Patent Publication Number: US-2022214691-A1

Title: Energy consumption estimation device and energy consumption estimation method

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to Japanese Patent Application No. 2021-000227 filed on Jan. 4, 2021, incorporated herein by reference in its entirety. 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a technique for estimating energy consumption of a vehicle on a travel route. 
     2. Description of Related Art 
     WO 2019/106745 discloses a demand-responsive transport (DRT) system that controls vehicles that are part of a DRT service in response to a request from a user. The DRT system receives a passenger&#39;s travel request including a desired departure time, a desired arrival time, a departure point, and a destination, and creates a dispatch plan of DRT vehicles based on the travel requests collected by the specified time. 
     SUMMARY 
     In a case where a travel route is derived from the departure point and the destination requested by the passenger, such a travel route may be derived in consideration of a distance of the travel route such that the vehicle does not detour. The travel route derived based on the distance may not be energy efficient because the energy consumption when running on such a travel route is not known. 
     The present disclosure provides a technique capable of accurately estimating energy consumption when running on a travel route. 
     An energy consumption estimation device according to one aspect of the present disclosure is an energy consumption estimation device which includes a reception unit configured to receive, from a user, request information including a departure point and a destination, a route derivation unit configured to derive a plurality of travel routes based on the departure point and the destination included in the request information, an acquisition unit configured to acquire section energy consumption in a case where a vehicle travels on a road section, which is derived based on information on vehicle speed and information on road undulations, and an estimation unit configured to respectively estimate energy consumption of the vehicle in a case where the vehicle travels on the derived travel routes by adding energy consumption for road sections included in the travel route. 
     Another aspect of the present disclosure is an energy consumption estimation method. The method includes a step of receiving, from a user, request information including a departure point and a destination, a step of deriving a plurality of travel routes based on the departure point and the destination included in the request information, a step of acquiring section energy consumption in a case where a vehicle travels on a road section, which is derived based on information on vehicle speed and information on road undulations, and a step of estimating energy consumption of the vehicle respectively in a case where the vehicle travels on the derived travel routes by adding energy consumption for road sections included in the travel route. 
     With the present disclosure, it is possible to provide a technique capable of accurately estimating energy consumption when running on a travel route. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Features, advantages, and technical and industrial significance of exemplary embodiments of the disclosure will be described below with reference to the accompanying drawings, in which like signs denote like elements, and wherein: 
         FIG. 1  is a diagram illustrating an outline of a service planning system according to an embodiment; 
         FIG. 2A  is a diagram illustrating a request for a vehicle service by a user, and a view showing an image displayed when the vehicle service is requested by a user terminal device; 
         FIG. 2B  is another diagram illustrating a request for the vehicle service by the user, and a view showing an image displayed when the vehicle service is requested by the user terminal device; 
         FIG. 3  is a diagram illustrating a functional configuration of the service planning system according to the embodiment; 
         FIG. 4A  is a diagram illustrating request information transmitted from the user terminal device; 
         FIG. 4B  is a diagram illustrating vehicle information transmitted from a vehicle management device; 
         FIG. 4C  is a diagram illustrating road information transmitted from an information provision device; 
         FIG. 5  is a diagram illustrating an energy consumption estimation method, and also a diagram illustrating a first travel route and a second travel route derived by a route derivation unit; and 
         FIG. 6  is a flowchart of a process in which a service planning device of the embodiment creates a service plan. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       FIG. 1  shows an outline of a service planning system  1  according to an embodiment. The service planning system  1  includes a service planning device  10 , a user terminal device  12 , a vehicle management device  14 , a vehicle  16 , and an information provision device  18 . The service planning system  1  receives a reservation for a DRT service from a user, and dispatches the vehicle  16  in response to the request to transport the user and the user&#39;s luggage. Users can share the same vehicle  16  shown in  FIG. 1 . In  FIG. 1 , a bus is depicted as the vehicle  16 , but the present disclosure is not limited thereto. A small vehicle, for example, may be adopted. 
     The user terminal device  12  can communicate with the service planning device  10 . The user terminal device  12  is provided with a display unit  12   a  that displays an image. The display unit  12   a  may be a touch-operable touchscreen. The user requests the service planning device  10  to dispatch the vehicle  16  using the user terminal device  12 . The user terminal device  12  may be a mobile terminal device held by each user, and has an application program for requesting the service offered by the vehicle  16 . The user terminal device  12  executes the application program and transmits request information to the service planning device  10 . 
     The user&#39;s request information is accepted by a predetermined deadline, for example, the day before the service date, or a predetermined time before the service time. The service planning device  10  creates a service plan corresponding to the established request and transmits the plan to the vehicle management device  14 . 
     The vehicle management device  14  manages services offered by the vehicle  16 . The vehicle management device  14  can communicate with the service planning device  10  and an in-vehicle device of the vehicle  16 , receives vehicle information including location information of the vehicle  16  from the vehicle  16 , and transmits such information to the service planning device  10  together with vehicle information stored in advance. Further, the vehicle management device  14  receives the service plan from the service planning device  10  and controls the vehicle  16  such that the vehicle travels according to the service plan. The vehicle  16  may be capable of autonomous driving. The vehicle  16  is equipped with a rechargeable battery  16   a  as a travel energy source. A plurality of rechargeable batteries  16   a  may be mounted on the vehicle  16 . 
     The information provision device  18  provides the road information to the service planning device  10 . The road information includes information on road undulations. The road information may include traffic information for the corresponding road. 
     In addition, in a case where the vehicle  16  can run on each of several travel routes, it is possible to identify an energy-efficient travel route by identifying the amount of energy consumed by the service in advance. Therefore, the service planning device  10  of the embodiment functions as an energy consumption estimation device by estimating the energy consumption when the vehicle runs on each of several travel routes. Further, the service planning device  10  can accurately estimate the energy consumption based on the information on vehicle speed and the information on road undulations. 
       FIGS. 2A and 2B  are diagrams respectively illustrating the request for a service by the user, and views respectively showing an image displayed when the request is made for a vehicle service offered by the vehicle  16  using the user terminal device  12 .  FIG. 2A  shows a screen displayed by the user terminal device  12  when transmitting the request, and  FIG. 2B  shows a screen displayed by the user terminal device  12  when selecting a service route according to the request. 
     As shown in  FIG. 2A , the user inputs reservation date and time, departure point, and destination into the user terminal device  12 , and causes the user terminal device  12  to transmit the request information to the service planning device  10 . Upon receiving the request information, the service planning device  10  derives several service routes from the departure point to the destination, and proposes those service routes to the user. Further, the service planning device  10  calculates energy consumption, distance, time required, and charges when traveling on each of the several service routes, and transmits same to the user terminal device  12 . 
     As shown in  FIG. 2B , the user terminal device  12  displays several service routes according to the request information, and allows the user to select a route that they wish to travel on. The user terminal device  12  displays the energy consumption of each service route, the distance of each service route, the travel time, and the charges. The energy consumption, time, and charges are estimated values. 
     In the service planning system  1  of the embodiment, the charges are set based on the energy consumption, and the user can choose a service route with lower energy consumption that may take a longer time. In addition, the vehicle  16  can travel on the service route with lower energy consumption. 
       FIG. 3  shows a functional configuration of the service planning system  1 . In  FIG. 3 , each component that is a functional block for performing various processes can be configured by a circuit block, a memory, and other LSIs in terms of hardware, or, configured by a program loaded into the memory in terms of software. Therefore, it will be apparent to those skilled in the art that those functional blocks can be implemented in various forms by hardware only, software only, or a combination thereof, but not limited to any one of them. 
     The service planning device  10  includes a communication unit  20 , a reception unit  22 , a route derivation unit  24 , a vehicle dispatch unit  26 , a section consumption calculation unit  27 , an estimation unit  28 , an acquisition unit  30 , a service determination unit  32 , and a proposal unit  34 . The communication unit  20  can communicate with the user terminal device  12 , the vehicle management device  14 , and the information provision device  18 , in order to transmit and receive information. 
     The acquisition unit  30  acquires the vehicle information from the vehicle management device  14  and the road information from the information provision device  18 . The acquisition unit  30  may acquire each piece of information at a predetermined cycle, or may acquire each piece of information when the service plan is created. Further, the estimation unit  28  receives the request information from the user terminal device  12  via the communication unit  20 . These pieces of information will be described with reference to the new drawings. 
       FIG. 4A  is a diagram illustrating the request information transmitted from the user terminal device  12 .  FIG. 4B  is a diagram illustrating the vehicle information transmitted from the vehicle management device  14 .  FIG. 4C  is a diagram illustrating the road information transmitted from an information provision device  18 . 
     The request information includes a user ID, departure point information, destination information, and information on a desired date and time. The departure point information and the destination information may be location information of a preset bus stop, or may be location information indicated by latitude or longitude. That is, the vehicle  16  for DRT may move between preset stops, or may move to a location desired by the user. The information on the desired date and time may specify at least one of departure time, departure time zone, arrival time, and arrival time zone. The request information may include the number of passengers and a single request may be made for a plurality of passengers. 
     The vehicle information shown in  FIG. 4B  includes vehicle ID, location information, vehicle weight, and service schedule information. The vehicle ID, which is identification information of each vehicle, is associated with the location information, the vehicle weight, and the service schedule information. 
     The location information of the vehicle is transmitted from the in-vehicle device of the vehicle  16  to the vehicle management device  14 . The vehicle weight is used to calculate the energy consumption during the travel. The service schedule information is information on a service schedule of the vehicle  16  that has already been determined by, for example, the service planning device  10 . The service schedule information may include the user ID which is used when the reservation is made. The vehicle information may further include vehicle type information, passenger capacity, regeneration performance information, and the like. 
     The road information shown in  FIG. 4C  includes road link ID, distance, information on road undulations, and information on vehicle speed. The road link ID indicates a location of a road section, and the distance indicates a distance of the section corresponding to the road link ID. The road section may be set from a branch point to another branch point, where the road branches off. The information on road undulations may be slope information of the road section corresponding to the road link ID, or altitude information of the section. The slope information may be a road slope oriented from one end to the other end of the section. The altitude information may be a height of any location in the section, or a height difference between one end and the other end of the section. That is, the altitude information may be the height of the section or the height difference between adjacent sections. 
     The information on vehicle speed may be, for example, an average vehicle speed obtained by collecting and averaging vehicle speeds of vehicles that have traveled on the section corresponding to the road link ID. The average vehicle speed may be calculated based on the location information and the vehicle speed transmitted to the information provision device  18  by the vehicle traveling in the section corresponding to the road link ID, or based on the vehicle speed measured by a sensor provided on the road. The average vehicle speed may be transmitted by an information provision device different from the device sending the information on road undulations. 
     Returning to  FIG. 3 , the reception unit  22  receives the request information including the departure point and the destination from the user. The route derivation unit  24  derives a travel route based on the request information. The travel route derived by the route derivation unit  24  may be referred to as a service route. Start and end points of the travel route match the departure point and the destination of the request information, respectively. 
     The route derivation unit  24  derives several travel routes based on the request information and the road information, including a travel route for running on a major road, a travel route for shortening the distance, and a travel route for running on a road with less undulations. The route derivation unit  24  derives several travel routes for different purposes, for example, to identify a shorter distance, a road with less undulations, or a route that has been frequently traveled on. Several travel routes derived from the same request information have the same start point and end point, but they follow different paths. 
     The route derivation unit  24  may derive a travel route based on travel histories of various vehicles, and may derive a travel route based on a program using a neural network. Moreover, sometimes the route derivation unit  24  can derive only one travel route within an area having a low road density. The route derivation unit  24  may derive a travel route based on several pieces of the request information, and may derive a travel route passing through the departure points and the destinations included in the pieces of the request information. 
     The vehicle dispatch unit  26  appropriately assigns the vehicle  16  in response to the request, based on the travel route derived by the route derivation unit  24 , the desired date and time indicated by the request information, and the vehicle information acquired by the acquisition unit  30 . The vehicle dispatch unit  26  may have a dispatch program for assigning the vehicle  16 , and the vehicle information and the travel route may be input to the dispatch program to assign the vehicle  16 . 
     The estimation unit  28  estimates the energy consumption of the vehicle  16  when traveling on each of several travel routes derived by the route derivation unit  24 . The estimation unit  28  estimates the energy consumption based on the derived travel route, the road information of the travel route, and the vehicle information of the assigned vehicle  16 . This estimation method will be described with reference to the new drawing. 
       FIG. 5  is a diagram illustrating an energy consumption estimation method, and also a diagram illustrating a first travel route  40  and a second travel route  42  derived by the route derivation unit  24 . The first travel route  40  and the second travel route  42  are divided into road sections corresponding to the road link IDs. For example, the first travel route  40  is divided from the starting point, such as a road section  44   a,  a road section  44   b,  and a road section  44   c,  in this order. 
     The road information includes the information on road undulations and the average vehicle speed for each road section, and the section consumption calculation unit  27  uses a calculation model shown in the following Equation (1) to derive section energy consumption E of each road section. Equation (1) is a calculation model used for traveling uphill. 
         E=C   1 ( Mva+MgΔh+τMgv )+ C   2   ρC   D   Av   3 /2   (1)
 
     C 1  and C 2  represent vehicle coefficients, M represents vehicle weight, v represents average vehicle speed, a represents acceleration, Δh represents height difference, τ represents a rolling resistance coefficient, ρ represents air density, C D  represents an air resistance coefficient, and A represents a front area of the vehicle. Since energy is regenerated for traveling downhill, the amount of regenerated energy is subtracted from the calculated result of Equation (1). 
     The section consumption calculation unit  27  calculates the section energy consumption E based on the average vehicle speed of the vehicle that has traveled on the road section and the information on road undulations of the road section. The section consumption calculation unit  27  may calculate the section energy consumption E of the road section based on vehicle speed preset as the information on vehicle speed and the information on road undulations. The preset vehicle speed may be, for example, a legal speed limit. The legal speed limit may be set for each road section. In other words, the section consumption calculation unit  27  calculates the section energy consumption E by using either the preset vehicle speed or the average vehicle speed based on the actual past history as information on vehicle speed. The section energy consumption E calculated by the section consumption calculation unit  27  is stored in a memory of the service planning device  10 . 
     The acquisition unit  30  acquires the section energy consumption from the memory of the service planning device  10 . The estimation unit  28  estimates the energy consumption when traveling on the travel route derived by the route derivation unit  24  by adding up the energy consumption for each road section included in the travel route. The estimation unit  28  estimates the energy consumption of the vehicle  16  for each of several travel routes derived by the route derivation unit  24 . 
     By estimating the energy consumption for each travel route, it is possible to select a travel route with lower energy consumption, and thus the energy consumption can be reduced. Additionally, by calculating the section energy consumption for each of road sections into which the travel route is divided using the information on road undulations and the average vehicle speed, the estimation unit  28  can accurately calculate the energy consumption that reflects the road undulations and the vehicle speed for the road in detail. 
     The section energy consumption E calculated by the section consumption calculation unit  27  may be calculated in real time based on the information on vehicle speed shown in current road traffic information, but may be calculated in advance at a legal speed limit. In other words, the section energy consumption E may be stored in advance in the memory of the service planning device  10  or stored separately for uphill and downhill in the same road section while a plurality of the section energy consumptions may be stored according to the vehicle types. 
     Returning to  FIG. 3 , the estimation unit  28  estimates the estimated charges based on the estimated energy consumption. The estimated charges may be the total value of the amount proportional to the energy consumption and the basic fare. However, the charges are merely estimated values and do not determine the actual charges. Furthermore, the estimation unit  28  estimates service time based on the average vehicle speed for each road section. The vehicle often travels on a route including major roads, which may not be the shortest distance and may have large undulations, in other words, the travel route is not the most energy-efficient route. The optimum travel route can be estimated by calculating the energy consumptions, service times, and estimated charges of several travel routes in advance. 
     The proposal unit  34  generates proposal information that proposes, to the user, several travel routes derived based on the request information, and transmits the proposal information to the user terminal device  12  via the communication unit  20 . Consequently, the proposal unit  34  can propose to the user several travel routes from which they can choose one. The proposal information that proposes a travel route to the user may include energy consumption, estimated charges, and estimated service time for each travel route. Therefore, the user can determine a travel route to travel by comparing charges and times. 
     The proposal unit  34  may propose to the user only one travel route having a higher priority from among several travel routes derived by the route derivation unit  24 . The proposal unit  34  derives scores of several travel routes and proposes the three routes with the highest scores to the user. The proposal unit  34  derives the score based on the energy consumption and the expected service time of the travel route, and derives the score such that the score gets higher as the energy consumption is lower and the service time is shorter. Therefore, it is possible to propose the optimum travel route for the user. Further, the proposal unit  34  may select and propose at least the travel route with the lowest energy consumption from among the derived travel routes. Consequently, it is possible to guide the user to select the travel route with the lowest energy consumption. 
     The travel routes proposed by the proposal unit are displayed to the user through the user terminal device  12  as shown in  FIG. 2B . When the user operates the user terminal device  12  and selects one of the travel routes, the selection result is transmitted from the user terminal device  12  to the service planning device  10 . The acquisition unit  30  acquires the user&#39;s selection result, the service determination unit  32  determines that the vehicle will run on the travel route shown in the selection result, and creates a service plan in which the vehicle  16  and the travel route are defined. The created service plan is transmitted to the vehicle management device  14 . Moreover, in a case where a plurality of users is traveling in the vehicle, the user who made the earliest request may be entitled to decide the travel route. 
       FIG. 6  is a flowchart of a process in which the service planning device  10  of the embodiment creates a service plan. The reception unit  22  of the service planning device  10  receives the request information from the user terminal device  12  by a predetermined deadline (S 10 ). The route derivation unit  24  derives travel routes based on the request information (S 12 ). The vehicle dispatch unit  26  assigns the vehicle  16  according to the request information. 
     The acquisition unit  30  acquires the road information from the information provision device  18  (S 14 ) and also acquires the vehicle information from the vehicle management device  14  (S 16 ). The road information includes the average vehicle speed and the information on road undulations for each road section. The section consumption calculation unit  27  calculates the section energy consumption of the road section based on the average vehicle speed and the information on road undulations, and the estimation unit  28  adds up the section energy consumption for each road section and for each travel route to estimate the energy consumption (S 18 ). 
     The proposal unit  34  transmits the travel route candidates together with their energy consumptions to the user terminal device  12  (S 20 ). The acquisition unit  30  acquires a selection result indicating which travel route the user has selected from the user terminal device  12  (S 22 ). The service determination unit  32  determines the vehicle  16  and the travel route corresponding to the request based on the selection result of the user so as to fulfill the request (S 24 ), and creates the service plan (S 26 ). 
     It will be apparent to those skilled in the art that the embodiments are merely examples, various modifications can be made to combinations of the components, and such modifications also fall within the scope of the present disclosure. 
     For example, the present embodiment shows one aspect of creating a DRT service plan, but the embodiment is not limited to this aspect. For example, the user may personally drive a vehicle. In such a case, the service planning device  10  may receive the request information defining the departure point and the destination, and propose a travel route with lower energy consumption.