Patent Publication Number: US-9884645-B2

Title: Lane change control system

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     The present application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. 2015-234439, filed Dec. 1, 2015, entitled “Lane Change Control System.” The contents of this application are incorporated herein by reference in their entirety. 
     BACKGROUND 
     1. Field 
     The present disclosure relates to a lane change control system that controls vehicle lane changing. 
     2. Description of the Related Art 
     Japanese Unexamined Patent Application Publication No. 2008-12989 describes a lane change assist system that assists lane change of a vehicle. The lane change assist system uses a camera to capture an image of the road ahead of the vehicle in a direction of progress and identify white lines on both left and right sides, acquires a lane width from the white lines, computes a curve radius and the like, and calculates a target yaw rate (see [0023], [0024], [0025], Equation 2, [0053], and [0054] in Japanese Unexamined Patent Application Publication No. 2008-12989). 
     Paragraph [0016] in Japanese Unexamined Patent Application Publication No. 2008-12989 describes that the vehicle can be guided from a current driving lane to a lane change target lane by performing steering control that takes the lane width into account, thereby enabling lane change to be assisted. 
     However, Japanese Unexamined Patent Application Publication No. 2008-12989 does not consider cases in which objects are present either in the lane change target lane or in the vicinity of the lane change target lane. There is accordingly room for improvement since it may not be possible to perform lane changing appropriately, which could, for example, alarm an occupant of the vehicle that is attempting to change lanes (that is in the process of changing lanes). 
     SUMMARY 
     The present disclosure provides a lane change control system capable of performing lane change control appropriately in cases in which an object is present in a lane change target lane or in the vicinity thereof. 
     The present disclosure describes a lane change control system including: a surrounding environment acquisition section that acquires information of a surrounding environment such as, typically, a captured image data of a surrounding environment at least in front of a vehicle; a lane marking/object detection section that detects a lane marking and an object in the acquired surrounding environment; a lane change controller that controls lane changing of the vehicle according to the lane marking and object detected; and an object determination section that determines whether or not the object detected in the surrounding environment is present in a lane change target lane or in the vicinity of the lane change target lane. The lane change controller reduces a predetermined lateral acceleration or lateral velocity in cases in which the detected object has been determined to be an object present in the lane change target lane or in the vicinity of the lane change target lane, and performs lane change control. 
     In the present disclosure, the predetermined lateral acceleration or lateral velocity is reduced during lane change control in cases in which the object detected by the lane marking/object detection section is determined to be an object present in the lane change target lane or in the vicinity of the lane change target lane. Accordingly, it is possible to avoid alarming an occupant of the vehicle that is attempting to change lanes, and lane change control can be performed appropriately. 
     In such cases, configuration may be made in which the object determination section further includes functionality to classify the detected object by type; and the lane change controller changes a reduction ratio of the lateral acceleration or the lateral velocity according to the type of the object classified by the object determination section. This thereby enables an appropriate reduction ratio to be set for the lateral acceleration or the lateral velocity according to the type of the classified object. 
     Moreover, configuration may be made in which the lane change controller changes the reduction ratio such that the lateral acceleration or the lateral velocity is smaller in cases in which the detected object is classified as a person than as an object other than a person. This thereby avoids alarming the person present in or in the vicinity of the lane into which the vehicle is attempting to change, and at the same time, avoids alarming occupants of the vehicle that is attempting to change lanes. 
     In particular, configuration may be made in which the reduction ratio is changed such that the lateral acceleration or the lateral velocity is smaller in cases in which the person detected and classified has been classified as a person riding a bicycle than as a pedestrian. This thereby avoids alarming the person riding a bicycle in, or in the vicinity of, the lane into which the vehicle is attempting to change, and at the same time, avoids alarming occupants of the vehicle that is attempting to change lanes. 
     Note that configuration may be made in which the predetermined lateral acceleration or lateral velocity is set to a lateral acceleration or lateral velocity that becomes smaller in value the narrower a lane change target lane width. This thereby enables lane change to be controlled at an appropriate speed that neither alarms the occupant, nor feels slow to the occupant. 
     Moreover, configuration may be made in which the reduction ratio is changed such that the lateral acceleration or the lateral velocity is smaller in cases in which the detected object has been determined to be an object present in the lane change target lane or in the vicinity of the lane change target lane and the object has been determined to be a stationary vehicle from which there is a possibility of an occupant exiting, than when the object has been determined to be a stationary vehicle from which there is no possibility of the occupant exiting. This thereby enables an appropriate lateral acceleration or lateral velocity to be set even when there is a possibility that the door of a stationary vehicle may open. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram illustrating configuration of a vehicle installed with a lane change control system according to an embodiment. 
         FIG. 2A  is a graph illustrating characteristics of a maximum lateral acceleration of a vehicle in a lane width direction with respect to an adjacent lane width. 
         FIG. 2B  is a graph illustrating characteristics of a maximum lateral velocity of a vehicle in a lane width direction with respect to an adjacent lane width. 
         FIG. 3  is a flowchart to assist explanation of operation of a lane change control system according to an embodiment. 
         FIG. 4A  is an explanatory diagram illustrating a state in which there is no object present in a lane change target lane, and a vehicle is traveling in a direction X along a lane near a median strip. 
         FIG. 4B  is an explanatory diagram illustrating a state in which an object is present in a lane change target lane, and a vehicle is traveling in a direction X along a lane near a median strip. 
         FIG. 5A  is graph to explain calculation of a maximum lateral acceleration for a specific adjacent lane width. 
         FIG. 5B  is a graph to explain calculation of a maximum lateral velocity for a specific adjacent lane width. 
         FIG. 6  is a diagram illustrating reduction ratios for maximum lateral acceleration or maximum lateral velocity according to object types. 
         FIG. 7  is a schematic plan view illustrating examples of lane change paths generated according to object types. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Detailed explanation follows regarding a preferred exemplary embodiment of a lane change control system according to the present disclosure, with reference to the accompanying drawings. 
       FIG. 1  is a block diagram illustrating configuration of a vehicle  10  installed with a lane change control system  12  according to the present embodiment. 
     The vehicle  10  is capable of switching operation between that of an automatically driven (encompassing automatically drive-assistance) vehicle, or that of a manually driven vehicle. In the present embodiment, the vehicle  10  functions as an automatically driven (encompassing automatically drive-assistance) vehicle. 
     As illustrated in  FIG. 1 , the lane change control system  12  fundamentally includes vehicle state sensors  20 , surrounding environment sensors  30 , a navigation device (NAVI)  36 , a communication device  37 , an electronic control unit  40  (referred to below as the ECU  40 ), a steering device  62 , a drive device  64 , a braking device  66 , a display device  70 , and a speaker  72 . 
     The ECU  40  is a computer including a microcomputer, and includes a Central Processing Unit (CPU), ROM (encompassing EEPROM) as memory, and Random Access Memory (RAM), as well as input/output devices such as an A/D converter and a D/A converter, a timer serving as a clock, and the like. The ECU  40  functions as various functional execution sections (functional execution units) by reading and executing programs stored in the ROM with the CPU. 
     More specifically, in the lane change control system  12 , the ECU  40  functions as a computation section  50  including a lane marking/object detection section  42 , an object determination section  44 , and a lane change controller  46 . The ECU  40  also functions as a storage section  52 , an input/output section  54 , and the like. 
     The vehicle state sensors  20  include, for example, a vehicle velocity sensor  22 , a steering angle sensor  24 , a lateral acceleration sensor  26 , and a yaw rate sensor  28 , and detect information relating to states of the vehicle  10 . The vehicle state sensors  20  function as a vehicle state detection section. 
     The surrounding environment sensors  30  include, for example, a camera  32  and a radar  34 , and detect information relating to the surrounding environment in front of, to the sides of, and behind the vehicle  10 , for example. The surrounding environment sensors  30  function as a surrounding environment acquisition section. 
     The vehicle velocity sensor  22  detects a vehicle velocity V (m/s) of the vehicle  10  and outputs the vehicle velocity V to the ECU  40 . The steering angle sensor  24  detects a steering angle θ (rad) of the vehicle  10  and outputs the steering angle θ to the ECU  40 . 
     The lateral acceleration sensor  26  detects a lateral acceleration GI (m/s 2 ), this being acceleration arising in a lateral direction (width direction) of the vehicle  10 , and outputs the lateral acceleration GI to the ECU  40 . The lateral acceleration sensor  26  is provided substantially at the position of a center of gravity at a central section of the vehicle  10  (vehicle body). Alternatively, the lateral acceleration sensor  26  may be provided at locations supporting the respective wheels, not illustrated in the drawings. 
     The yaw rate sensor  28  detects a yaw rate Yr (rad/s), this being a rotational angular velocity about a vertical axis of the vehicle  10 , and outputs the yaw rate Yr to the ECU  40 . The yaw rate sensor  28  is provided substantially at the position of the center of gravity at the central section of the vehicle  10  (vehicle body). 
     The camera  32  (image capture unit) is, for example, a solid state camera employing a solid state image sensor such as a CCD camera or a CMOS camera (and may also be an infrared camera). The camera  32  acquires images of the surroundings (for example of objects such as other vehicles, pedestrians, or animals, as well as lane markings) around at least the front of the vehicle  10 . The camera  32  outputs signals corresponding to the images of the surroundings to the ECU  40 . 
     The radar  34  outputs transmission waves, which are electromagnetic waves (millimeter waves here), to the exterior of the vehicle  10 , including at least in front of the vehicle  10 , and receives reflected waves that are waves from out of the transmission waves that have been reflected back by detected objects (for example objects such as other vehicles and pedestrians). The radar  34  outputs signals corresponding to the reflected waves to the ECU  40 . 
     The navigation device  36  detects a current position of the vehicle  10  using a satellite system such as a Global Positioning System (GPS), and guides a user (occupant) along a route to a destination. The navigation device  36  also includes a storage device stored with road map information. The navigation device  36  detects or finds the current position of the vehicle  10  based on position information from GPS satellites and the road map information stored in the storage device. 
     From the perspective that the navigation device  36  detects the current position of the vehicle  10 , the navigation device  36  may be considered to be one of the vehicle state sensors  20 . The navigation device  36  may also be considered to be one of the surrounding environment sensors  30  that detect surrounding environment information, which is information relating to the surrounding environment around the vehicle  10 , and includes traffic rules and road restrictions around the current position of the vehicle  10 . 
     In  FIG. 1 , the navigation device  36  is envisaged as being a type that is attached to the vehicle  10 . However, there is no limitation thereto, and a portable information terminal such as a smartphone may be employed as the navigation device  36 . Moreover, the road map information may be stored in an external server (not illustrated in the drawings), and provided to the navigation device  36  as required. 
     The communication device  37  performs wireless communication with vehicles other than the vehicle  10  and with external devices such as external servers (including, for example, roadside optical beacons, and remote external terminals), either directly or via a mobile communication network such as the Internet. 
     The display device  70  performs display relating to automatic driving and the like. The display device  70  may, for example, configure part of an instrument panel meter, not illustrated in the drawings. Alternatively, the display device  70  may double as a display section of the navigation device  36 . 
     The speaker  72  outputs audio (such as audio guidance) relating to automatic driving and the like. The speaker  72  may configure part of an audio device, not illustrated in the drawings, or of the navigation device  36 . 
     The lane change controller  46  performs control that is necessary when the vehicle  10  is traveling under automatic driving. 
     More specifically, the lane change controller  46  generates a lane change path command Tcom based on vehicle state information indicating a state of the vehicle  10  detected by the vehicle state sensors  20 , or based on information obtained therefrom as well as information relating to the surrounding environment of the vehicle  10  detected by the surrounding environment sensors  30 . The lane change controller  46  then performs lane change control for the vehicle  10  by controlling the steering device  62 , the drive device  64 , and the braking device  66  based on the lane change path command Tcom. 
     Note that the vehicle state information indicating a state of the vehicle  10  detected by the vehicle state sensors  20 , or the information obtained therefrom, is, for example, a vehicle velocity Vx and acceleration Ax of the vehicle  10  in a lane direction (road length direction) X, and a vehicle velocity (also referred to as lateral velocity) Vy and acceleration (also referred to as lateral acceleration) Ay of the vehicle  10  in a direction (road width direction or lane width direction) Y that is orthogonal to the lane direction X. 
     Moreover, the surrounding environment information, which is information relating to the surrounding environment of the vehicle  10  detected by the surrounding environment sensors  30 , is, for example, information relating to a lane width of the current lane (the lane in which the vehicle  10  is traveling) as well as a lane change target lane width (also referred to as the adjacent lane width) Llane, and information relating to objects in the current lane (the lane in which the vehicle  10  is traveling) as well as objects in the lane change target lane (also referred to as the adjacent lane) and/or objects in the vicinity of the adjacent lane (also referred to as adjacent object information) Obinfo. 
     The adjacent lane width Llane and the adjacent object information Obinfo are also referred to collectively as adjacent lane information Llaneinfo. 
     The lane change controller  46  accordingly generates the lane change path command Tcom based on the adjacent lane information Llaneinfo (=adjacent lane width information Llane+adjacent object information Obinfo), and performs lane change control by controlling the steering device  62 , the drive device  64 , and the braking device  66  based on the lane change path command Tcom. 
     Note that during generation of the lane change path command Tcom, the lane change controller  46  refers to characteristics  81 , illustrated in  FIG. 2A , of a maximum lateral acceleration Aymax (m/s 2 ) of the vehicle  10  in the lane width direction Y with respect to the adjacent lane width Llane, or to characteristics  82 , illustrated in  FIG. 2B , of a maximum lateral velocity Vymax (m/s) of the vehicle  10  in the lane width direction Y with respect to the adjacent lane width Llane (m). The characteristics  81  and the characteristics  82  are stored in the storage section  52 . 
     The characteristics  81  may be stored in the storage section  52  as a function famax(Llane) of the adjacent lane width Llane as expressed in Equation 1 below, and the characteristics  82  may be stored in the storage section  52  as a function fvmax(Llane) of the adjacent lane width Llane as expressed in Equation 2 below.
 
 Ay max= fa max( L lane)  (1)
 
 Vy max= fv max( L lane)  (2)
 
     The steering device  62  includes an Electric Power Steering (EPS) system, and switches the direction of progress (steering angle θ) of the vehicle  10  based on the lane change path command Tcom from the lane change controller  46  and the like, and also applies steering power to the vehicle  10 . 
     The drive device  64  generates drive force of the vehicle  10  based on the lane change path command Tcom from the lane change controller  46  and the like. In cases in which the vehicle  10  is an engine-powered vehicle, the drive device  64  includes, for example, an engine and a transmission, not illustrated in the drawings. Alternatively, in cases in which the vehicle  10  falls under the narrow definition of a battery vehicle, the drive device  64  includes, for example, a traction motor and a transmission, not illustrated in the drawings. 
     The braking device  66  generates braking force of the vehicle  10  based on the lane change path command Tcom from the lane change controller  46  and the like. The braking device  66  includes an Anti-Lock Braking System (ABS), and also includes, for example, brake discs, brake calipers, and hydraulic mechanisms, not illustrated in the drawings. Moreover, in cases in which the vehicle  10  is an electric vehicle provided with a traction motor, not illustrated in the drawings, the braking device  66  may include part of the traction motor employed for regenerative braking. Here, “electric vehicle” is not limited to the narrow definition of battery vehicles, and encompasses hybrid vehicles, fuel cell vehicles, and the like. 
     The input/output section  54  is employed to input and output signals between the ECU  40  and the vehicle state sensors  20 , the surrounding environment sensors  30 , the navigation device  36 , the communication device  37 , the steering device  62 , the drive device  64 , the braking device  66 , the display device  70 , and the speaker  72 . 
     The computation section  50  computes based on information input from the vehicle state sensors  20 , the surrounding environment sensors  30 , and the like, and generates signals to be output to the steering device  62 , the drive device  64 , the braking device  66 , the display device  70 , and the speaker  72  based on the computation results. 
     As illustrated in  FIG. 1 , the computation section  50  includes the lane marking/object detection section  42 , the object determination section  44 , and the lane change controller  46  described above. 
     Next, explanation follows regarding fundamental operation of the lane change control system  12  of the vehicle  10  configured as described above, with reference to the flowchart of  FIG. 3 . The program illustrated in the flowchart is executed by the (CPU of) the ECU  40 . However, since the explanation would become difficult to follow if each element of the processing were to be explained in terms of being executed by the ECU  40 , this is only mentioned where necessary. The processing in the flowchart is executed at a specific cycle. 
     At step S 1 , the ECU  40  uses the vehicle state sensors  20  to acquire vehicle states such as the vehicle velocity Vs, the steering angle θ, a lateral acceleration Ayreal, and a yaw rate Yrreal. 
     At step S 2 , the ECU  40  uses the surrounding environment sensors  30  to acquire signals carrying image information of the surrounding environment captured by the camera  32 , and signals carrying object information for the surrounding environment detected by the radar  34 . 
     At step S 3 , the lane marking/object detection section  42  detects lane markings using a known method, as described later, and at step S 4 , identifies a lane. 
     The lane markings are markings indicating lane boundaries (lane partitions), and the lane markings encompass continuous lines (also referred to as lines that are continuous in effect) made up from intermittent white lines (line segments) provided at intervals, and continuous lines configured by solid white lines or the like, as well as continuous markings (these may be thought of as markings that are continuous in effect) such as Botts&#39; dots or cats&#39; eyes. 
     In such cases, at step S 3 , the lane marking/object detection section  42  acquires images of a specific luminance or greater (in which the brightness of the road surface is a specific brightness or greater) from images captured by the camera  32 . The lane marking/object detection section  42  performs differential processing while scanning an overall image (actually, portions of the image in which lane markings are present) in a horizontal direction at respective detection lines spaced a uniform distance apart from each other in a direction X (forward direction), so as to extract edges (edge images) from the overall image starting from the vehicle  10  side (base coordinate side). 
     Moreover, at step S 3  the lane marking/object detection section  42  extracts images exhibiting the characteristics of lane markings from the overall extracted images. 
     Next, at step S 4 , the lane marking/object detection section  42  identifies lanes (the current lane and the adjacent lane) made up of images exhibiting the characteristics of lane markings, in other words, made up of lines of characteristic dots that exhibit the characteristics of lane markings (when on a straight road, spacings of the lines of dots in the forward direction of the vehicle  10  correspond to uniformly distanced spacings). The lane marking/object detection section  42  also identifies lane widths of the respective lanes (lane widths of the current lane and the adjacent lane). 
     At substantially the same time as step S 4 , at step S 5 , based on signals carrying image information of the surrounding environment captured by the camera  32  and signals carrying object information of the surrounding environment detected by the radar  34  acquired through the surrounding environment sensors  30  at step S 2 , the lane marking/object detection section  42  detect objects, in this case pedestrians, moving bicycles being pedaled by cyclists, stationary vehicles, and animals, using a known method such as what is referred to as pattern matching, in which respective characteristics such as shapes are compared against characteristics such as shapes stored in advance in the storage section  52 . 
     Next, at step S 6 , the adjacent lane width Llane is detected, taking any detected objects into consideration. 
       FIG. 4A  illustrates a state in which the vehicle  10  is traveling in the direction X along a lane (also referred to as the current lane)  85  near a median strip  84 . Out of a lane (current lane, also referred to as the pre-change lane)  85  and a lane (also referred to as the adjacent lane)  87  detected or identified in a detection range  83  of the camera  32  and the radar  34 , the adjacent lane width Llane, this being the lane width of the lane change target lane (adjacent lane)  87 , is detected as L. Note that the lane  85  is formed between the median strip  84  and a lane boundary line  86 , and the adjacent lane  87  is formed between the lane boundary line  86  and a roadside (shoulder)  89  side lane boundary line  88 . In  FIG. 4A , no objects have been detected in the adjacent lane  87  within the detection range  83 . 
     As illustrated in  FIG. 4B , when an object  90  is detected in the adjacent lane  87  at step S 5 , at step S 6 , the adjacent lane width Llane is detected as Llane=Lob by adjusting for the amount that the object  90  sticks out into the side of the adjacent lane  87 . 
     Note that although not illustrated in the drawings, if, for example, a vehicle parked at the roadside  89  outside of the lane boundary line  88  of the adjacent lane  87  were to be detected or identified in the detection range  83  in  FIG. 4A  and  FIG. 4B , this vehicle would be detected as an object. In such cases, the adjacent lane width Llane would be detected (treated) as Llane=L. 
     Namely, objects inside the lane boundary line  88  (on the adjacent lane  87  side, within the adjacent lane  87 ), objects outside the lane boundary line  88  (on the roadside  89  side), and objects straddling the lane boundary line  88  are all candidates for the object  90  detected or identified in the detection range  83 . Note that fundamentally, such objects are objects moving in the direction of progress of the vehicle  10  at a slower velocity than the velocity of the vehicle  10 , objects moving in the opposite direction, or stationary objects. 
     Next, at step S 7 , as illustrated in  FIG. 4A  and  FIG. 4B , a target position  102  for changing lanes is set in the adjacent lane  87 . The target position  102  in the adjacent lane  87  is set in order to calculate an offset distance Doff in the lane width direction Y from the lane width direction Y position (current position) in the current lane  85  to the lane width direction Y target position  102  in the adjacent lane  87 . 
     Note that in cases in which an object  90  has not been detected in the adjacent lane  87 , or cases in which an object  90  has been detected at the roadside  89 , the target position  102  is set to a position at half the distance L/2 of the adjacent lane width Llane=L. In cases in which an object  90  has been detected in the adjacent lane  87 , as illustrated in  FIG. 4B , the target position  102  is set to a position at half the distance L/2 of the adjacent lane width Llane=L or a position at half the distance Lob/2 of the adjacent lane width Llane=Lob. 
     Next, at step S 8 , determination is made as to whether or not an object  90  is present in the direction of the adjacent lane  87 , this being the lane change target lane. 
     In cases in which it has been confirmed that there is no object present in the lane change target lane  87  or in the vicinity of the lane change target lane  87  (step S 8 : NO), as illustrated in  FIG. 4A , at step S 9 , the lane change path command Tcom is calculated as normal. 
     However, in cases in which, as illustrated in  FIG. 4B , the presence of an object  90  is confirmed in the adjacent lane  87 , this being the lane change target lane, or in the vicinity of the lane change target lane  87  at step S 8  (although not illustrated in the drawings, this includes cases in which an object is present at the roadside  89  in the state illustrated in  FIG. 4A ) (step S 8 : YES), then at step S 10 , as illustrated in  FIG. 5A , a maximum lateral acceleration Aymax′ of the vehicle  10  in the lane width direction Y is calculated for the detected adjacent lane width Llane=L, Lob by referring to the characteristics  81  for the maximum lateral acceleration Aymax of the vehicle  10  in the lane width direction Y with respect to the adjacent lane widths Llane=L, Lob respectively illustrated in  FIG. 4A  and  FIG. 4B . 
     Alternatively, at step S 10 , as illustrated in  FIG. 5B , a maximum lateral velocity Vymax′ of the vehicle  10  in the lane width direction is calculated for the detected adjacent lane width Llane=L, Lob by referring to the characteristics  82  the for the maximum lateral velocity Vymax of the vehicle  10  in the lane width direction with respect to the adjacent lane widths Llane=L, Lob respectively illustrated in  FIG. 4A  and  FIG. 4B . 
     Next, at step S 11 , the object determination section  44  classifies the type of the object  90  detected in the surrounding environment by the lane marking/object detection section  42 . Specifically, at step S 11 , the object  90  confirmed within the lane change target lane  87  or in the vicinity of the adjacent lane  87  (including at the roadside  89 ) is classified with an object type ID indicating whether the object  90  is an animal or an object other than an animal (a pedestrian, a bicycle being pedaled by a cyclist, a stationary vehicle (no possibility of door opening), or a stationary vehicle (possibility of door opening)). 
     When determining between a stationary vehicle in which there is no possibility that a door could open (no possibility of door opening) and a stationary vehicle in which there is a possibility that a door could open (possibility of door opening), there is determined to be a possibility of an occupant opening a door of the stationary vehicle and exiting the stationary vehicle in cases in which the vehicle  10  detects that that the engine of the stationary vehicle has been switched from an ON state to an OFF state, or in cases in which the vehicle  10  detects that the stationary vehicle has only just entered the OFF state, for example through inter-vehicle communication with the stationary vehicle using the communication device  37 . 
     At step S 11 , in cases in which the object  90  is an animal such as a deer and the object type ID is classified as ID=ex, the subsequent steps S 12  and step S 9  (lane change path generation steps) are skipped and the lane change path command Tcom is not generated, since the behavior of animals is generally difficult to predict. Note that similarly to in cases in which the object  90  is an animal, the ID=ex is also applied in cases in which the type ID of the object  90  cannot be classified, and step S 12  and step S 9  (lane change path generation steps) are skipped and the lane change path command Tcom is not generated. However, configuration may be made such that in cases in which an animal has been identified specifically, only step S 12 , described later, is skipped, and the lane change path command Tcom may be generated at step S 9  based on the result of step S 10 . 
     In the determination at step S 11 , in cases in which the object  90  is classified with a type ID of an object other than an animal (a pedestrian, a bicycle being pedaled by a cyclist, or a stationary vehicle), a type ID=1 is applied to a bicycle being pedaled by a cyclist, a type ID=2 is applied to a pedestrian, a type ID=3 is applied to a stationary vehicle (no possibility of door opening), and a type ID=4 is applied to a stationary vehicle (possibility of door opening). 
     Next, at step S 12 , a table (map)  100  of reduction ratios for the maximum lateral acceleration Aymax′ or the maximum lateral velocity Vymax′ corresponding to the object type IDs illustrated in  FIG. 6  is referenced. 
     If the reduction ratio for the type ID=1 for a bicycle being pedaled by a cyclist is ratio 1 , the reduction ratio for the type ID=2 for a pedestrian is ratio 2 , the reduction ratio for the type ID=3 for a stationary vehicle (no possibility of door opening) is ratio 3 =1 (value 1), and the reduction ratio for the type ID=4 for a stationary vehicle (possibility of door opening) is ratio 4 , then the applied values have the relationship 0&lt;ratio 1 &lt;ratio 2 &lt;ratio 4 &lt;ratio 3 =1. 
     At step S 12 , a maximum lateral acceleration AymaxID′ after reducing the maximum lateral acceleration Aymax of the vehicle  10  in the lane width direction Y, or a maximum lateral velocity VymaxID′ after reducing the maximum lateral velocity Vymax of the vehicle  10  in the lane width direction, is calculated according to the object type ID classified at step S 11 , using the respective Equations 3 and 4 below. 
     In Equation 3 and Equation 4, the functions Fa(ID) and Fv(ID) are functions that, based on  FIG. 6 , determine a reduction ratio called ratio to reduce the lateral acceleration Aymax′ or the lateral velocity Vymax′ calculated using the characteristics  81  or the characteristics  82  respectively illustrated in  FIG. 5A  and  FIG. 5B .
 
 Ay maxID′= Fa (ID)× Ay max′  (3)
 
 Vy maxID′= Fv (ID)× Vy max′  (4)
 
     Accordingly, the reduced maximum lateral acceleration AymaxID′ and the reduced maximum lateral velocity VymaxID′ are calculated according to the classified object type ID in the following manner. 
     
       
         
           
               
               
               
             
               
                   
               
             
            
               
                 Bicycle 
                 ID = 1 
                 Aymax1′ = ratio1 × Aymax′ 
               
               
                   
                   
                 Vymax1′ = ratio1 × Vymax′ 
               
               
                 Pedestrian 
                 ID = 2 
                 Aymax2′ = ratio2 × Aymax′ 
               
               
                   
                   
                 Vymax2′ = ratio2 × Vymax′ 
               
               
                 Stationary vehicle 
                 ID = 3 
                 Aymax3′ = ratio3 × Aymax′ = Aymax′ 
               
               
                 (no possibility of door 
                   
                 Vymax3′ = ratio3 × Vymax′ = Vymax′ 
               
               
                 opening) 
               
               
                 Stationary vehicle 
                 ID = 4 
                 Aymax4′ = ratio4 × Aymax′ 
               
               
                 (possibility of door 
                   
                 Vymax4′ = ratio4 × Vymax′ 
               
               
                 opening) 
               
               
                   
               
            
           
         
       
     
     Next, at step S 12 , the lane change path command Tcom is generated based on the reduced maximum lateral acceleration AymaxID′ or the reduced maximum lateral velocity VymaxID′, together with the velocity or acceleration of direction X and the offset distance Doff. 
       FIG. 7  is a plan view schematically illustrating examples of lane change path commands Tcom= 91  (ID 1 ),  92  (ID 2 ),  93  (ID 3 ), and  94  (ID 4 ) generated according to the object type ID for cases in which an object  90  has been detected in the adjacent lane  87 . 
     The lane change path command Tcom= 91  (ID 1 ) is calculated in cases in which the object  90  is a bicycle being pedaled by a cyclist. The lane change path command Tcom= 92  (ID 2 ) is calculated in cases in which the object  90  is a pedestrian. The lane change path command Tcom= 93  (ID 3 ) is calculated in cases in which the object  90  is a stationary vehicle (no possibility of door opening). The lane change path command Tcom= 94  (ID 4 ) is calculated in cases in which the object  90  is a stationary vehicle (possibility of door opening). Namely, the lane change path command Tcom is calculated appropriately and accurately according to the type ID of the object  90 . 
     Thereafter, in lateral velocity VymaxID′ control, the lane change controller  46  performs automatic lane change control by controlling the steering angle of the steering device  62  according to the calculated lane change path command Tcom. In lateral acceleration AymaxID′ control, the lane change controller  46  performs automatic lane change control by controlling the steering angle of the steering device  62  and controlling to increase the drive force of the drive device  64  according to the calculated lane change path command Tcom. 
     Summary of Embodiment 
     The lane change control system  12  according to the embodiment described above includes the surrounding environment sensors  30  and the like as a surrounding environment acquisition section that acquires the surrounding environment at least in front of the vehicle  10 , the lane marking/object detection section  42  that detects lane markings and an object  90  in the acquired surrounding environment, the lane change controller  46  that controls lane changing of the vehicle  10  according to the lane markings and object  90  detected, and the object determination section  44  that determines whether or not the object  90  detected in the surrounding environment is present in the lane change target adjacent lane  87  or in the vicinity of the adjacent lane  87 . 
     Here, when the detected object  90  has been determined to be an object  90  present in the lane change target adjacent lane  87  or in the vicinity of the adjacent lane  87 , the lane change controller  46  performs lane change control using the predetermined maximum lateral acceleration Aymax′ with respect to the lane width Llane=L, Lob of the lane change target lane (adjacent lane)  87  illustrated in  FIG. 5A , or using the predetermined maximum lateral velocity Vymax′ with respect to the lane width Llane=L, Lob of the lane change target lane (adjacent lane)  87  illustrated in  FIG. 5B . 
     In this manner, in cases in which the object  90  detected by the lane marking/object detection section  42  is determined to be an object  90  present in the lane change target lane  87  or in the vicinity of the adjacent lane  87 , lane change control is performed in which the predetermined maximum lateral acceleration Aymax′ or maximum lateral velocity Vymax′ is reduced according to the lane width Llane=L, Lob of the adjacent lane  87 . Accordingly, it is possible to avoid alarming an occupant of the vehicle  10  attempting to change from a current position  101  in the lane  85  to the target position  102  in the adjacent lane  87 . 
     Here, the object determination section  44  includes functionality to classify the type ID of the detected object  90 . Accordingly, the lane change controller  46  is capable of setting an appropriate reduction ratio ratio for the maximum lateral acceleration Aymax′ or the maximum lateral velocity Vymax′ according to the classified type ID of the object  90  by changing the reduction ratio ratio so as to reduce the maximum lateral acceleration Aymax′ or the maximum lateral velocity Vymax′ according to the classified type ID of the object  90 . 
     More specifically, when the detected object  90  is a person, namely a pedestrian, and the type ID is classified as ID=2, the lane change controller  46  changes the reduction ratio ratio such that the maximum lateral acceleration Aymax′ or the maximum lateral velocity Vymax′ becomes smaller than for an object  90  other than a person, namely the stationary vehicle (no possibility of door opening) ID=3 and the stationary vehicle (possibility of door opening) ID=4 in the present embodiment (ratio 2 &lt;ratio 3 , ratio 4 ). This thereby avoids alarming the person present in the adjacent lane  87  or in the vicinity of the adjacent lane  87  into which the vehicle  10  is attempting to change, and at the same time, avoids alarming occupants of the vehicle  10  that is attempting to change from the lane  85  to the lane  87 . 
     Note that when the person who has been detected and classified is riding a bicycle (a cyclist pedaling a bicycle), the reduction ratio ratio is changed from the ratio 2  to the ratio 1  such that the maximum lateral acceleration Aymax 2 ′ or the maximum lateral velocity Vymax 2 ′ becomes smaller than when using the reduction ratio ratio 2  for a pedestrian (becomes the maximum lateral acceleration Aymax 1 ′ or the maximum lateral velocity Vymax 1 ′). This thereby avoids alarming the person riding a bicycle (cyclist pedaling a bicycle) present in the adjacent lane  87  or in the vicinity of the adjacent lane  87  into which the vehicle  10  is attempting to change, and at the same time, avoids alarming occupants of the vehicle  10  that is attempting to change from the lane  85  to the adjacent lane  87 . Note that a bicycle being pedaled by a cyclist has a greater sideways wobble with respect to the direction of progress than a pedestrian. 
     Since a stationary vehicle (no possibility of door opening) has no sideways wobble with respect to the direction of progress, the reduction ratio ratio 3  is set to ratio 3 =1. However, the reduction ratio is changed to the reduction ratio ratio 4  (ratio 4 &lt;ratio 3 ) for a stationary vehicle (possibility of door opening), such that the maximum lateral acceleration Aymax′ or the maximum lateral velocity Vymax′ becomes smaller than when employing the reduction ratio ratio 3  for a stationary vehicle (no possibility of door opening), in consideration of the fact that an occupant may exit the stationary vehicle. Setting in this manner enables the maximum lateral acceleration Aymax 4 ′ or the maximum lateral velocity Vymax 4 ′ to be set using the reduction ratio ratio 4  that is more appropriate for a stationary vehicle when there is a possibility of the door opening. 
     Note that as illustrated in  FIG. 2A  and  FIG. 5A , and in  FIG. 2B  and  FIG. 5B , the predetermined maximum lateral acceleration Aymax (Aymax′) or maximum lateral velocity Vymax (Vymax′) is set with smaller values the narrower the lane change target lane width Llane. This thereby enables the change from the lane  85  to the lane change target adjacent lane  87  to be controlled at an appropriate speed that neither alarms the occupant, nor feels slow to the occupant. 
     In this manner, in the present embodiment, lane change control is performed based on the adjacent lane information Llaneinfo combining the adjacent lane width Llane information and the adjacent object information Obinfo. This thereby enables lane change control to be performed appropriately, without alarming the occupant of the vehicle  10 , or the other person in cases in which the object  90  is a pedestrian or the like. 
     Note that the present disclosure is not limited to the embodiment described above, and obviously various configurations may be adopted based on the contents of the present specification. 
     For example, the object type is classified at step S 11  described above. However, there is no limitation thereto, and the type of the object  90  may be classified earlier when determining the presence or absence of the object  90  at step S 8 . 
     Configuration may be made such that steps S 10 , S 11 , and S 12  are skipped so as to proceed to step S 9  (lane change path generation) and calculate the lane change path command Tcom as normal in cases in which an object (static roadside object) has been determined to be present (step S 8 : YES) and has been determined to be a static roadside object present at the roadside  89 , such as guard rail or a pole, as a result of earlier classification of the object  90  type. 
     In cases in which the object  90  has been determined to be a bicycle, pedestrian, stationary vehicle, or animal as a result of the earlier classification of the object  90  type, processing transitions to step S 10  and S 11 , and the reduction ratio is selected according to the object type. 
     This thereby enables unnecessary control (steps S 10 , S 11 , S 12 ) to be omitted for stationary roadside objects that do not pose an obstacle to normal lane changing, since the occupant would not be alarmed even were normal lane changing to be performed.