving speed determination unit 6 calculates the translational movement speed and the rotation speed of the control center A from the self-position information obtained by the self-position determination unit 43 and the route information stored in the route information storage unit 42, that is, the movement. The speed (Vx, Vy, ω) is determined. If the central control unit 40 determines that an obstacle needs to be avoided based on the obstacle information output by the front sensor 31, the central control unit 40 changes the moving speed (Vx, Vy, ω) to check the obstacle. Avoid things.

  The motor speed determining unit 7 is a rotational speed on the ground contact surface of each wheel assembly 20 based on the moving speed (Vx, Vy, ω) obtained by the moving speed determining unit 6 and the control center A determined by the control center determining unit 5. The command values of V1, V2, V3, and V4 are obtained and determined. In addition, the autonomous mobile vehicle 1 can set the center of the rotational motion of the vehicle, that is, the control center A, at an arbitrary position when changing the moving direction in order to avoid obstacles. This is based on the possibility of movement in almost all directions realized by using the wheel assembly 20.

  An example of the calculation performed in the motor speed determination unit 7 will be described. As shown in FIG. 3, the control center A is assumed to be located at a position xa forward from the vehicle center point G and ya at the left. Further, the distance in the x direction from the control center A to the wheel installation point of the front wheel assembly 20 is a, the distance in the x direction from the control center A to the wheel installation point of the rear wheel assembly 20 is b, and the left wheel assembly 20 is. The y-direction distance to the wheel installation point is c, and the y-direction distance to the wheel installation point of the right wheel assembly 20 is d. The command values for the rotational speeds V1, V2, V3, and V4 of each wheel assembly 20 are obtained by the following equation (1) with respect to the moving speed (Vx, Vy, ω) of the control center A of the autonomous mobile vehicle 1. .

  For the desired moving speed (Vx, Vy, ω) of the autonomous mobile vehicle 1, the command values of the rotational speeds V1, V2, V3, V4 of the wheel assemblies 20 obtained using the above equation (1) are used as motor drivers. 22 and the speed control of the autonomous mobile vehicle 1 is performed.

  By the way, the autonomous mobile vehicle 1 restricts the movement of the vehicle in the left-right direction to substantially zero, that is, the traveling means 2 performs a motion of two degrees of freedom in the front-rear direction and the rotation with Vy = 0 in the equation (1). Even if this is controlled, it is possible to make a desired movement.

  According to the autonomous mobile vehicle 1 of the present embodiment, while being movable in almost all directions, the degree of freedom of movement can be set to two degrees of freedom, that is, the front-rear direction and the rotational direction. In addition, the two-degree-of-freedom autonomous movement algorithm that has been proven in the past can be easily applied to autonomous movement control, collision can be avoided more reliably without sudden deceleration stop, and smoother autonomous movement can be realized.

(Second Embodiment)
FIGS. 5A to 5D show a state in which the autonomous mobile vehicle 1 according to the second embodiment of the present invention bends the corner portion while moving the control center A, and FIGS. A mode that the autonomous mobile vehicle 1 turns around an obstacle, moving the control center A is shown.

  The configuration of the autonomous mobile vehicle 1 of the second embodiment is the same as that of the autonomous mobile vehicle 1 of the first embodiment. In this embodiment, the autonomous mobile vehicle 1 shows a state where it goes around a corner part or an obstacle. FIG. 5A shows a place where the autonomously moving vehicle 1 turns in the left turn corner portion P of the moving route while moving in the moving direction F. FIG. The control center determination unit 5 of the travel control unit 4 sets the control center A at the center of the front of the vehicle when there is no obstacle that needs to be avoided (for example, the state immediately before the state shown in FIG. 5A). Yes. In this way, by setting the control center A at the center of the front of the vehicle, which is the front part of the vehicle in the moving direction, the movement trajectory of the front of the vehicle can be made to substantially coincide with the planned movement path. Can move.

  Further, as shown in FIGS. 5A to 5D, the control center determining unit 5 of the travel control unit 4 is an obstacle (in this case, the corner part P) that needs to be avoided while the vehicle is turning. , Hereinafter referred to as an obstacle P), the control center A is set on the center line 11 in the front-rear direction of the vehicle and at a position closest to the obstacle P. The setting of the control center A is reviewed and moved to the optimum position every control cycle of the travel control means 4. That is, as shown in FIGS. 5A to 5D, the control center A is moved on the center line of the autonomous mobile vehicle 1 from the front position to the rear position depending on the degree of turning around the corner portion P. Yes.

  6 (a) to 6 (d) show that the wheelchair B is present as an obstacle in the movement path instead of the corner portion P described above, and the autonomous mobile vehicle 1 is around the tip portion P of the wheelchair B. Shows the sneaking around. As in the case of FIGS. 5A to 5D described above, the control center A is moved from the front position to the rear position on the center line of the autonomous mobile vehicle 1 depending on the degree of turning around the tip portion P. ing.

  According to the method of setting the control center A as described above, the collision with the inner obstacle due to the inner wheel difference during the turning of the vehicle and the collision with the outer obstacle due to the outer wheel difference are rapidly reduced by moving the control center. It can be avoided smoothly without stopping. That is, when there is an obstacle P inside the turn at the start of turning, the point on the center line 11 of the vehicle closest to the obstacle P exists closer to the front of the vehicle. Collision can be avoided by preventing the object P from approaching the vehicle. In addition, when there is an obstacle outside the turn at the start of turning, the point on the center line of the vehicle closest to the obstacle exists on the rear side of the vehicle. By using this point as the control center, the obstacle and the vehicle You can avoid the collision by preventing the approach.

  2. Description of the Related Art Conventionally, there is a vehicle that realizes an autonomous movement by considering an autonomously moving vehicle as an approximately circular shape, and making a movement plan that passes through a position away from an obstacle by a certain distance. The control center of a vehicle having an approximately circular outer shape is usually set at the center of the outer shape as being fixed to the vehicle. However, in a vehicle having a substantially rectangular outer shape and having a large difference between inner and outer wheels when turning, such as the autonomous mobile vehicle 1 according to the first and second embodiments of the present invention, the control center is the vehicle center. It is difficult to deal with obstacle avoidance if it remains fixed.

  In that respect, the autonomous mobile vehicle 1 according to the first and second embodiments of the present invention that uses the method of dynamically moving the control center A as described above avoids obstacles under smooth movement. It is possible. Moreover, the autonomous mobile vehicle 1 according to the first and second embodiments of the present invention can be obtained by adding the function of the control center determination unit 5 that moves and determines the control center to the same autonomous movement algorithm as before. Easy to realize.

(Third embodiment)
FIG. 7 shows the arrangement and detection area of the obstacle detection sensor 3 of the autonomous mobile vehicle 1 according to the third embodiment of the present invention, and FIGS. 8, 9, and 10 show the autonomous mobile vehicle 1 during autonomous movement. Indicates.

  The configuration of the autonomous mobile vehicle 1 of the third embodiment is the same as that of the autonomous mobile vehicle 1 of the first and second embodiments described above. In the present embodiment, the obstacle detection sensor 3 of the autonomous mobile vehicle 1 and the operation of the autonomous mobile vehicle 1 based on the obstacle detection result by the sensor 3 will be described. As shown in FIG. 7, the obstacle detection sensor 3 includes a front sensor 31, a rear sensor 32, a right side sensor 33, and a left side sensor 34 on the front, rear, left and right sides of the vehicle. The entire periphery is covered with detection areas 31a, 32a, 33a, and 34a. When each sensor is, for example, an angle scanning type laser radar, it is possible to measure the distance and the direction from the road surface to the position of a surface such as a wall or a moving obstacle in a horizontal plane at a predetermined height. The position of the detected obstacle is represented by a coordinate system (Xg, Yg) at the vehicle center point G and a coordinate system (X, Y) at the control center A.

  As shown in FIG. 8, the autonomous mobile vehicle 1 is used for obstacle avoidance determination when the autonomous mobile vehicle 1 turns in the regions provided on the left and right sides of the vehicle among the detection regions 31 a to 34 a described above. It is set as a necessary area. Each of the areas S1 to S4 means that if an obstacle exists in the area, the outer shell 10 of the vehicle facing the area may collide. A broken line 13 shown in FIG. 8 indicates a limit line for reliably avoiding the approach of the obstacle to the outer shell 10.

  The four regions S1 to S4 described above are divided forward and backward by the position of the control center A. The front left and right regions S1 and S4 have a width Ly from the outer shell 10 of the autonomous mobile vehicle 1 and a length L1 forward from the control center A, and the rear left and right regions S2 and S3 are from the outer shell 10 of the autonomous mobile vehicle 1. It has a width Ly and a length L2 behind the control center A. The regions S1 and S4 project forward from the outer shell 10 by a length δ1, and the regions S2 and S3 project backward from the vehicle outer shell 10 by a length δ2.

  The protrusions due to δ1 and δ2 described above are margin regions provided in order to avoid the possibility of collision when moving while turning. When the autonomous mobile vehicle 1 moves only in the left-right direction and the front-rear direction without turning, δ1 = δ2 = 0 may be set.

  Further, the width Ly is a distance that is determined that there is a possibility that the obstacle on the side surface collides with the autonomous mobile vehicle 1. In general, since the obstacle avoidance ability changes depending on the magnitude of the moving speed, the width Ly can be increased as the movement is faster, and the width Ly can be reduced as the movement is slower. Therefore, the width Ly may be a function of speed.

  In FIG. 8, when the autonomous mobile vehicle 1 travels as shown in the moving direction F in order to go around the corner portion P, the corner portion P may enter the region S <b> 1 due to an inner wheel difference of the vehicle. In addition, since the region S3 moves to the outer side of the turn due to the difference in the outer wheel of the vehicle, there is a possibility that the obstacle enters the region S3 if there is an obstacle on the right side behind the vehicle.

  FIG. 9 shows a state in which the corner portion P has entered the region S1, and at this time, the control center A is moving forward from the position of the original control center A0. Thus, the autonomous mobile vehicle 1 ensures the distance between the corner P and the control center by moving the position of the control center A forward with respect to the corner P representing the position of the obstacle. It is possible to avoid a collision with the corner portion P (obstacle).

  As described above, the autonomous mobile vehicle 1 including the wheel assembly 20 that can move in all directions can arbitrarily move the control center A. When the position of the control center A changes, the coordinate system (X, Y) defined for the control center A also moves. Therefore, whenever the position of the control center A is changed, the control center determination unit 5 converts the coordinate value of the obstacle detected by the sensor 3 into a new coordinate system value.

  Further, as shown in FIG. 10, when the autonomous mobile vehicle 1 tries to perform a left turn operation, a corner portion P and an obstacle that may enter the left front area S1 and the right rear area S3, respectively. When P2 exists, the control center determination unit 5 performs a calculation for moving the control center A forward in association with the corner portion P and a calculation for moving the control center A backward in association with the obstacle P2. . When the control center A moves, the areas and arrangements of the regions S1 to S4 change, so that the degree of obstacle entry into the regions S1 and S2 out of the control center position of the previous calculation and the control center position of the next calculation result One with less is required. When the degree of obstacle entry exceeds the predetermined allowable range, the central control unit 40 stops the turning operation, performs the forward operation according to the preset allowable range, and then tries the turning operation. Further, when the advance distance exceeds the allowable range, the traveling movement is stopped.

(Fourth embodiment)
FIG. 11 shows an example in which the control center is set in the corner portion in the autonomous mobile vehicle 1 according to the fourth embodiment of the present invention, and FIGS. 12, 13, and 14 show how the autonomous mobile vehicle 1 bends in the corner portion. Shown continuously overlaid.

  The configuration of the autonomous mobile vehicle 1 in this embodiment is the same as that of the autonomous mobile vehicle 1 of the first embodiment. As shown in FIGS. 11 and 12, the autonomous mobile vehicle 1 according to the present embodiment travels around the corner portion P of the travel route that looks like an obstacle for changing the travel direction F of the vehicle. The control center determining unit 5 sets the control center A at the tip of the corner portion P, and the row control unit 4 controls the traveling unit 2 so as to perform a rotational motion around the control center A. Such rotational movement around the control center A is performed while the autonomous mobile vehicle 1 bends the corner portion P.

  When the autonomous mobile vehicle 1 performs only the rotational motion around the control center A, the command values of the rotational speeds V1, V2, V3, and V4 of the wheel assemblies 20 are Vx = Vy in the above equation (1). = 0 and only the angular velocity ω needs to be given, and is obtained as in the following equation (3).

  The turning movement speed Vr of the autonomous mobile vehicle 1 is obtained as Vr = r · ω by the relational expression between the rotation radius r and the angular speed ω in the rotary motion. Therefore, the magnitude of the angular velocity ω may be determined so that Vr ≦ Vx with respect to the normal forward speed Vx of the autonomous mobile vehicle 1.

  Thus, according to the present embodiment in which the control center of the vehicle is set on the obstacle side when the obstacle such as the corner portion P goes around, the distance d between the obstacle and the vehicle is kept constant, It is possible to smoothly go around while avoiding the collision.

  Further, as shown in FIG. 13, the position at which the above-described rotational motion is started is determined by the boundary between the autonomous moving vehicle 1 turning around the corner portion P and from the narrow moving path surrounded by the boundaries W1 and W3 of the traveling path. , W4, when the moving direction F is changed to a wide moving path, the position where the perpendicular foot drawn from the control center A to the center line in the front-rear direction of the vehicle 1 is closer to the rear of the vehicle, that is, in the figure For the dimensions d1 and d2 shown in FIG.

  Similarly, as shown in FIG. 14, when the vehicle 1 bends a corner portion P to change the moving direction from a wide moving path to a narrow moving path, the position where the perpendicular foot is behind the vehicle, that is, For the dimensions d1 and d2 shown in the figure, the rotational motion may be started at a position where d1 <d2.

  By starting the rotational movement as described above, the inner wheel difference and the outer wheel difference generated when the autonomous mobile vehicle 1 turns can be generated according to the width of the travel route. The corner portion can be smoothly bent while avoiding a collision with a side wall or the like.

(Fifth embodiment)
FIG. 15 shows an example in which the control center is set at the corner of the vehicle in the autonomous mobile vehicle 1 according to the fifth embodiment of the present invention, and FIG. 16 (a) shows how the autonomous mobile vehicle 1 leaves the wall. FIG. 16 (b) shows a collision example of a general vehicle leaving the wall. The configuration of the autonomous mobile vehicle 1 is the same as that of the autonomous mobile vehicle 1 of the first embodiment. In this embodiment, as shown in FIG. 15, the autonomously moving vehicle 1 leaves in the direction of the moving direction F as shown in FIG. In this case, an example in which the control center A is set behind the wall W is shown. Since the autonomous mobile vehicle 1 recognizes its own position and also recognizes the obstacle situation around itself, such movement and setting of the control center A can be performed when leaving the wall W. it can. Then, by setting the control center A as described above, it is possible to avoid a collision with the wall W of the vehicle rear portion Q as shown in FIG.

(Sixth embodiment)
FIG. 17 shows the arrangement of vehicle outlines and drive wheels of an autonomous mobile vehicle according to the sixth embodiment of the present invention. The autonomous mobile vehicle 1 of the present embodiment is different from the autonomous mobile vehicle 1 of the first to fifth embodiments described above in the arrangement of the four wheel assemblies 20, and the other configurations are the same as those described above. It is the same.

  The wheel assembly 20 that can travel and move in all directions of the autonomously moving vehicle 1 has a central axle direction parallel to each side of the substantially rectangular vehicle outer shell 10. That is, the speeds V2 and V4 on the ground contact surfaces of the wheels of the left and right wheel assemblies 20 are the front and rear directions, and the speeds V1 and V3 on the ground contact surfaces of the front and rear wheel assemblies 20 are the left and right directions. In such an autonomous mobile vehicle 1, the command values of the rotational speeds V1, V2, V3, and V4 of the wheel assemblies 20 with respect to the moving speed (Vx, Vy, ω) of the control center A are obtained by the following equation (4). It is done.

(Seventh embodiment)
FIG. 18 shows an arrangement of vehicle outlines and drive wheels of an autonomous mobile vehicle according to the seventh embodiment of the present invention. The autonomous mobile vehicle 1 is configured by arranging three wheel assemblies 20 that can travel and move in all directions in a triangular shape. The rotational speeds V1, V2, and V3 of the wheel assemblies 20 with respect to the movement speed (Vx, Vy, ω) of the control center A are obtained in the same manner as the autonomous mobile vehicle 1 of the first embodiment.

  The present invention is not limited to the above-described configuration, and various modifications can be made. For example, a configuration in which five or more wheel assemblies 20 are provided may be employed.

The block block diagram of the autonomous mobile vehicle which concerns on the 1st Embodiment of this invention. (A) is a side view of the drive wheel used for an autonomous mobile vehicle same as the above, (b) is a front view of the wheel. The top view which shows the arrangement | positioning which looked at the vehicle outline of the autonomous mobile vehicle same as the above, and the wheel assembly for a drive from the upper direction. (A) is a top view explaining the concept of the translation movement of an autonomous mobile vehicle same as the above, (b) is a top view explaining the concept of the rotation movement. (A)-(d) is a top view which shows a mode that the autonomous mobile vehicle which concerns on the 2nd Embodiment of this invention bends a corner part, moving a control center in time series. (A)-(d) is a top view which shows a mode that an autonomous mobile vehicle same as the above turns around an obstacle, moving a control center. The top view which shows arrangement | positioning and the detection area | region of the obstacle detection sensor of the autonomous mobile vehicle which concerns on the 3rd Embodiment of this invention. The top view which shows a mode that an autonomous mobile vehicle same as the above moves autonomously, detecting an obstruction. The top view which shows a mode that an autonomous mobile vehicle same as the above bends a corner part. The top view which shows the other example of a mode that an autonomous mobile vehicle same as the above bends a corner part. The top view which shows the example which sets a control center to a corner part in the autonomous mobile vehicle which concerns on the 4th Embodiment of this invention. The top view which shows a mode that an autonomous mobile vehicle same as the above bends a corner part continuously. The top view which shows the other example of a mode that an autonomous mobile vehicle same as the above bends a corner part continuously. The top view which shows further another example of a mode that an autonomous mobile vehicle same as the above bends a corner part continuously. The top view which shows the example which sets the control center to the corner part of a vehicle in the autonomous mobile vehicle which concerns on the 5th Embodiment of this invention. (A) is a top view which shows a mode that an autonomous mobile vehicle same as the above leaves | separates from a wall, (b) is a top view which shows the collision example of the general vehicle which leaves | separates from a wall. The top view which looked at arrangement | positioning of the vehicle outline and drive wheel of the autonomous mobile vehicle which concerns on the 6th Embodiment of this invention from upper direction. The top view which looked at arrangement | positioning of the vehicle outline and drive wheel of the autonomous mobile vehicle which concerns on the 7th Embodiment of this invention from upper direction.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Autonomous mobile vehicle 2 Traveling means 3,31-34 Obstacle detection sensor 4 Traveling control means A, A0, A1 Control center P, P2 Obstacle

Claims (5)

An autonomous mobile vehicle that moves autonomously based on stored map information,
Traveling means that allows traveling in substantially all directions;
An obstacle detection sensor for detecting obstacles that become obstacles during movement;
Travel control means for controlling the travel means while storing map information and avoiding a collision with an obstacle detected by the sensor based on the map information;
The travel control means controls the travel means with the center of the rotational motion as a control center so as to perform the motion of two degrees of freedom in the front-rear direction and the rotation after limiting the movement of the vehicle in the left-right direction to substantially zero. When changing the moving direction to avoid an obstacle, the control center is set around the vehicle including an obstacle position having a high possibility of collision or the vehicle close to the obstacle position. Autonomous mobile vehicle.   2. The autonomous mobile vehicle according to claim 1, wherein the travel control unit sets the control center at the front center of the vehicle when there is no obstacle that needs to be avoided.   The travel control means sets the control center on the center line in the front-rear direction of the vehicle and a position closest to the obstacle when there is an obstacle that needs to be avoided while the vehicle is turning. The autonomous mobile vehicle according to claim 1.   The travel control means sets the control center at the tip of the corner portion when the vehicle turns around the corner portion of the movement route that imitates the obstacle because the vehicle direction is changed, and the vehicle 2. The autonomous mobile vehicle according to claim 1, wherein the traveling means is controlled so as to perform a rotational motion around the control center while turning.   When the vehicle turns around the corner and changes the direction of travel from a wide travel route to a narrow travel route, the travel control means is configured such that a vertical leg that is lowered from the control center to the center line in the front-rear direction of the vehicle The rotational motion is started at a position that is closer to the front of the vehicle, and when the vehicle turns a corner and changes the direction of travel from a narrow travel path to a wide travel path, the perpendicular foot 5. The autonomous mobile vehicle according to claim 4, wherein the rotational motion is started at a position.

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