Patent Publication Number: US-2022227387-A1

Title: Vehicle control device

Description:
TECHNICAL FIELD 
     The present invention relates to a vehicle control device that performs driving assistance. 
     BACKGROUND ART 
     In the related art, there has been known a vehicle control device that stores a route on which a host vehicle travels, and surrounding environment information on an object or a white line around the host vehicle and then controls the vehicle by using the stored surrounding environment information, in order to realize an autonomous driving system or a parking assistance system of a vehicle (see PTL 1, for example). 
     Examples of the surrounding environment information of the host vehicle include position information regarding an object such as a stationary object and a moving object around the host vehicle, road marks (road marking paint) such as white lines and stop lines on the road, and external surrounding situations such as traffic lights and speed signs around the road. 
     The vehicle control device needs to determine whether the object is a stationary object or a moving object, and detect information such as a position and a speed of the object. In addition, it is necessary to determine a position of a white line on a road on which the host vehicle travels and a meaning of a sign. 
     Therefore, a vehicle sensor is required to detect the surrounding environment information of the host vehicle. As the vehicle sensor, a camera using an image recognition technique, a sonar using an ultrasonic technique, and a millimeter wave radar using a radio wave having a short wavelength are effective. 
     In addition, a route on which the host vehicle has traveled can be calculated by acquiring information of the host vehicle position. A method of acquiring the host vehicle position varies depending on a configuration of a system. A method called dead reckoning is known in which the host vehicle position is estimated by using host vehicle sensor information of a wheel speed sensor, a steering angle sensor, an acceleration sensor, a gyro sensor, and the like. 
     CITATION LIST 
     Patent Literature 
     
         
         PTL 1: JP 2016-99635 A 
       
    
     SUMMARY OF INVENTION 
     Technical Problem 
     However, the detection performance of the vehicle sensor may change depending on a speed range of the host vehicle. Specifically, regarding detection of an object around the host vehicle, a position of a white line, and sign contents, erroneous detection or non-detection increases. 
     For example, a sonar or a monocular camera that detects information in the vicinity of a vehicle has a limited vehicle speed range allowing detection with high accuracy, due to a relation of a detection range. In addition, the millimeter wave radar has less change in the detection accuracy depending on the vehicle speed range, but the shape accuracy of an object is lower than that of the sonar. 
     In addition, in the sonar and the millimeter wave radar, transmission waves are irregularly reflected due to cracks, unevenness, or the like of a road surface. Thus, accurate acquisition of a reception wave may not be possible. In the case of a low vehicle speed range, such a phenomenon remarkably occurs, and thus, an error occurs in recognition accuracy. 
     In addition, depending on the vehicle speed range of the host vehicle, a slip angle is generated due to deflection of a tire, and thus sideslip occurs. In the dead reckoning of a host vehicle position estimation method, a movement distance and a yaw angle are calculated and sequentially integrated by using sensor information of the host vehicle. Thus, an error occurs between the accuracy of the position of the host vehicle that has skidded and the accuracy of the host vehicle estimation position due to the dead reckoning. 
     The present invention has been made in view of the above problems, and an object of the present invention is to reduce various errors by notifying a user so as to adjust a vehicle speed to a vehicle speed causing the accuracy of the vehicle sensor and the host vehicle position estimation method to be improved, when surrounding environment information is stored, and controlling the vehicle speed to the vehicle speed causing the accuracy of the vehicle sensor and the host vehicle position estimation method to be improved, when autonomous driving is performed. 
     Solution to Problem 
     According to the present invention, a vehicle control device that includes a processor and a memory and controls traveling of a vehicle includes 
     a sensor that acquires surrounding environment information of the vehicle, 
     a host vehicle position estimation unit that estimates a traveling route of the vehicle, 
     a surrounding environment storage unit that stores the surrounding environment information acquired by the sensor and the traveling route estimated by the host vehicle position estimation unit in association with each other, 
     a vehicle-speed threshold determination unit that sets a vehicle-speed threshold value when the surrounding environment storage unit stores the surrounding environment information and the traveling route in association with each other, and determines whether or not a current vehicle speed exceeds the vehicle-speed threshold value when the surrounding environment storage unit stores the surrounding environment information and the traveling route, and 
     a warning unit that performs a notification of an excess of the vehicle speed when the vehicle-speed threshold determination unit determines that the vehicle speed exceeds the vehicle-speed threshold value. 
     Advantageous Effects of Invention 
     Thus, according to the present invention, when the surrounding environment information is stored, it is possible to perform a notification so as to obtain a vehicle speed range causing the accuracy of the vehicle sensor and the host vehicle position estimation method to be improved. Further, when driving of the vehicle is assisted, it is possible to set a vehicle speed at which the accuracy of the surrounding environment information and the accuracy of the host vehicle position estimation method are improved. 
     Objects, configurations, and advantageous effects other than those described above will be clarified by the descriptions of the following embodiments. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a block diagram illustrating an embodiment of the present invention and illustrating an example of a vehicle to which the present invention is applied. 
         FIG. 2  is a block diagram illustrating the embodiment of the present invention and illustrating an example of functions of a vehicle control device to which the present invention is applied. 
         FIG. 3  is a diagram illustrating the embodiment of the present invention and illustrating an example of a recognition region by an image pickup sensor and a short distance measuring sensor mounted on the vehicle. 
         FIG. 4  is a diagram illustrating the embodiment of the present invention and illustrating an example of a recognition region by a middle distance measuring sensor and a long distance measuring sensor mounted on the vehicle. 
         FIG. 5  is a diagram illustrating the embodiment of the present invention and illustrating an example of a mechanism in which an error occurs between a host vehicle estimation position and an actual vehicle position during circle turning, depending on a vehicle speed range. 
         FIG. 6  is a diagram illustrating the embodiment of the present invention and illustrating an example of a mechanism in which deflection of a tire occurs. 
         FIG. 7  is a diagram illustrating the embodiment of the present invention and illustrating an example of a mechanism in which an error occurs in recognition accuracy due to a crack or unevenness of a road surface. 
         FIG. 8  is a diagram illustrating the embodiment of the present invention and illustrating an example of a surrounding environment of a vehicle. 
         FIG. 9  is a diagram illustrating the embodiment of the present invention and illustrating an example of a screen output to a display device when surrounding environment information of a vehicle is stored. 
         FIG. 10  is a diagram illustrating the embodiment of the present invention and illustrating an example of a screen display in a case where a vehicle speed exceeds a vehicle-speed threshold value when a vehicle travels to a target position by manual driving. 
         FIG. 11  is a diagram illustrating the embodiment of the present invention and illustrating an example of a screen display in a case where the vehicle speed exceeds the vehicle-speed threshold value for a predetermined time when the surrounding environment information of a vehicle is stored. 
         FIG. 12  is a diagram illustrating the embodiment of the present invention and illustrating an example of a screen display output to the display device when autonomous driving is performed to the target position by using the stored surrounding environment information. 
         FIG. 13  is a graph illustrating the embodiment of the present invention and illustrating a relation between the vehicle speed, a remaining distance, and a time at a point where the vehicle speed is changed on a traveling route. 
         FIG. 14  is a flowchart illustrating the embodiment of the present invention and illustrating an example of processing performed by the vehicle control device during the manual driving. 
         FIG. 15  is a flowchart illustrating the embodiment of the present invention and illustrating an example of processing performed by the vehicle control device during the autonomous driving. 
         FIG. 16  is a diagram illustrating the embodiment of the present invention and illustrating an example in which, when the surrounding environment information of a vehicle is used, a user who has executed storing processing is specified, and information is acquired from the outside of the vehicle control device. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, an embodiment of a vehicle to which a vehicle control device according to the present invention is applied will be described with reference to the drawings.  FIG. 1  is a block diagram illustrating a configuration of a vehicle according to the present invention. A vehicle  1  illustrated is a rear-wheel drive vehicle that includes a cylinder injection type gasoline engine  11 , for example, as a traveling power source, an automatic transmission  12  that transfers a driving force from the gasoline engine  11 , a propeller shaft  13 , a differential gear  14 , a drive shaft  15 , a brake device  20  including four tires  16  and a wheel speed sensor, and an electric power steering  21 . 
     In the vehicle  1 , devices, actuators, and instruments including a vehicle control device  50  and various sensors described later transmit and receive signals and data to and from each other through in-vehicle LAN or CAN communication. The vehicle control device  50  acquires information on the outside of the vehicle  1  from sensors described later. The vehicle control device  50  transmits command values for realizing control such as automatic parking (driving assistance) and autonomous driving, to the gasoline engine  11 , the brake device  20  including the wheel speed sensor, the electric power steering  21 , and the automatic transmission  12 . The wheel speed sensor generates a pulse waveform in accordance with the rotation of the wheel, and transmits the pulse waveform to the vehicle control device  50 . 
     A plurality of image pickup sensors  17  and a plurality of short distance measuring sensors  24  are disposed in front of, behind, and on sides of the vehicle  1 . In addition, middle distance measuring sensors  22  are disposed in front of and behind the vehicle  1 . A long distance measuring sensor  23  is disposed in front of the vehicle. These sensors detect objects around the vehicle  1  and a road environment such as a white line, and supply the road environment to the vehicle control device  50 . The mounting positions of these sensors and the number of various sensors are not limited to those in  FIG. 1 . 
     The illustrated vehicle  1  is an example of a vehicle to which the present invention can be applied, and the present invention does not limit the configuration of the applicable vehicle. For example, a vehicle adopting a continuously variable transmission (CVT) instead of the automatic transmission  12  may be used. A vehicle including a motor instead of the gasoline engine  11  being the traveling power source or a vehicle including an engine and a motor as the traveling power source may be used. 
       FIG. 2  is a functional block diagram of a vehicle control system to which the present invention is applied. The vehicle control system illustrated in  FIG. 2  is mounted on the vehicle  1 . The vehicle control system includes the image pickup sensor  17 , the short distance measuring sensor  24 , the middle distance measuring sensor  22 , the long distance measuring sensor  23 , an input switch unit  34 , a wheel speed sensor  35 , a position detector  36 , a communication device  37 , a various-sensor/actuator ECU  40  of the vehicle, a warning device  41 , and the vehicle control device  50  connected to these components. 
     The vehicle control device  50  includes a processor  2  and a memory  3 . In the vehicle control device  50 , the respective programs of a host vehicle position estimation unit  51 , a surrounding environment storage unit  52 , a vehicle-speed threshold determination unit  53 , a stored-information collation unit  54 , a vehicle-speed calculation unit  55 , an external-recognition-information conversion unit  56 , and a vehicle control unit  57  are loaded into the memory  3  and executed by the processor  2 . 
     The processor  2  executes processing in accordance with a program of each functional unit to run as the functional unit that provides a predetermined function. For example, the processor  2  executes processing in accordance with a host vehicle position estimation program to function as the host vehicle position estimation unit  51 . The same applies to other programs. Further, the processor  2  also runs as a functional unit that provides each function in a plurality of pieces of processing executed by the respective programs. A computer and a computer system are a device and a system including such functional units. 
     The image pickup sensor  17  can be configured by, for example, a camera. The image pickup sensor  17  is used to pick up information of an object, a white line, or a sign by an imaging element attached around the vehicle  1 . In the example illustrated in  FIG. 2 , one camera is used, but a stereo camera having two cameras may be used. 
     Image pickup data by the image pickup sensor  17  can be synthesized and processed like, for example, an overhead image representing a form viewed from a virtual viewpoint above the vehicle  1  capable of displaying the surroundings of the vehicle  1 . The image pickup data by the image pickup sensor  17  is input to the vehicle control device  50 . 
     The short distance measuring sensor  24  can be configured by, for example, a sonar. The short distance measuring sensor  24  is used to detect a distance from an object near the vehicle  1  by transmitting an ultrasonic wave toward the surroundings of the vehicle  1  and receiving the reflected wave. Distance measurement data by the short distance measuring sensor  24  is input to the vehicle control device  50 . 
     The middle distance measuring sensor  22  can be configured by, for example, a millimeter wave radar. The middle distance measuring sensor  22  is used to detect a distance from an object by transmitting a high-frequency wave called a millimeter wave toward the surroundings of the vehicle  1  and receiving the reflected wave. Distance measurement data by the middle distance measuring sensor  22  is input to the vehicle control device  50 . 
     The long distance measuring sensor  23  can be configured by, for example, a millimeter wave radar. The long distance measuring sensor  23  is used to detect a distance from an object by transmitting a high-frequency wave called a millimeter wave toward the front of the vehicle  1  and receiving the reflected wave. The long distance measuring sensor  23  is not limited to a millimeter wave radar, and may be configured by a stereo camera or the like. Distance measurement data by the long distance measuring sensor  23  is input to the vehicle control device  50 . 
     The input switch unit  34  is, for example, a dedicated mechanical switch provided around a driver seat  413 . The input switch unit  34  may be a graphical user interface (GUI) switch or the like. The input switch unit  34  receives an instruction to store surrounding environment information or an instruction to automatically control the vehicle, by an operation of a user (driver). 
     The wheel speed sensor  35  includes a sensor and a controller. The sensor is attached to each wheel of the vehicle  1  and detects a rotation speed of the wheel. The controller generates a vehicle speed signal by integrating detection values detected by the sensors. Vehicle speed signal data from the wheel speed sensor  35  is input to the vehicle control device  50 . 
     The position detector  36  includes an azimuth sensor that measures an azimuth in front of the vehicle  1 , a global positioning system (GPS) receiver for a GPS that measures the position of the vehicle based on a radio wave from a satellite, and the like. 
     The communication device  37  is a device that exchanges communication from the outside. For example, the communication device  37  acquires road surface information (road marking paint type and position such as a lane marker position, a stop line position, and a crosswalk) and object information (object around a road, such as a sign, a traffic light, or a feature), as road information around the vehicle  1 . As will be described later, regarding such information, information detected by a sensor installed in the road infrastructure, road surrounding information (road surface information, object information, and the like) stored in an external data center, and road surrounding information (road surface information, object information, and the like) detected by another vehicle can also be acquired by using the communication device  37 . Furthermore, the road surrounding information stored in advance can be changed to the latest information by using the communication device  37 . 
     The various-sensor/actuator ECU  40  may be known or well-known, and includes, for example, a power steering ECU and a brake ECU. 
     The vehicle control unit  57  includes, as control targets, a driving force  571 , a braking force  572 , a steering angle  573  for controlling a course of the vehicle  1 , a traveling direction  574  of the vehicle  1 , and the like. 
     The warning device  41  notifies the user of an excess of the vehicle speed determined by the vehicle-speed threshold determination unit  53  described later. For example, the user is notified of the excess of the speed by using a display device  411  such as a liquid crystal display, a sound output device  412  such as a speaker, the driver seat  413  including a vibrator, or the like. 
     The host vehicle position estimation unit  51  calculates and estimates the position where the vehicle  1  travels, from information output by the position detector  36  and the wheel speed sensor  35 , for example. 
     The vehicle-speed calculation unit  55  detects the traveling speed of the vehicle  1  from a signal output from the wheel speed sensor  35 , and outputs a vehicle speed signal indicating the detected traveling speed to the vehicle control device  50 . 
     When the surrounding environment information is stored, the vehicle-speed threshold determination unit  53  determines whether or not the vehicle speed controlled by the user exceeds an upper limit value of the vehicle speed predetermined by the vehicle control device  50 . 
     The external-recognition-information conversion unit  56  converts the surrounding environment information acquired when the vehicle travels by manual driving, by using the image pickup sensor  17 , the short distance measuring sensor  24 , the middle distance measuring sensor  22 , and the long distance measuring sensor  23 , and the positional relation of the vehicle  1  output from the host vehicle position estimation unit  51  into a predetermined coordinate system. 
     The surrounding environment storage unit  52  stores the surrounding environment information transformed into the predetermined coordinate system by the external-recognition-information conversion unit  56  and data obtained by transforming the positional (traveling route) relation of the vehicle  1  into the predetermined coordinate system. The host vehicle position estimation unit  51  estimates the position of the host vehicle at a predetermined cycle. The surrounding environment storage unit  52  stores data obtained by connecting the estimated positions in time series as a traveling route. 
     Position information of the vehicle  1  of the host vehicle position estimation unit  51  corresponding to the surrounding environment information stored in the surrounding environment storage unit  52  is input to the stored-information collation unit  54 . The stored-information collation unit  54  collates information of the surrounding environment of the vehicle  1  detected by various sensors mounted on the vehicle  1  with the stored information, and calculates and compares the feature amount whether the target object corresponding to the stored information coincides. 
     The stored-information collation unit  54  calculates and compares the feature amount of the target object stored in the surrounding environment storage unit  52  and the feature amount of the detected target object in the surrounding environment of vehicle  1 . A known or well-known method may be applied to the calculation of the feature amount. 
     When the degree of the feature amounts coinciding with each other is high, the stored-information collation unit  54  transitions to a low-speed autonomous driving possible state. When the degree of the feature amounts coinciding with each other is low, the stored-information collation unit  54  transitions to a low-speed autonomous driving impossible state. 
     The vehicle control unit  57  calculates target values for controlling the various-sensor/actuator ECU  40  when performing the low-speed autonomous driving, and outputs a control instruction. The target values calculated by the vehicle control unit  57  include the driving force  571 , the braking force  572 , the steering angle  573 , and the traveling direction  574 . 
       FIG. 3  is a diagram illustrating an example of arrangement and detection ranges of the short distance measuring sensors  24 A to  24 L and the image pickup sensors  17 A to  17 D mounted on the front portion, the side portion, and the rear portion of the vehicle  1 . 
     As illustrated in  FIG. 3 , six short distance measuring sensors  24 A,  24 B,  24 C,  24 D,  24 E, and  24 F in total are disposed in front of the vehicle  1 , and six short distance measuring sensors  24 G,  24 H,  24 I,  24 J,  24 K, and  24 L in total are disposed behind the vehicle  1 . An ellipse indicated by a dotted line in  FIG. 3  indicates an example of a detection range of each of the short distance measuring sensors  24 A to  24 L. 
     As illustrated in  FIG. 3 , the image pickup sensor  17 A is attached to the front of the vehicle  1 . The image pickup sensors  17 B and  17 C are attached to the left and right of the vehicle  1 . The image pickup sensor  17 D is attached to the rear of the vehicle  1 . 
     A straight broken line illustrated in  FIG. 3  indicates an example of a detection range of each of the image pickup sensors  17 A to  17 D. By converting and combining images picked up by the four image pickup sensors  17 A to  17 D, it is possible to generate an overhead view of the vehicle  1  and the surroundings of the vehicle  1  viewed from above. The overhead view is used for display on a liquid crystal display (display device  411 ) or the like. 
       FIG. 4  is a diagram illustrating an example of the arrangement and detection ranges of the middle distance measuring sensors  22 A to  22 D mounted on the front portion and the rear portion of the vehicle  1  and the long distance measuring sensor  23  mounted on the front portion of the vehicle  1 . 
     As illustrated in  FIG. 4 , the middle distance measuring sensors  22 A to  22 B are disposed in the front portion of the vehicle  1 , and the middle distance measuring sensors  22 C to  22 D are disposed in the rear portion of the vehicle  1 . A fan shape indicated by a dotted line in  FIG. 3  indicates an example of a detection range of each of the middle distance measuring sensors  22 A to  22 D. 
     As illustrated in  FIG. 4 , the long distance measuring sensor  23  is disposed in the front portion of the vehicle  1 . A fan shape indicated by a broken line in  FIG. 4  indicates an example of a detection range of the long distance measuring sensor  23 . 
       FIG. 5  is a diagram illustrating a movement trajectory of the vehicle  1  by a change in a vehicle speed range when the vehicle travels in a steady circle.  FIG. 5  illustrates a vehicle  1   a  at a position after the vehicle  1  travels by a certain distance. A solid line indicates a target route trajectory  501 . A long two-dot chain line indicates a trajectory  502  during low-speed traveling. A long broken line indicates a trajectory  503  during high-speed traveling. 
     In  FIG. 5 , the deflection of the tire  16  hardly occurs during the low-speed traveling, and thus the vehicle can track the target route trajectory  501 . However, the deflection of the tire  16  occurs during the high-speed traveling, and thus, even though the steering angle is the same, it is not possible for the vehicle to track the target route trajectory  501 , and an error occurs. Although the target route trajectory  501  and the trajectory  502  during the low-speed traveling coincide with each other, the trajectories  501  and  502  are shifted in terms of notation in  FIG. 5 . 
       FIG. 6  is a diagram illustrating a deflection change of the tire  16 . The tire  16  is deflected by a frictional force generated by a contact with a road surface and a lateral force (lateral load in  FIG. 6 ) during turning. The larger the load, the larger the deflection amount. During the high-speed traveling illustrated in  FIG. 5 , the load on the tire  16  increases, so that the deflection occurs, it is not possible for the vehicle to track the target route trajectory  501 , and an error occurs. 
       FIG. 7  illustrates an example in which a crack or unevenness of the road surface is provided in the surrounding environment information. As the surrounding environment information of the vehicle  1 , there are a white line  109 , a crack  601 , and road-surface unevenness  600 . A sonar or a millimeter wave radar transmits an ultrasonic wave or a millimeter wave to an object, and measures a distance based on a time when a reflected wave hitting the object is received. However, in the case of a crack or unevenness of a road surface, a reflected wave bouncing back is irregularly reflected, and thus it is not possible to accurately acquire a reception wave. In the case of a low vehicle speed range, such a phenomenon remarkably occurs, and thus, an error occurs in recognition accuracy. 
       FIGS. 8, 9, 10, and 11  are explanatory diagrams regarding a case where environment information on the surroundings of the vehicle  1  is stored by manual driving and the vehicle  1  autonomously travels to a target position by using the stored surrounding environment information, as an example of a travel scene regarding a travel control system in the present embodiment. Here, the target position indicates a parking position, a stop position, and the like. The target position may be set in advance from an input device such as the input switch unit  34 . Alternatively, in the case of the display device  411  including a touch panel, the target position may be set by displaying map information on a screen. 
       FIG. 8  is a diagram illustrating an example of the surrounding environment information of the vehicle  1 . As the surrounding environment information of the vehicle  1 , there are a utility pole  104 , a traffic light  105 , a crosswalk  106 , a sign  107 , a road marking paint  108 , a white line  109 , and the like present beside the road. In addition, another vehicle  102 , an outer wall  110 , and the like are present around a house  103 . In addition, the surrounding environment information may include the above-described road surrounding information (road surface information and object information). 
     Points m 1 , m 2 , and m 3  in  FIG. 8  indicate points where the speed of the vehicle  1  is changed in  FIG. 13  described later. 
     As information necessary for autonomous traveling of the vehicle  1 ,  FIG. 8  illustrates a route  111  during manual driving, and  FIG. 12  illustrates a target route  112  during autonomous driving. 
     A moving object around the vehicle  1  changes from moment to moment, but in general, the road marking paint  108 , the sign  107  around the road, the traffic light  105 , and the like are considered to be target objects that normally exist so long as the target objects are not updated or modified. The positions of the road marking paint  108 , the sign  107 , and the traffic light  105 , which are such target objects that normally exist, are stored in the surrounding environment storage unit  52 , as information on the map. 
       FIG. 9  is a diagram illustrating a display example of a screen  420  in which the surrounding environment information is being stored when the surrounding environment information is stored by manual driving.  FIG. 9  illustrates an example of the screen  420  displayed on the display device  411 . 
     The screen  420  includes a window  421  for displaying an image of the front of the vehicle  1  picked up by the image pickup sensor  17 A, and a window  422  for displaying an image of the vehicle  1  viewed from above, which is obtained by combining images picked up by the image pickup sensors  17 A to  17 D. 
     In the flowchart of  FIG. 14  described later, the screen  420  in  FIG. 9  shows processing contents of Step S 104 . 
       FIG. 10  is a diagram illustrating a display example of the screen  420  for giving a notification to reduce the vehicle speed in a case where the speed of the vehicle  1  exceeds a vehicle-speed threshold value when the surrounding environment information is stored during the manual driving. In the flowchart of  FIG. 14  described later, the screen  420  of  FIG. 10  shows processing contents of Step S 106 . 
       FIG. 10  illustrates an example in which a warning  431  for reducing the vehicle speed is displayed on the screen  420  displayed on the display device  411 . The warning  431  is displayed across the two windows  421  and  422 . 
       FIG. 11  is a diagram illustrating a display example of the screen  420  for stopping of the surrounding environment information in a case where a period during which the speed of the vehicle  1  exceeds the vehicle-speed threshold value exceeds a predetermined time when the surrounding environment information is stored during manual driving. In the flowchart of  FIG. 14  described later, the screen  420  of  FIG. 11  shows processing contents of Step S 108 . 
       FIG. 11  illustrates an example in which a notification  432  to stop storing of the surrounding environment information is displayed on the screen  420  displayed on the display device  411 . The notification  432  is displayed across the two windows  421  and  422 . 
       FIG. 12  is a diagram illustrating a display example of a screen  440  for performing autonomous driving by using the stored surrounding environment information. In the flowchart of  FIG. 15  described later, the screen  440  of  FIG. 12  shows processing contents of Step S 207 . 
     In  FIG. 12 , the screen  440  for the autonomous driving, which is displayed on the display device  411 , includes a window  451  and a window  452 . On the window  451 , an image of the front of the vehicle  1 , which is picked up by the image pickup sensor  17 A, and the target route  112  are displayed. On the window  452 , an image of the vehicle  1  viewed from above, which is obtained by combining objects detected from the images picked up by the image pickup sensors  17 A to  17 D and the target route  112 , is displayed. 
       FIG. 13  is a graph illustrating a relation between a vehicle speed, a remaining distance, and a time point at the points (m 1  to m 3 ) where the speed of the vehicle  1  is changed in  FIG. 8  described above. Here, the remaining distance indicates the remaining travel distance from a start position to a target position. 
     In  FIG. 13 , a vehicle-speed threshold value v 1  is an upper limit value of the vehicle speed allowing recognition accuracy of the surrounding environment information and estimation accuracy of the host vehicle position to be secured. A vehicle-speed threshold value v 2  in  FIG. 13  indicates a value that reduces the vehicle speed of the vehicle  1  from the vehicle-speed threshold value v 1  as the vehicle approaches a landmark (predetermined object or white line) in the surrounding environment information. A vehicle-speed threshold value v 3  in  FIG. 13  indicates a lower limit value of the vehicle speed of the vehicle  1 , which is hardly influenced by a crack or unevenness of the road surface. The relation between the vehicle-speed threshold value and the vehicle speed lower limit value is v 1 &gt;v 2 &gt;v 3 . 
     When the vehicle speed is reduced, the rate of the pulse detected by the wheel speed sensor  35  is also reduced, and the accuracy of the trajectory (position of the vehicle) of the traveling route calculated based on the pulse is reduced. 
     Therefore, when the surrounding environment information is detected, the vehicle speed lower limit value v 3  is set in advance as a range in which the accuracy of the vehicle speed is not reduced. 
     A point m 1  indicates a storing start point. A point m 2  indicates a point where the host vehicle speed reduces as the vehicle approaches a predetermined landmark in the surrounding environment information. A point m 3  indicates a point where the host vehicle speed reduces as the vehicle approaches a target position. 
     A time point t 1  indicates a time point at which the vehicle passes through a point close to the landmark. A time point t 2  indicates a time point at which the vehicle passes through a point close to the target position. A time point t 3  indicates a time point at which the vehicle has reached the target position. 
     From  FIG. 13 , the vehicle-speed threshold value v 1  of the vehicle  1  is increased to the upper limit value from the vicinity of the point m 1  as the storing start point to the point m 2  where the landmark is recognized. When the vehicle approaches the point m 2  near the landmark, the vehicle speed is reduced to the vehicle-speed threshold value v 2  at which the recognition accuracy of the sensor is improved. At the point m 3  close to the vicinity of the target position, the limit of the vehicle speed lower limit value v 3  is released, and automatic parking is performed. The vehicle speed is limited not to fall below the vehicle speed lower limit value v 3  up to the point m 3 . 
     As described above, the vehicle control device  50  gradually reduces the vehicle-speed threshold value as approaching the target position, so as to reliably recognize the surrounding environment information, secure the estimation accuracy of the position of the vehicle  1 , and secure the control accuracy during autonomous driving. 
       FIG. 14  is a flowchart illustrating processing executed by the vehicle control device  50  when the user performs manual driving and causes the vehicle control device  50  to store surrounding environment information. 
     In Step S 101 , the vehicle control device  50  acquires an estimated value of the current position of the vehicle  1  from the host vehicle position estimation unit  51 , and determines the position of the vehicle  1 . Here, by determining the position of the vehicle  1 , a point where storing of the surrounding environment information in the surrounding environment storage unit  52  is started is specified. In this step, as a method of specifying the position of the vehicle  1 , a method of specifying the approximate position of the vehicle  1  by using GPS information of the position detector  36  may be used. 
     In Step S 102 , the vehicle control device  50  determines whether or not an operation to start storing of the surrounding environment information has been detected by the user. Regarding a determination method, such determination can be performed by detecting whether or not the vehicle control device  50  has operated the predetermined input switch unit  34 . When the operation to start storing of the surrounding environment information is detected, the processing proceeds to Step S 103 . When the operation to start storing of the surrounding environment information is not detected, the processing is ended. 
     In Step S 103 , the vehicle-speed threshold determination unit  53  in the vehicle control device  50  calculates a vehicle-speed threshold value allowing improvement of the recognition accuracy of the surrounding environment. In the present embodiment, the vehicle-speed threshold value is set to a predetermined value set in advance. Here, the vehicle-speed threshold value indicates a threshold value of a vehicle speed at which an accuracy error of dead reckoning for calculating a movement distance and a yaw angle by using a wheel pulse of the wheel speed sensor  35  is reduced when the image pickup sensor  17 , the short distance measuring sensor  24 , the middle distance measuring sensor  22 , and the long distance measuring sensor  23  recognize surrounding environment information such as an object, a white line, and a sign in the surrounding environment of the vehicle  1 . 
     The vehicle-speed threshold value is gradually reduced in accordance with the distance from the current position to the target position as in the vehicle-speed threshold values v 1  and v 2  illustrated in  FIG. 13 . 
     In Step S 104 , the user manually drives the vehicle  1  to start traveling from the storing start position of the surrounding environment information to the target position. During traveling by manual driving, the surrounding environment storage unit  52  recognizes an object, a white line, a sign, or the like in the surrounding environment information of the vehicle  1  by the image pickup sensor  17 , the short distance measuring sensor  24 , the middle distance measuring sensor  22 , and the long distance measuring sensor  23 . The surrounding environment storage unit  52  acquires the position of the vehicle  1  from the host vehicle position estimation unit  51 . 
     In this step, as a method of specifying the position of the vehicle  1  by the host vehicle position estimation unit  51 , a method of estimating the position of the vehicle  1  with higher accuracy than the GPS, by utilizing dead reckoning of calculating the movement distance and the yaw angle using the wheel pulse of the wheel speed sensor  35  can be used. 
     The surrounding environment storage unit  52  stores the surrounding environment information transformed into the predetermined coordinate system by the external-recognition-information conversion unit  56  and data obtained by transforming the positional relation of the vehicle  1  into the predetermined coordinate system, based on the recognition result of the surrounding environment information and the position (traveling route) of the vehicle  1  from the host vehicle position estimation unit  51 . 
     The surrounding environment storage unit  52  stores the position of the vehicle  1  in the memory  3  as the target route  112  used during autonomous driving. 
     In Step S 105 , the vehicle-speed threshold determination unit  53  determines whether or not the vehicle driven by the user is traveling at a value higher than the vehicle-speed threshold value. When the speed of the vehicle  1  is equal to or smaller than the vehicle-speed threshold value, the processing proceeds to Step S 109 . On the other hand, when the speed of the vehicle  1  is higher than the vehicle-speed threshold value, the processing proceeds to Step S 106 . 
     In Step S 106 , the vehicle-speed threshold determination unit  53  notifies the user to reduce the speed of the vehicle  1  to be equal to or smaller than the vehicle-speed threshold value. As a notification method, for example, the user is notified by displaying a message (or warning) for reducing the speed of the vehicle  1  on a liquid crystal display (display device  411 ) or the like. 
     In Step S 107 , the vehicle-speed threshold determination unit  53  determines whether or not the speed of the vehicle  1  driven by the user is traveling at the value higher than the vehicle-speed threshold value for a predetermined time. Here, the predetermined time indicates a time set in advance. When the speed of the vehicle  1  exceeds the vehicle-speed threshold value and the predetermined time has elapsed, the vehicle-speed threshold determination unit  53  causes the processing to proceed to Step S 108 . On the other hand, when the speed of the vehicle  1  is reduced to be equal to or smaller than the vehicle-speed threshold value within a predetermined time, the processing returns to Step S 104  to repeat the above processing. 
     In Step S 108 , when the speed of the vehicle  1  exceeds the vehicle-speed threshold value for the predetermined time, storing of the surrounding environment information is stopped. As a known method of stopping a storing operation for the user, for example, a notification is performed by displaying the stop of storing of the surrounding environment information and the like on a liquid crystal display (display device  411 ) or the like. 
     In Step S 109  in which the vehicle speed is equal to or smaller than the vehicle-speed threshold value, the surrounding environment storage unit  52  determines whether or not an operation to end storing of the surrounding environment information has been detected by an operation of the user. Regarding a determination method, the determination can be performed by detecting that the predetermined input switch unit  34  is operated, the shift range is operated to park, the parking brake is operated, or the like. When the operation to end storing of the surrounding environment information is detected, the processing proceeds to Step S 110 . In a case where the operation to end storing of the surrounding environment information is not detected, the processing returns to Step S 104  to repeat the above processing. 
     In Step S 110 , the surrounding environment storage unit  52  executes processing of storing the surrounding environment information and the host vehicle position information recognized in Step S 104 . As the contents of the storing processing, for example, the external-recognition-information conversion unit  56  converts the relation between the recognized surrounding environment information and the host vehicle position into X-Y coordinates with a storing operation start point as an origin. The converted information is stored in the surrounding environment storage unit  52 , and a message or the like storing the surrounding environment information is displayed on the liquid crystal display (display device  411 ) or the like. The coordinate system of the relation between the recognized surrounding environment information and the host vehicle position may have the target position as the origin. 
       FIG. 15  is a flowchart illustrating processing executed by the vehicle control device  50  when autonomous driving is performed by using the stored surrounding environment information. 
     In Step S 201 , the host vehicle position estimation unit  51  in the vehicle control device  50  determines the position of the vehicle  1 . This is to determine whether or not the vehicle  1  has approached a start point of the surrounding environment information stored in the surrounding environment storage unit  52  by determining the position of the vehicle  1 . In this step, as a method of specifying the position of the vehicle  1 , a method of specifying the approximate position of the vehicle  1  by using GPS information of the position detector  36  may be used. 
     In Step S 202 , the host vehicle position estimation unit  51  determines whether or not the vehicle  1  has approached the storing start point. Regarding the determination method, this determination can be performed by detecting whether the position information of the vehicle  1  coincides with point information at which storing of the surrounding environment information is started. 
     In the present embodiment, the host vehicle position estimation unit  51  can specify the position of the vehicle  1  by utilizing GPS information of the position detector  36 . 
     When the position information of the vehicle  1  coincides with the point information at which the storing of the surrounding environment information is started, the host vehicle position estimation unit  51  causes the processing to proceed to Step S 203 . When the position information of the vehicle  1  does not coincide with the point information at which the storing of the surrounding environment information is started, the processing is ended. 
     In Step S 203 , the stored-information collation unit  54  in the vehicle control device  50  executes collation processing between the current position of the vehicle  1  and the host vehicle position information of the surrounding environment information stored in the surrounding environment storage unit  52 . 
     In the collation processing, whether the host vehicle position information calculated by the host vehicle position estimation unit  51  and the positions of an object and a white line recognized by the image pickup sensor  17 , the short distance measuring sensor  24 , the middle distance measuring sensor  22 , and the long distance measuring sensor  23  coincide with the host vehicle position information in the stored surrounding environment information and the positions of an object and a white line recognized by the image pickup sensor  17 , the short distance measuring sensor  24 , the middle distance measuring sensor  22 , and the long distance measuring sensor  23  by a predetermined amount is compared. 
     Here, the reason of being fixed to be the predetermined amount is that, when the position of the vehicle  1  is GPS information, the accuracy of the host vehicle position information may be decreased. When the host vehicle position estimation unit  51  uses dead reckoning, it is possible to specify the position of the vehicle  1  being traveling with higher accuracy, by collating the detected object, the position information of the white line, and the stored surrounding environment information with each other. 
     In Step S 204 , the stored-information collation unit  54  determines whether or not the collation between the position of the vehicle  1  and the host vehicle position information in the stored surrounding environment information has been completed. As a determination method, this determination can be performed by detecting whether the host vehicle position information calculated by the host vehicle position estimation unit  51  and the positions of an object and a white line recognized by the image pickup sensor  17 , the short distance measuring sensor  24 , the middle distance measuring sensor  22 , and the long distance measuring sensor  23  coincide with the host vehicle position information in the stored surrounding environment information and the positions of an object and a white line recognized by the image pickup sensor  17 , the short distance measuring sensor  24 , the middle distance measuring sensor  22 , and the long distance measuring sensor  23 . 
     When the collation between the position of the vehicle  1  and the host vehicle position information in the stored surrounding environment information is completed, the vehicle  1  is transitioned to a state where the vehicle  1  can be autonomously driven. When the collation between the position of the vehicle  1  and the host vehicle position information in the stored surrounding environment information has been completed, the processing proceeds to Step S 205 . When the collation between the position of the vehicle  1  and the host vehicle position information in the stored surrounding environment information is not completed, the processing returns to Step S 203  to repeat the above processing. 
     In Step S 205 , the vehicle-speed calculation unit  55  calculates a target vehicle speed for autonomous traveling with tracking the stored target route  112 . In the present embodiment, the target vehicle speed is changed in accordance with the distance to the target position from a travel distance from the storing start point to the target position based on the stored traveling route information. 
     As illustrated in  FIG. 13 , the vehicle-speed calculation unit  55  calculates the target vehicle speed so as to be equal to or smaller than the vehicle-speed threshold values v 1  and v 2  corresponding to the distance to the target position. In  FIG. 13 , from the storing start position (point m 1 ) in the surrounding environment storage unit  52  to the point m 2  in the vicinity of a predetermined landmark of the surrounding environment information, the vehicle-speed calculation unit  55  calculates the target vehicle speed so as to be equal to or smaller than the vehicle-speed threshold value v 1 . 
     When the vehicle passes through the point m 2 , the vehicle-speed calculation unit  55  switches to the vehicle-speed threshold value v 2  to reduce the target vehicle speed, improve the recognition accuracy of the surrounding environment information, and travel to the point m 3  near the target position. 
     The vehicle-speed calculation unit  55  sets the target vehicle speed so as not to fall below the vehicle speed lower limit value v 3  up to the point m 3  where parking is started, and secures the accuracy of dead reckoning based on the output of the wheel speed sensor  35 . 
     The vehicle-speed calculation unit  55  releases the limit of the vehicle speed lower limit value v 3  in order to perform parking from the point m 3 , further reduces the target vehicle speed, and performs highly accurate automatic parking toward the target position. 
     In Step S 206 , the vehicle control unit  57  in the vehicle control device  50  determines whether or not an instruction for autonomous driving has been detected by the user. Regarding a determination method, such determination can be performed by detecting whether or not the predetermined input switch unit  34  has been operated. When the instruction for the autonomous driving has been detected, the processing proceeds to Step S 207 . When the instruction for the autonomous driving is not detected, the processing is ended. 
     In Step S 207 , the vehicle control unit  57  performs driving control of the vehicle  1  along the target route  112  stored from the surrounding environment information. 
     In Step S 208 , the vehicle control unit  57  determines whether or not the vehicle  1  has reached the target position. In the determination method, this determination can be performed when the estimated position of the host vehicle calculated by dead reckoning reaches the target position obtained from the surrounding environment information. When the vehicle  1  has reached the target position, the processing proceeds to Step S 209 . When the vehicle  1  has not reached the target position, the processing returns to Step S 207  to repeat the above processing. 
     In Step S 209 , the vehicle control unit  57  ends the control of the vehicle  1 . At the end of the control, a message and the like indicating that the vehicle  1  has reached the target position, and thus the vehicle control is ended is displayed on the liquid crystal display (display device  411 ) or the like. 
     According to the embodiment of the present invention described above, when the surrounding environment is stored by manual driving, it is possible to reduce the accuracy error by operating the vehicle speed at which the accuracy of the vehicle sensor and the host vehicle position estimation is improved. In addition, when the traveling route and the surrounding environment information stored in the autonomous driving are collated with the current position of the vehicle  1  and the surrounding environment information, it is possible to reduce the accuracy error by controlling the vehicle speed so that the accuracy of the vehicle sensor and the host vehicle position estimation is improved. 
     Although the preferred embodiment of the present invention have been described, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention. 
     In addition, in the calculation of the vehicle speed threshold for improving the recognition accuracy illustrated in Step S 103 , the vehicle-speed threshold value (upper limit value) may be set in advance according to the type of road by using high-accuracy map information, and the vehicle-speed threshold value (or target vehicle speed) may be changed in accordance with the road on which the vehicle travels. For example, the vehicle-speed threshold value is changed in the main road and the community road as the type of road. 
     In addition, in the calculation of the vehicle-speed threshold value for improving the recognition accuracy illustrated in Step S 103 , when a speed sign or a road surface sign is recognized by using the image pickup sensor  17  such as a camera, the vehicle-speed threshold value (or the target vehicle speed) may be set to be equal to or smaller than the speed limit recognized from the sign. 
     In addition, the calculation of the vehicle-speed threshold value for improving the recognition accuracy illustrated in Step S 103  may use a distance measuring sensor such as a radar or a sonar. When the distance measuring sensor recognizes an object, the vehicle-speed threshold value may be set to a variable value obtained by calculating the vehicle-speed threshold value from a relation between the position of the vehicle  1  and the position of the object. For example, the vehicle-speed threshold value is changed between a case where the distance between the vehicle  1  and the object is long and a case where the distance is short. 
     In addition, in the calculation of the vehicle-speed threshold value for improving the recognition accuracy shown in Step S 103 , the target position may be set in advance using GPS information of a car navigation device or the like, and the vehicle-speed threshold value may be set to a variable value after depending on traveling route information guided from the position of the vehicle  1  to the target position. For example, the vehicle-speed threshold value is changed in a travel distance, a straight section, and a curved section. 
     In addition, in the notification method for lowering the host vehicle speed to be equal to or smaller than the vehicle-speed threshold value set in the vehicle control device  50  shown in Step S 106 , when the host vehicle speed exceeds the vehicle speed threshold using a sound output device such as a speaker in the vehicle, a sound for lowering the vehicle speed may be output to notify the user. 
     Further, in the notification method for lowering the host vehicle speed to be equal to or smaller than the vehicle-speed threshold value determined by the system shown in Step S 106 , when the host vehicle speed exceeds the vehicle speed threshold using the vibration of the vibrator of the seat installed in the driver seat  413 , the vibrator of the driver seat  413  may be vibrated for a certain period of time for notification. 
     In addition, the calculation of the target vehicle speed at the time of following the stored traveling route shown in Step S 205  may be a variable value in which the target vehicle speed is provided in advance according to the type of road using the high-precision map information. For example, as the type of road, the target vehicle speed is changed between a main road and a community road. 
     In addition, the calculation of the target vehicle speed at the time of tracking the stored traveling route illustrated in Step S 205  may use a distance measuring sensor such as a radar or a sonar. When the distance measuring sensor recognizes an object, the target vehicle speed may be set to a variable value obtained by calculating the vehicle-speed threshold value from a relation between the position of the vehicle  1  and the position of the object. For example, the target vehicle speed is changed between a case where the measured distance between the vehicle  1  and the object is long and a case where the measured distance is short. 
     The calculation of the target vehicle speed at the time of tracking the stored traveling route illustrated in Step S 205  may be set to a variable value for calculating the target vehicle speed from a combination of the storing start position, the target position, a straight section, and a curved section, from the stored traveling route information. For example, the target vehicle speed is changed in a straight section near the storing start point, a curved section, a straight section near the target position, and a curved section. 
     In addition, the surrounding environment storage unit  52  can store the surrounding environment information acquired when the vehicle travels by manual driving with the image pickup sensor  17 , the short distance measuring sensor  24 , the middle distance measuring sensor  22 , and the long distance measuring sensor  23 , and the position information (traveling route) of the vehicle  1  output by the host vehicle position estimation unit  51  at this time. However, there is a possibility that information to be stored becomes enormous depending on the traveling route. Thus, the storage capacity of the vehicle control device  50  may be insufficient. 
     Therefore, as illustrated in  FIG. 16 , an example will be described in which, when the surrounding environment information of the vehicle  1  is used, the user who has executed the storing processing is specified, and the information is accumulated outside the vehicle control device  50  or acquired from the outside of the vehicle control device  50 .  FIG. 16  illustrates the surrounding environment information when information of the user who has executed the storing processing is input to an external data center  701 . 
     The surrounding environment information stored in the surrounding environment storage unit  52  can be accumulated in the external data center by transmitting data to an external facility (data center  701 ) capable of storing a large amount of data by a communication device (and a radio base station  700 ). At this time, a method of specifying the user having stored the surrounding environment information is used. 
     In addition, when there is no surrounding environment information acquired when the vehicle has traveled by manual driving, the surrounding environment storage unit  52  can use a communication device to acquire the surrounding environment information from the external data center  701 , a road infrastructure, or the like that manages the surrounding environment information and the host vehicle position information acquired when another vehicle has traveled in the past. By sharing the surrounding environment information with the external data center  701 , the road infrastructure, and the like, not only the vehicle  1  but also other vehicles having different vehicle types can autonomously travel by using the surrounding environment information. 
     As described above, in the vehicle control device  50  in the present embodiment, the traveling route and the surrounding environment information are stored from a desired position (start position) to the target parking position (target position). Then, the vehicle  1  is moved from the start position to the parking position by autonomous driving. 
     When the vehicle control device  50  starts traveling by manual driving from a position (start position) desired by the user and stores surrounding environment information (an obstacle or a landmark) and a traveling route by each sensor, if the vehicle speed exceeds a predetermined threshold value, the vehicle control device  50  issues a notification for warning and causes the vehicle to travel at a vehicle speed which is equal to or smaller than a predetermined threshold value. 
     The vehicle control device  50  causes the user to travel the vehicle  1  at an appropriate vehicle speed which is equal to or smaller than a predetermined threshold value, thereby making it possible to improve the accuracy of detecting a traveling route by dead reckoning and the detection accuracy of the surrounding environment information (objects) of each sensor. It is possible to improve the accuracy of the autonomous driving by the highly accurate surrounding environment information and traveling route. 
     In the above embodiment, the example has been described in which one user causes the vehicle control device  50  to detect the traveling route and the surrounding environment information by manual driving, and then performs autonomous driving with the detected traveling route and surrounding environment information to move to the target position, but the present invention is not limited thereto. For example, each of a plurality of users may perform manual driving to cause the vehicle control device  50  to detect a traveling route and surrounding environment information. Then, when the vehicle moves to a target position by autonomous driving, data to be used in the autonomous driving may be selected from the plurality of users. 
     Further, in the above embodiment, the example in which the autonomous driving is performed by the vehicle control device  50  has been described, but the present invention is not limited thereto, and may be applied to the vehicle control device  50  that performs automatic parking and steering assistance. 
     CONCLUSION 
     As described above, the vehicle control device  50  in the above embodiment can have the following configuration. 
     (1) A vehicle control device ( 50 ) includes a processor ( 2 ) and a memory ( 3 ) and controls traveling of a vehicle ( 1 ). The vehicle control device ( 50 ) includes a sensor (image pickup sensor  17 , short distance measuring sensor  24 , middle distance measuring sensor  22 , long distance measuring sensor  23 ) that acquires surrounding environment information of the vehicle ( 1 ), a host vehicle position estimation unit ( 51 ) that estimates a traveling route of the vehicle ( 1 ), a surrounding environment storage unit ( 52 ) that stores the surrounding environment information acquired by the sensor ( 17 ) and the traveling route estimated by the host vehicle position estimation unit ( 51 ) in association with each other, a vehicle-speed threshold determination unit ( 53 ) that sets a vehicle speed threshold value when the surrounding environment storage unit ( 52 ) stores the surrounding environment information and the traveling route in association with each other, and determines whether or not a current vehicle speed exceeds the vehicle-speed threshold value when the surrounding environment storage unit ( 52 ) stores the surrounding environment information and the traveling route, and a warning unit ( 41 ) that performs a notification of an excess of the vehicle speed when the vehicle-speed threshold determination unit ( 53 ) determines that the vehicle speed exceeds the vehicle-speed threshold value. 
     With the above configuration, the vehicle control device  50  notifies the warning device  41  that the vehicle speed exceeds a vehicle-speed threshold value, and thus can cause a user (driver) to reduce the vehicle speed, reliably recognize surrounding environment information, and estimate the position information of the vehicle  1  with high accuracy. 
     (2) The vehicle control device ( 50 ) described in (1) further includes a vehicle control unit ( 57 ) that performs autonomous driving based on the traveling route and the surrounding environment information stored in the surrounding environment storage unit ( 52 ). The vehicle control unit ( 57 ) sets a target vehicle speed which is equal to or smaller than the vehicle-speed threshold value. 
     With the above configuration, the vehicle control unit  57  sets the target vehicle speed to be equal to or smaller than the vehicle-speed threshold value, and thus can secure the recognition accuracy of the surrounding environment information, and estimate the position (traveling route) of the vehicle  1  by the host vehicle position estimation unit  51  with high accuracy. 
     (3) The vehicle control device ( 50 ) described in (1) further includes an input unit (input switch unit  34 ) that receives a start position at which storing of surrounding environment information and traveling route is started. The surrounding environment storage unit ( 52 ) stores the surrounding environment information and the traveling route in association with each other from the start position to a target position set in advance. 
     With the above configuration, the vehicle control device  50  can store the surrounding environment information and the traveling route from the start position set by the user (driver) to the predetermined target position, in association with each other. 
     (4) The vehicle control device ( 50 ) described in (2) further includes an input unit ( 34 ) that receives a start position at which storing of surrounding environment information and traveling route is started. The surrounding environment storage unit ( 52 ) stores the surrounding environment information and the traveling route in association with each other from the start position to a target position set in advance. The vehicle control unit ( 57 ) performs autonomous driving in accordance with the surrounding environment information and the traveling route from the start position to the target position, which are stored in the surrounding environment storage unit, when a command of the autonomous driving is received from the input unit ( 34 ). 
     With the above configuration, the vehicle control device  50  stores the surrounding environment information and the traveling route from the start position set by the user (driver) to the predetermined target position, in association with each other. Then, when receiving a command of autonomous driving from the input switch unit  34 , the vehicle control device  50  can perform the autonomous driving in accordance with the traveling route from the start position to the target position and the surrounding environment information stored by the surrounding environment information unit ( 52 ). 
     (5) In the vehicle control device ( 50 ) described in (1), the surrounding environment storage unit ( 52 ) stops storing of the surrounding environment information and the traveling route when the vehicle has traveled at a vehicle speed exceeding the vehicle-speed threshold value for a predetermined time or longer. 
     With the above configuration, when the user (driver) neglects the notification from the warning device  41  and continues driving for a predetermined time or longer at a vehicle speed exceeding the vehicle-speed threshold value, the user pays attention to the storage in the surrounding environment storage unit  52 . Thus, when the vehicle speed is high, the accuracy of the position information due to the deflection of the tire  16  and the detection accuracy of the image pickup sensor  17  and each distance measuring sensor are reduced. Therefore, the surrounding environment storage unit  52  can suppress generation of the surrounding environment information and the traveling route with low accuracy by discarding the information of a region of exceeding the vehicle-speed threshold value. 
     (6) In the vehicle control device ( 50 ) described in (1) or (2), the host vehicle position estimation unit ( 51 ) detects the number of revolutions of a wheel of the vehicle and estimates a position of the vehicle from the number of revolutions. 
     With the above configuration, the host vehicle position estimation unit  51  can generate a highly accurate traveling route by estimating the position of the vehicle  1  by dead reckoning or the like from the output from the wheel speed sensor  35 . 
     (7) In the vehicle control device ( 50 ) described in (1) or (2), the vehicle-speed threshold determination unit ( 53 ) sets the vehicle-speed threshold value as an upper limit value of a vehicle speed allowing accuracy of estimating the position of the vehicle to be secured. 
     With the above configuration, the vehicle control device  50  can generate a highly accurate traveling route while preventing a reduction in accuracy of position information due to deflection of the tire  16  or the like. 
     (8) In the vehicle control device ( 50 ) described in (7), the vehicle-speed threshold value is set to be equal to or greater than a lower limit value (v 3 ) of a vehicle speed allowing accuracy of estimating a position of the vehicle to be secured. 
     With the above configuration, when the vehicle speed is reduced, the rate of the pulse detected by the wheel speed sensor  35  is also reduced. However, by traveling at a vehicle speed which is equal to or smaller than the lower limit value (v 3 ), it is possible to prevent reduction in the accuracy of a trajectory of the traveling route calculated based on the pulse. 
     (9) In the vehicle control device ( 50 ) described in (2), the vehicle control unit ( 57 ) refers to road map information to acquire a speed limit from road type information during traveling, and set a target vehicle speed to be equal to or smaller than the speed limit. 
     With the above configuration, the vehicle control device  50  can set the target vehicle speed in accordance with a travel environment. 
     (10) In the vehicle control device ( 50 ) described in (2), when the surrounding environment information includes a sign indicating a speed limit, the vehicle control unit ( 57 ) sets the target vehicle speed to be equal to or smaller than a value of the sign. 
     With the above configuration, the vehicle control device  50  can set the target vehicle speed in accordance with a travel environment. 
     (11) In the vehicle control device ( 50 ) described in (2), the vehicle control unit ( 57 ) changes the target vehicle speed in accordance with a relation between a position of the vehicle ( 1 ) estimated by the host vehicle position estimation unit ( 51 ) and a target position set in advance. 
     With the above configuration, the vehicle control device  50  can change the target vehicle speed in accordance with the distance to the target position and perform the autonomous driving toward the target position while securing the recognition accuracy. 
     (12) In the vehicle control device ( 50 ) described in (2), the host vehicle position estimation unit ( 51 ) estimates a position of the vehicle by using information of a satellite positioning system, and changes a target vehicle speed in accordance with a distance to a target position set in advance. 
     With the above configuration, the vehicle control device  50  can change the target vehicle speed in accordance with the distance from the position of the vehicle  1  to the target position based on GPS information, and perform the autonomous driving toward the target position while securing the recognition accuracy. 
     (13) In the vehicle control device ( 50 ) described in (1), the surrounding environment storage unit ( 52 ) stores the surrounding environment information and the traveling route in an external device ( 701 ). 
     With the above configuration, even when the amount of data of the surrounding environment information and the traveling route increases, it is possible to reliably store the surrounding environment information and the traveling route in the external data center  701 . 
     (14) In the vehicle control device ( 50 ) described in (2), the surrounding environment storage unit ( 52 ) stores the surrounding environment information and the traveling route in an external device ( 701 ), and the vehicle control unit ( 57 ) acquires the traveling route and the surrounding environment information stored in the external device ( 701 ), and performs the autonomous driving. 
     With the above configuration, even when the amount of data of the surrounding environment information and the traveling route increases, it is possible to perform the autonomous driving by acquiring the surrounding environment information and the traveling route from the external data center  701 . 
     Note that, the present invention is not limited to the above example, and various modifications may be provided. For example, the above embodiments are described in detail in order to explain the present invention in an easy-to-understand manner, and the above embodiments are not necessarily limited to a case including all the described configurations. Further, some components in one embodiment can be replaced with the components in another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, for some of the components in the embodiments, any of addition, deletion, or replacement of other components can be applied singly or in combination. 
     Some or all of the configurations, functions, functional units, processing means, and the like may be realized in hardware by being designed with an integrated circuit, for example. Further, the above-described respective components, functions, and the like may be realized by software by the processor interpreting and executing a program for realizing the respective functions. Information such as a program, a table, and a file, that realizes each function can be stored in a memory, a recording device such as a hard disk and a solid state drive (SSD), or a recording medium such as an IC card, an SD card, and a DVD. 
     Control lines and information lines considered necessary for the descriptions are illustrated, and not all the control lines and the information lines in the product are necessarily shown. In practice, it may be considered that almost all components are connected to each other. 
     REFERENCE SIGNS LIST 
     
         
           1  vehicle 
           2  processor 
           3  memory 
           11  engine 
           12  automatic transmission 
           13  propeller shaft 
           14  differential gear 
           15  drive shaft 
           16  wheel 
           17  image pickup sensor 
           19  various sensors 
           20  brake device 
           21  electric power steering 
           22  middle distance measuring sensor 
           23  long distance measuring sensor 
           24  short distance measuring sensor 
           34  input switch unit 
           35  wheel sensor 
           36  position detector 
           37  communication device 
           40  various-sensor/actuator ECU 
           41  warning unit 
           50  vehicle control device 
           51  host vehicle position estimation unit 
           52  surrounding environment storage unit 
           53  vehicle-speed threshold determination unit 
           54  stored-information collation unit 
           55  vehicle-speed calculation unit 
           56  external-recognition-information conversion unit 
           57  vehicle control unit 
           24 A to  24 L short distance measuring sensor 
           17 A to  17 D image pickup sensor 
           22 A to  22 D middle distance measuring sensor 
           23  long distance measuring sensor