Patent Application
20210245778
This nonprovisional application is based on Japanese Patent Application No. 2020-015720 filed with the Japan Patent Office on Jan. 31, 2020, the entire contents of which are hereby incorporated by reference.
The present disclosure relates to control of a vehicle that is carrying out autonomous driving.
An autonomous driving system that has a vehicle travel without requiring an operation by a user has recently been developed. For example, for being mounted on an existing vehicle, the autonomous driving system may be provided separately from the vehicle with an interface being interposed.
For such an autonomous driving system, for example, Japanese Patent Laying-Open No. 2018-132015 discloses a technique allowing addition of an autonomous driving function without greatly modifying an existing vehicle platform, by providing an electronic control unit (ECU) that manages motive power of a vehicle and an ECU for autonomous driving independently of each other.
During autonomous driving, deterioration over time or misalignment of a vehicle may cause deviation between an estimated value of a steering angle based on information obtained from the vehicle platform and an actually requested steering angle. Therefore, elimination of deviation of the steering angle is required in order to appropriately control the vehicle.
An object of the present disclosure is to provide a vehicle on which an autonomous driving system is mountable, the vehicle achieving improved accuracy in steering during autonomous driving.
A vehicle according to one aspect of the present disclosure is a vehicle on which an autonomous driving system is mountable. The vehicle includes a vehicle platform that carries out vehicle control in accordance with a command from the autonomous driving system and a vehicle control interface that interfaces between the autonomous driving system and the vehicle platform. The vehicle platform receives a tire turning angle command that requests for a wheel steer angle transmitted from the autonomous driving system. The vehicle platform transmits a signal indicating an estimated wheel angle which is an estimated value of the wheel steer angle to the autonomous driving system. The vehicle platform steers the vehicle in accordance with the tire turning angle command set based on a wheel estimation angle while the vehicle is in a straight-ahead travel state.
Since the vehicle is thus steered in accordance with the tire turning angle command set based on the wheel estimation angle while the vehicle is in the straight-ahead travel state, deviation of the steering angle can be eliminated and accuracy in steering during autonomous driving can be improved.
Furthermore, in one embodiment, the tire turning angle command is set based on a relative value relative to the estimated wheel angle.
Deviation of the steering angle can thus be eliminated and accuracy in steering during autonomous driving can be improved.
Furthermore, in one embodiment, the estimated wheel angle while the vehicle is in the straight-ahead travel state is set as a correction value for a value representing the tire turning angle command and the correction value is updated while an autonomous mode is not set.
Since the estimated wheel angle while the vehicle is in the straight-ahead travel state is thus set as the correction value for the tire turning angle command, accuracy in steering can be improved. Furthermore, the correction value is updated while the autonomous mode is not set. Therefore, for example, great change in behavior of the vehicle during autonomous driving in case of great change in correction value can be suppressed.
A vehicle according to another aspect of the present disclosure includes an autonomous driving system and a vehicle platform that carries out vehicle control in accordance with a command from the autonomous driving system. A command that requests for a wheel steer angle is transmitted from the autonomous driving system to the vehicle platform. A signal indicating an estimated value of the wheel steer angle is transmitted from the vehicle platform to the autonomous driving system. The autonomous driving system requests for the wheel steer angle based on an estimated value of the wheel steer angle while the vehicle is in a straight-ahead travel state.
The foregoing and other objects, features, aspects and advantages of the present disclosure will become more apparent from the following detailed description of the present disclosure when taken in conjunction with the accompanying drawings.
An embodiment of the present disclosure will be described below in detail with reference to the drawings. The same or corresponding elements in the drawings have the same reference characters allotted and description thereof will not be repeated.
Vehicle 10 includes a vehicle main body 100 and an autonomous driving kit (which is denoted as “ADK” below) 200. Vehicle main body 100 includes a vehicle control interface 110, a vehicle platform (which is denoted as “VP” below) 120, and a data communication module (DCM) 190.
Vehicle 10 can carry out autonomous driving in accordance with commands from ADK 200 attached to vehicle main body 100. Though
Vehicle control interface 110 can communicate with ADK 200 over a controller area network (CAN). Vehicle control interface 110 receives various commands from ADK 200 or outputs a state of vehicle main body 100 to ADK 200 by executing a prescribed application program interface (API) defined for each communicated signal.
When vehicle control interface 110 receives a command from ADK 200, it outputs a control command corresponding to the received command to VP 120. Vehicle control interface 110 obtains various types of information on vehicle main body 100 from VP 120 and outputs the state of vehicle main body 100 to ADK 200. A configuration of vehicle control interface 110 will be described in detail later.
VP 120 includes various systems and various sensors for controlling vehicle main body 100. VP 120 carries out various types of vehicle control in accordance with a command given from ADK 200 through vehicle control interface 110. Namely, as VP 120 carries out various types of vehicle control in accordance with a command from ADK 200, autonomous driving of vehicle 10 is carried out. A configuration of VP 120 will also be described in detail later.
ADK 200 includes an autonomous driving system (which is denoted as “ADS” below) 202 for autonomous driving of vehicle 10. ADS 202 creates, for example, a driving plan of vehicle 10 and outputs various commands for traveling vehicle 10 in accordance with the created driving plan to vehicle control interface 110 in accordance with the API defined for each command. ADS 202 receives various signals indicating states of vehicle main body 100 from vehicle control interface 110 in accordance with the API defined for each signal and has the received vehicle state reflected on creation of the driving plan. A configuration of ADS 202 will also be described later.
DCM 190 includes a communication interface (I/F) for vehicle main body 100 to wirelessly communicate with data server 500. DCM 190 outputs various types of vehicle information such as a speed, a position, or an autonomous driving state to data server 500. DCM 190 receives from autonomous driving related mobility services 700 through MSPF 600 and data server 500, various types of data for management of travel of an autonomous driving vehicle including vehicle 10 by mobility services 700. MSPF 600 is an integrated platform to which various mobility services are connected. In addition to autonomous driving related mobility services 700, not-shown various mobility services (for example, various mobility services provided by a ride-share company, a car-sharing company, an insurance company, a rent-a-car company, and a taxi company) are connected to MSPF 600. Various mobility services including mobility services 700 can use various functions provided by MSPF 600 by using APIs published on MSPF 600, depending on service contents.
Autonomous driving related mobility services 700 provide mobility services using an autonomous driving vehicle including vehicle 10. Mobility services 700 can obtain, for example, operation control data of vehicle 10 that communicates with data server 500 or information stored in data server 500 from MSPF 600, by using the APIs published on MSPF 600. Mobility services 700 transmit, for example, data for managing an autonomous driving vehicle including vehicle 10 to MSPF 600, by using the API.
MSPF 600 publishes APIs for using various types of data on vehicle states and vehicle control necessary for development of the ADS, and an ADS provider can use as the APIs, the data on the vehicle states and vehicle control necessary for development of the ADS stored in data server 500.
During autonomous driving of the vehicle, compute assembly 210 obtains an environment around the vehicle and a pose, a behavior, and a position of the vehicle from various sensors which will be described later as well as a state of the vehicle from VP 120 which will be described later through vehicle control interface 110 and sets a next operation (acceleration, deceleration, or turning) of the vehicle. Compute assembly 210 outputs various instructions for realizing a set next operation of vehicle 10 to vehicle control interface 110.
HMI 230 presents information to a user and accepts an operation during autonomous driving, during driving requiring an operation by a user, or at the time of transition between autonomous driving and driving requiring an operation by the user. HMI 230 is implemented, for example, by a touch panel display, a display apparatus, and an operation apparatus.
Sensors for perception 260 include sensors that perceive an environment around the vehicle, and are implemented, for example, by at least any of laser imaging detection and ranging (LIDAR), a millimeter-wave radar, and a camera.
The LIDAR refers to a distance measurement apparatus that measures a distance based on a time period from emission of pulsed laser beams (infrared rays) until return of the laser beams reflected by an object. The millimeter-wave radar is a distance measurement apparatus that measures a distance or a direction to an object by emitting radio waves short in wavelength to the object and detecting radio waves that return from the object. The camera is arranged, for example, on a rear side of a room mirror in a compartment and used for shooting an image of the front of the vehicle. Information obtained by sensors for perception 260 is output to compute assembly 210. As a result of image processing by artificial intelligence (AI) or an image processing processor onto images or video images shot by the camera, another vehicle, an obstacle, or a human in front of the vehicle can be recognized.
Sensors for pose 270 include sensors that detect a pose, a behavior, or a position of the vehicle, and are implemented, for example, by an inertial measurement unit ° MU) or a global positioning system (GPS).
The MU detects, for example, an acceleration in a front-rear direction, a lateral direction, and a vertical direction of the vehicle and an angular speed in a roll direction, a pitch direction, and a yaw direction of the vehicle. The GPS detects a position of vehicle 10 based on information received from a plurality of GPS satellites that orbit the Earth. Information obtained by sensors for pose 270 is output to compute assembly 210.
Sensor cleaning 290 removes soiling attached to various sensors during travel of the vehicle. Sensor cleaning 290 removes soiling on a lens of the camera or a portion from which laser beams or radio waves are emitted, for example, with a cleaning solution or a wiper.
Vehicle control interface 110 includes a vehicle control interface box (VCIB) 111 and a VCIB 112. VCIBs 111 and 112 each contain a central processing unit (CPU) and a memory (including, for example, a read only memory (ROM) and a random access memory (RAM)) neither of which is shown. Though VCIB 111 is equivalent in function to VCIB 112, it is partially different in a plurality of systems connected thereto that make up VP 120.
VCIBs 111 and 112 are each communicatively connected to compute assembly 210 of ADS 202. VCIB 111 and VCIB 112 are communicatively connected to each other.
Each of VCIBs 111 and 112 relays various instructions from ADS 202 and provides them as control commands to VP 120. More specifically, each of VCIBs 111 and 112 uses various command instructions provided from ADS 202 to generate control commands to be used for control of each system of VP 120 by using information such as a program (for example, an API) stored in a memory and provides the control commands to a destination system. Each of VCIBs 111 and 112 relays vehicle information output from VP 120 and provides the vehicle information as a vehicle state to ADS 202. The information indicating the vehicle state may be identical to the vehicle information, or information to be used for processing performed in ADS 202 may be extracted from the vehicle information.
As VCIB 111 and VCIB 112 equivalent in function relating to an operation of at least one of (for example, braking or steering) systems are provided, control systems between ADS 202 and VP 120 are redundant. Thus, when some kind of failure occurs in a part of the system, the function (turning or stopping) of VP 120 can be maintained by switching between the control systems as appropriate or disconnecting a control system where failure has occurred.
VP 120 includes brake systems 121A and 121B, steering systems 122A and 122B, an electric parking brake (EPB) system 123A, a P-Lock system 123B, a propulsion system 124, a pre-crash safety (PCS) system 125, and a body system 126.
VCIB 111 is communicatively connected to brake system 121B, steering system 122A, EPB system 123A, P-Lock system 123B, propulsion system 124, and body system 126 of the plurality of systems of VP 120, through a communication bus.
VCIB 112 is communicatively connected to brake system 121A, steering system 122B, and P-Lock 123B of the plurality of systems of VP 120, through a communication bus.
Brake systems 121A and 121B can control a plurality of braking apparatuses provided in wheels of the vehicle. Brake system 121A may be equivalent in function to brake system 121B, or any one of them may be able to independently control braking force of each wheel during travel of the vehicle and the other thereof may be able to control braking force such that equal braking force is generated in the wheels during travel of the vehicle. The braking apparatus includes, for example, a disc brake system that is operated with a hydraulic pressure regulated by an actuator.
A wheel speed sensor 127 is connected to brake system 121B. Wheel speed sensor 127 is provided, for example, in each wheel of the vehicle and detects a rotation speed of each wheel. Wheel speed sensor 127 outputs the detected rotation speed of each wheel to brake system 121B. Brake system 121B outputs the rotation speed of each wheel to VCIB 111 as one of pieces of information included in vehicle information.
Each of brake systems 121A and 121B generates a braking instruction to a braking apparatus in accordance with a prescribed control command provided from ADS 202 through vehicle control interface 110. For example, brake systems 121A and 121B control the braking apparatus based on a braking instruction generated in any one of the brake systems, and when a failure occurs in any one of the brake systems, the braking apparatus is controlled based on a braking instruction generated in the other brake system.
Steering systems 122A and 122B can control a steering angle of a steering wheel of vehicle 10 with a steering apparatus. Steering system 122A is similar in function to steering system 122B. The steering apparatus includes, for example, rack-and-pinion electric power steering (EPS) that allows adjustment of a steering angle by an actuator.
A pinion angle sensor 128A is connected to steering system 122A. A pinion angle sensor 128B provided separately from pinion angle sensor 128A is connected to steering system 122B. Each of pinion angle sensors 128A and 128B detects an angle of rotation (a pinion angle) of a pinion gear coupled to a rotation shaft of the actuator that implements the steering apparatus. Pinion angle sensors 128A and 128B output detected pinion angles to steering systems 122A and 122B, respectively.
Each of steering systems 122A and 122B generates a steering instruction to the steering apparatus in accordance with a prescribed control command provided from ADS 202 through vehicle control interface 110. For example, steering systems 122A and 122B control the steering apparatus based on the steering instruction generated in any one of the steering systems, and when a failure occurs in any one of the steering systems, the steering apparatus is controlled based on a steering instruction generated in the other steering system.
EPB system 123A can control the EPB provided in at least any of a plurality of wheels provided in vehicle 10. The EPB is provided separately from the braking apparatus, and fixes a wheel by an operation of an actuator. The EPB, for example, activates a drum brake for a parking brake provided in at least one of the plurality of wheels provided in vehicle 10 to fix the wheel with an actuator, or activates a braking apparatus to fix a wheel with an actuator capable of regulating a hydraulic pressure to be supplied to the braking apparatus separately from brake systems 121A and 121B.
EPB system 123A controls the EPB in accordance with a prescribed control command provided from ADS 202 through vehicle control interface 110.
P-Lock system 123B can control a P-Lock apparatus provided in a transmission of vehicle 10. The P-Lock apparatus fits a protrusion provided at a tip end of a parking lock pawl, a position of which is adjusted by an actuator, into a tooth of a gear (locking gear) provided as being coupled to a rotational element in the transmission. Rotation of an output shaft of the transmission is thus fixed and the wheels are fixed.
P-Lock system 123B controls the P-Lock apparatus in accordance with a prescribed control command provided from ADS 202 through vehicle control interface 110. P-Lock system 123B activates the P-Lock apparatus, for example, when a control command provided from ADS 202 through vehicle control interface 110 includes a control command to set a shift range to a parking range (which is denoted as a P range below), and deactivates the P-Lock apparatus when the control command includes a control command to set the shift range to a range other than the P range.
Propulsion system 124 can switch a shift range with the use of a shift apparatus and can control driving force of vehicle 10 in a direction of movement of vehicle 10 that is generated from a drive source. The shift apparatus can select any of a plurality of shift ranges. The plurality of shift ranges include, for example, the P range, a neutral range, a forward travel range, and a rearward travel range. The drive source includes, for example, a motor generator and an engine.
Propulsion system 124 controls the shift apparatus and the drive source in accordance with a prescribed control command provided from ADS 202 through vehicle control interface 110. Propulsion system 124 controls the shift apparatus to set the shift range to the P range, for example, when a control command provided from ADS 202 through vehicle control interface 110 includes the control command for setting the shift range to the P range.
PCS system 125 controls the vehicle to avoid collision or to mitigate damage by using a camera/radar 129. PCS system 125 is communicatively connected to brake system 121B. PCS system 125 detects an obstacle (an obstacle or a human) in front by using, for example, camera/radar 129, and when it determines that there is possibility of collision based on a distance to the obstacle, it outputs a braking instruction to brake system 121B so as to increase braking force.
Body system 126 can control, for example, components such as a direction indicator, a horn, or a wiper, depending on a state or an environment of travel of vehicle 10. Body system 126 controls the above-described components in accordance with a prescribed control command provided from ADS 202 through vehicle control interface 110.
An operation apparatus that can manually be operated by a user for the braking apparatus, the steering apparatus, the EPB, the P-Lock apparatus, the shift apparatus, and the drive source described above may separately be provided.
Various commands provided from ADS 202 to vehicle control interface 110 include a propulsion direction command that requests for switching of the shift range, an immobilization command that requests for activation or deactivation of the EPB or the P-Lock apparatus, an acceleration command that requests for acceleration or deceleration of vehicle 10, a tire turning angle command that requests for a tire turning angle of the steering wheel, and an automating command that requests for switching of an autonomous state between an autonomous mode and a manual mode.
For example, when the autonomous mode is selected as the autonomous state by an operation by a user onto HMI 230 in vehicle 10 configured as above, autonomous driving is carried out. As described above, ADS 202 initially creates a driving plan during autonomous driving. The driving plan includes a plurality of plans relating to operations by vehicle 10 such as a plan to continue straight-ahead travel, a plan to turn left or right at a prescribed intersection on the way on a predetermined travel path, or a plan to change a driving lane to a lane different from the lane on which the vehicle is currently traveling.
ADS 202 extracts a physical control quantity (for example, an acceleration or a deceleration or a tire turning angle) necessary for vehicle 10 to operate in accordance with the created driving plan. ADS 202 splits the physical quantity for each API execution cycle. ADS 202 executes the API based on the split physical quantity and provides various commands to vehicle control interface 110. ADS 202 obtains a vehicle state from VP 120 and creates again a driving plan on which the obtained vehicle state is reflected. ADS 202 thus allows autonomous driving of vehicle 10.
During autonomous driving, deterioration over time (for example, uneven wear of a tire) or misalignment of vehicle 10 may cause deviation between an estimated wheel angle which is an estimated value of a steering angle based on information (for example, a pinion angle) obtained from VP 120 and a steering angle actually requested in a tire turning angle command. Therefore, elimination of deviation of the steering angle for improving accuracy in steering is required in order to appropriately control the vehicle.
In the present embodiment, VP 120 steers the vehicle in accordance with a tire turning angle command set based on a wheel estimation angle while vehicle 10 is in the straight-ahead travel state.
Since the vehicle is thus steered in accordance with the tire turning angle command set based on the wheel estimation angle while vehicle 10 is in the straight-ahead travel state, deviation of the steering angle can be eliminated and accuracy in steering during autonomous driving can be improved.
Processing performed by ADS 202 (more specifically, compute assembly 210) in the present embodiment will be described below with reference to
In a step (the step being denoted as S below) 11, ADS 202 determines whether or not vehicle 10 is in the straight-ahead travel state. For example, when a white line indicating a driving lane on which vehicle 10 travels exhibits a straight line equal to or longer than a prescribed length or when a record of movement of vehicle 10 based on the GPS shows a straight line equal to or longer than a prescribed length, ADS 202 may determine vehicle 10 as being in the straight-ahead travel state. When vehicle 10 is determined as being in the straight-ahead travel state (YES in S11), the process makes transition to S12.
In S12, ADS 202 obtains an estimated wheel angle. ADS 202 obtains the estimated wheel angle based on the vehicle state provided from VP 120 through vehicle control interface 110. VP 120 obtains a pinion angle based on a result of detection by pinion angle sensor 128A or 128B and calculates the estimated wheel angle based on the obtained pinion angle. VP 120 calculates the estimated wheel angle each time a predetermined period elapses and provides the calculated estimated wheel angle as one of pieces of information included in the vehicle state to ADS 202 through vehicle control interface 110.
In S13, ADS 202 calculates a relative value. ADS 202 calculates as a relative value, a difference between a value of the estimated wheel angle while vehicle 10 is in the straight-ahead travel state and a reference value of the tire turning angle while the vehicle is in the straight-ahead travel state. The reference value of the tire turning angle while the vehicle is in the straight-ahead travel state is a value that represents a state that the vehicle is not steered, and it is, for example, a value indicating zero.
In S14, ADS 202 determines whether or not the autonomous state has been set to the manual mode. ADS 202 determines whether or not the autonomous state has been set to the manual mode, for example, based on a state of a flag that indicates the autonomous mode. The flag indicating the autonomous mode is turned on, for example, when an operation by a user onto HMI 230 for carrying out autonomous driving is accepted, and the flag is turned off when the autonomous mode is canceled by the operation performed by the user or in accordance with a driving condition and switching to the manual mode is made. When ADS 202 determines the autonomous state as having been set to the manual mode based on an off state of the flag indicating the autonomous mode (YES in S14), the process makes transition to S15.
In S15, ADS 202 updates the correction value. Specifically, ADS 202 updates the value stored as the correction value to the relative value calculated in S13.
For example, when switching to the autonomous mode is made next time, ADS 202 sets as the tire turning angle command, a value calculated by adding the correction value to the initial value of the tire turning angle command corresponding to the steering angle set in accordance with the driving plan.
Processing performed in ADS 202 in the autonomous mode will be described with reference to
In S21, ADS 202 determines whether or not the autonomous state has been set to the autonomous mode. For example, when the flag indicating the autonomous mode described above is on, ADS 202 determines the autonomous state as having been set to the autonomous mode. When the autonomous state is determined as having been set to the autonomous mode (YES in S21), the process makes transition to S22.
In S22, ADS 202 sets the initial value of the tire turning angle command. ADS 202 sets the initial value of the tire turning angle command in accordance with the driving plan. For example, when the driving plan indicates straight-ahead travel, ADS 202 sets the initial value of the tire turning angle command to zero.
In S23, ADS 202 corrects the tire turning angle command. ADS 202 corrects the tire turning angle command with the correction value stored in a storage. Specifically, ADS 202 sets as the tire turning angle command, a value calculated by adding the correction value to the initial value of the tire turning angle command.
In S24, ADS 202 transmits the corrected tire turning angle command to vehicle control interface 110.
Processing performed in vehicle control interface 110 (more specifically, VCIB 111 or VCIB 112) will now be described with reference to
In S31, vehicle control interface 110 determines whether or not it has received the tire turning angle command from ADS 202. When the vehicle control interface determines that it has received the tire turning angle command (YES in S31), the process makes transition to S32.
In S32, vehicle control interface 110 controls the steering apparatus. Vehicle control interface 110 controls the steering apparatus in accordance with the received tire turning angle command.
In S33, vehicle control interface 110 obtains the estimated wheel angle. In S34, vehicle control interface 110 transmits the obtained estimated wheel angle to ADS 202 as one of pieces of information of the vehicle state.
Operations by ADS 202 based on the structure and the flowchart as set forth above will be described with reference to
For example, as shown with LN1 in
Since the autonomous mode has been set (YES in S21) at this time, the initial value of the tire turning angle command is set in accordance with the driving plan (S22) and the correction value is added to the set initial value to correct the tire turning angle command (S23). The corrected tire turning angle command is transmitted to vehicle control interface 110 (S24).
When vehicle control interface 110 receives the tire turning angle command (YES in S31), the steering apparatus is controlled (S32). Thereafter, the estimated wheel angle is obtained (S33) and the estimated wheel angle is transmitted to ADS 202 (S34).
As shown in
When the manual mode is set as the autonomous state at time t2 (YES in S14), the correction value is updated to the calculated relative value as shown with LN3 in
Therefore, when the autonomous mode is then set (YES in S21) and the initial value of the tire turning angle command is set in accordance with the driving plan (S22), the updated correction value is added to the set initial value to correct the tire turning angle command (S23), and the corrected tire turning angle command is transmitted to vehicle control interface 110 (S24).
As set forth above, according to vehicle 10 in the present embodiment, the vehicle is steered in accordance with the tire turning angle command set based on the wheel estimation angle while vehicle 10 is in the straight-ahead travel state. Therefore, deviation of the steering angle can be eliminated and accuracy in steering during autonomous driving can be improved. Therefore, a vehicle on which the autonomous driving system can be mounted, the vehicle achieving improved accuracy in steering during autonomous driving, can be provided.
Since the tire turning angle command is set based on a relative value relative to the estimated wheel angle, deviation of the steering angle can be eliminated and accuracy in steering during autonomous driving can be improved when vehicle 10 travels straight or makes a turn.
Since the estimated wheel angle while vehicle 10 is in the straight-ahead travel state is set as the correction value for the tire turning angle command, accuracy in steering can be improved. The correction value is updated while the autonomous mode is not set. Therefore, for example, great change in behavior of the vehicle during autonomous driving in case of great change in correction value can be suppressed.
A modification will be described below.
In the embodiment described above, though VCIB 111 or 112 is described as performing the processing shown in the flowchart in
In the embodiment described above, though vehicle control interface 110 is described as performing the processing shown in the flowchart in
In the embodiment described above, the relative value is described as being calculated each time a predetermined period elapses and the correction value is described as being updated with the calculated relative value while the autonomous state is set to the manual mode. For example, however, when a difference between the relative value and the correction value yet to be updated exceeds a threshold value or when the relative value is different from an immediately preceding correction value, the correction value may be updated with the relative value calculated while the autonomous state is set to the manual mode.
The entirety or a part of the modification above may be carried out as being combined as appropriate.
Toyota's MaaS Vehicle Platform
API Specification
for ADS Developers
[Standard Edition #0.1]
History of Revision
Index
1. Outline 4
2. Structure 5
1. Outline
1.1. Purpose of this Specification
This document is an API specification of Toyota Vehicle Platform and contains the outline, the usage and the caveats of the application interface.
1.2. Target Vehicle
e-Palette, MaaS vehicle based on the POV (Privately Owned Vehicle) manufactured by Toyota
1.3. Definition of Term
1.4. Precaution for Handling
This is an early draft of the document.
All the contents are subject to change. Such changes are notified to the users. Please note that some parts are still T.B.D. will be updated in the future.
2. Structure
2.1. Overall Structure of MaaS The overall structure of MaaS with the target vehicle is shown (
Vehicle control technology is being used as an interface for technology providers.
Technology providers can receive open API such as vehicle state and vehicle control, necessary for development of automated driving systems.
2.2. System Structure of MaaS Vehicle
The system architecture as a premise is shown (
The target vehicle will adopt the physical architecture of using CAN for the bus between ADS and VCIB. In order to realize each API in this document, the CAN frames and the bit assignments are shown in the form of “bit assignment table” as a separate document.
3. Application Interfaces
3.1. Responsibility Sharing of when Using APIs
Basic responsibility sharing between ADS and vehicle VP is as follows when using APIs.
[ADS]
The ADS should create the driving plan, and should indicate vehicle control values to the VP.
[VP]
The Toyota VP should control each system of the VP based on indications from an ADS.
3.2. Typical Usage of APIs
In this section, typical usage of APIs is described.
CAN will be adopted as a communication line between ADS and VP. Therefore, basically, APIs should be executed every defined cycle time of each API by ADS.
A typical workflow of ADS of when executing APIs is as follows (
3.3. APIs for Vehicle Motion Control
In this section, the APIs for vehicle motion control which is controllable in the MaaS vehicle is described.
3.3.1. Functions
3.3.1.1. Standstill, Start Sequence
The transition to the standstill (immobility) mode and the vehicle start sequence are described. This function presupposes the vehicle is in Autonomy_State=Autonomous Mode. The request is rejected in other modes.
The below diagram shows an example.
Acceleration Command requests deceleration and stops the vehicle. Then, when Longitudinal_Velocity is confirmed as 0 [km/h], Standstill Command=“Applied” is sent. After the brake hold control is finished, Standstill Status becomes “Applied”. Until then, Acceleration Command has to continue deceleration request. Either Standstill Command=“Applied” or Acceleration Command's deceleration request were canceled, the transition to the brake hold control will not happen. After that, the vehicle continues to be standstill as far as Standstill Command=“Applied” is being sent. Acceleration Command can be set to 0 (zero) during this period.
If the vehicle needs to start, the brake hold control is cancelled by setting Standstill Command to “Released”. At the same time, acceleration/deceleration is controlled based on Acceleration Command (
EPB is engaged when Standstill Status=“Applied” continues for 3 minutes.
3.3.1.2. Direction Request Sequence
The shift change sequence is described. This function presupposes that Autonomy_State=Autonomous Mode. Otherwise, the request is rejected.
Shift change happens only during Actual_Moving_Direction=“standstill”). Otherwise, the request is rejected.
In the following diagram shows an example. Acceleration Command requests deceleration and makes the vehicle stop. After Actual_Moving_Direction is set to “standstill”, any shift position can be requested by Propulsion Direction Command. (In the example below, “D” “R”).
During shift change, Acceleration Command has to request deceleration.
After the shift change, acceleration/deceleration is controlled based on Acceleration Command value (
3.3.1.3. WheelLock Sequence
The engagement and release of wheel lock is described. This function presupposes Autonomy_State=Autonomous Mode, otherwise the request is rejected.
This function is conductible only during vehicle is stopped. Acceleration Command requests deceleration and makes the vehicle stop. After Actual_Moving_Direction is set to “standstill”, WheelLock is engaged by Immobilization Command=“Applied”. Acceleration Command is set to Deceleration until Immobilization Status is set to “Applied”.
If release is desired, Immobilization Command=“Release” is requested when the vehicle is stationary. Acceleration Command is set to Deceleration at that time.
After this, the vehicle is accelerated/decelerated based on Acceleration Command value (
3.3.1.4. Road_Wheel_Angle_Request
This function presupposes Autonomy_State=“Autonomous Mode”, and the request is rejected otherwise.
Tire Turning Angle Command is the relative value from Estimated_Road_Wheel_Angle_Actual.
For example, in case that Estimated_Road_Wheel_Angle_Actual=0.1 [rad] while the vehicle is going straight;
If ADS requests to go straight ahead, Tire Turning Angle Command should be set to 0+0.1=0.1 [rad].
If ADS requests to steer by −0.3 [rad], Tire Turning Angle Command should be set to −0.3+0.1=−0.2 [rad].
3.3.1.5. Rider Operation
3.3.1.5.1. Acceleration Pedal Operation
While in Autonomous driving mode, accelerator pedal stroke is eliminated from the vehicle acceleration demand selection.
3.3.1.5.2. Brake Pedal Operation
The action when the brake pedal is operated. In the autonomy mode, target vehicle deceleration is the sum of 1) estimated deceleration from the brake pedal stroke and 2) deceleration request from AD system.
3.3.1.5.3. Shift_Lever_Operation
In Autonomous driving mode, driver operation of the shift lever is not reflected in Propulsion Direction Status.
If necessary, ADS confirms Propulsion Direction by Driver and changes shift position by using Propulsion Direction Command.
3.3.1.5.4. Steering Operation
When the driver (rider) operates the steering, the maximum is selected from
1) the torque value estimated from driver operation angle, and
2) the torque value calculated from requested wheel angle.
Note that Tire Turning Angle Command is not accepted if the driver strongly turns the steering wheel. The above-mentioned is determined by Steering_Wheel_Intervention flag.
3.3.2. Inputs
3.3.2.1. Propulsion Direction Command
Request to switch between forward (D range) and back (R range)
Values
Remarks
3.3.2.2. Immobilization Command
Request to engage/release WheelLock
Values
Remarks
3.3.2.3. Standstill Command
Request the vehicle to be stationary
Values
Remarks
3.3.2.4. Acceleration Command
Command vehicle acceleration
Values
Estimated_Max_Decel_Capability to Estimated_Max_Accel_Capability [m/s2]
Remarks
3.3.2.5. Tire Turning Angle Command
Command tire turning angle
Values
Remarks
3.3.2.6. Autonomization Command
Request to transition between manual mode and autonomy mode
Values
3.3.3. Outputs
3.3.3.1. Propulsion Direction Status
Current shift range
Values
Remarks
3.3.3.2. Propulsion Direction by Driver
Shift lever position by driver operation
Values
Remarks
3.3.3.3. Immobilization Status
Output EPB and Shift-P status
Values
<Primary>
<Secondary>
Remarks
3.3.3.4. Immobilization Request by Driver
Driver operation of EPB switch
Values
Remarks
3.3.3.5. Standstill Status
Vehicle stationary status
Values
Remarks
3.3.3.6. Estimated Coasting Rate
Estimated vehicle deceleration when throttle is closed
Values
[unit: m/s2]
Remarks
3.3.3.7. Estimated_Max_Accel_Capability
Estimated maximum acceleration
Values
[unit: m/s2]
Remarks
3.3.3.8. Estimated_Max_Decel_Capability
Estimated maximum deceleration
Values
−9.8 to 0 [unit: m/s2]
Remarks
3.3.3.9. Estimated_Road_Wheel_Angle_Actual
Front wheel steer angle
Values
Remarks
3.3.3.10. Estimated_Road_Wheel_Angle_Rate_Actual
Front wheel steer angle rate
Values
Remarks
3.3.3.11. Steering_Wheel_Angle_Actual
Steering wheel angle
Values
Remarks
3.3.3.12. Steering_Wheel_Angle_Rate_Actual
Steering wheel angle rate
Values
Remarks
3.3.3.13. Current_Road_Wheel_Angle_Rate_Limit
Road wheel angle rate limit
Values
Remarks
Calculated from the “vehicle speed-steering angle rate” chart like below
A) At a very low speed or stopped situation, use fixed value of 0.4 [rad/s]
B) At a higher speed, the steering angle rate is calculated from the vehicle speed using 2.94 m/s3
The threshold speed between A and B is 10 [km/h] (
3.3.3.14. Estimated_Max_Lateral_Acceleration_Capability
Estimated max lateral acceleration
Values
2.94 [unit: m/s2] fixed value
Remarks
3.3.3.15. Estimated_Max_Lateral_Acceleration_Rate_Capability
Estimated max lateral acceleration rate
Values
2.94 [unit: m/s3] fixed value
Remarks
3.3.3.16. Accelerator_Pedal_Position
Position of the accelerator pedal (How much is the pedal depressed?)
Values
0 to 100 [unit: %]
Remarks
3.3.3.17. Accelerator_Pedal_Intervention
This signal shows whether the accelerator pedal is depressed by a driver (intervention).
Values
Remarks
When Accelerator_Pedal_Position is higher than the defined threshold value (ACCL_INTV), this signal [Accelerator_Pedal_Intervention] will turn to “depressed”.
When the requested acceleration from depressed acceleration pedal is higher than the requested acceleration from system (ADS, PCS etc.), this signal will turn to “Beyond autonomy acceleration”.
3.3.3.18. Brake_Pedal_Position
Position of the brake pedal (How much is the pedal depressed?)
Values
0 to 100 [unit: %]
Remarks
3.3.3.19. Brake_Pedal_Intervention
This signal shows whether the brake pedal is depressed by a driver (intervention).
Values
Remarks
Detail design (
3.3.3.20. Steering_Wheel_Intervention
This signal shows whether the steering wheel is turned by a driver (intervention).
Values
Remarks
3.3.3.21. Shift_Lever_Intervention
This signal shows whether the shift lever is controlled by a driver (intervention).
Values
Remarks
3.3.3.22. WheelSpeed_FL, WheelSpeed_FR, WheelSpeed_RL, WheelSpeed_RR
wheel speed value
Values
Remarks
3.3.3.23. WheelSpeed_FL Rotation, WheelSpeed_FR Rotation, WheelSpeed_RL Rotation, WheelSpeed_RR Rotation
Rotation direction of each wheel
Values
Remarks
3.3.3.24. Actual_Moving_Direction
Rotation direction of wheel
Values
Remarks
“Reverse”.
When more than two WheelSpeed_Rotations are “Forward”, this signal shows “Forward”.
3.3.3.25. Longitudinal_Velocity
Estimated longitudinal velocity of vehicle
Values
Remarks
This signal is output as the absolute value.
3.3.3.26. Longitudinal_Acceleration
Estimated longitudinal acceleration of vehicle
Values
Remarks
3.3.3.27. Lateral_Acceleration
Sensor value of lateral acceleration of vehicle
Values
Remarks
3.3.3.28. Yawrate
Sensor value of Yaw rate
Values
Remarks
3.3.3.29. Autonomy_State
State of whether autonomy mode or manual mode
Values
Remarks
3.3.3.30. Autonomy_Ready
Situation of whether the vehicle can transition to autonomy mode or not
Values
Remarks
Please see the summary of conditions.
3.3.3.31. Autonomy_Fault
Status of whether the fault regarding a functionality in autonomy mode occurs or not
Values
Remarks
3.4. APIs for BODY control
3.4.1. Functions
T.B.D.
3.4.2. Inputs
3.4.2.1. Turnsignallight_Mode_Command
Command to control the turnsignallight mode of the vehicle platform
Values
Remarks
T.S.D.
Detailed Design
When Turnsignallight_Mode_Command=1, vehicle platform sends left blinker on request.
When Turnsignallight_Mode_Command=2, vehicle platform sends right blinker on request.
3.4.2.2. Headlight_Mode_Command
Command to control the headlight mode of the vehicle platform
Values
Remarks
3.4.2.3. Hazardlight_Mode_Command
Command to control the hazardlight mode of the vehicle platform
Values
Remarks
3.4.2.4. Horn_Pattern_Command
Command to control the pattern of horn ON-time and OFF-time per cycle of the vehicle platform
Remarks
3.4.2.5. Horn_Number_of_Cycle_Command
Command to control the Number of horn ON/OFF cycle of the vehicle platform
Values
0-7 [−]
Remarks
3.4.2.6. Horn_Continuous_Command
Command to control of horn ON of the vehicle platform
Values
Remarks
3.4.2.7. Windshieldwiper_Mode_Front_Command
Command to control the front windshield wiper of the vehicle platform
Values
Remarks
3.4.2.8. Windshieldwiper_Intermittent_Wiping_Speed_Command
Command to control the Windshield wiper actuation interval at the Intermittent mode
Values
Remarks
3.4.2.9. Windshieldwiper Mode Rear Command
Command to control the rear windshield wiper mode of the vehicle platform
Values
Remarks
3.4.2.10. Hvac_1st_Command
Command to start/stop 1st row air conditioning control
Values
Remarks
Therefore, in order to control 4 (four) hvacs (1st_left/right, 2nd_left/right) individually, VCIB achieves the following procedure after Ready-ON. (This functionality will be implemented from the CV.)
#1: Hvac_1st Command=ON
#2: Hvac_2nd Command=ON
#3: Hvac_TargetTemperature_2nd_Left_Command
#4: Hvac_TargetTemperature_2nd_Right_Command
#5: Hvac_Fan_Level_2nd_Row_Command
#6: Hvac_2nd_Row_AirOutlet_Mode_Command
#7: Hvac_TargetTemperature_1st_Left_Command
#8: Hvac_TargetTemperature_1st_Right_Command
#9: Hvac_Fan_Level_1st_Row_Command
#10: Hvac_1st_Row_AirOutlet_Mode_Command
* The interval between each command needs 200 ms or more.
* Other commands are able to be executed after #1.
3.4.2.11. Hvac_2nd_Command
Command to start/stop 2nd row air conditioning control
Values
Remarks
N/A
3.4.2.12. Hvac_TargetTemperature_1st_Left_Command
Command to set the target temperature around front left area
Values
Remarks
3.4.2.13. Hvac_TargetTemperature_1st_Right_Command
Command to set the target temperature around front right area
Values
Remarks
3.4.2.14. Hvac_TargetTemperature_2nd Left_Command
Command to set the target temperature around rear left area
Values
Remarks
3.4.2.15. Hvac_TargetTemperature_2nd Right_Command
Command to set the target temperature around rear right area
Values
Remarks
3.4.2.16. Hvac_Fan_Level_1st_Row_Command
Command to set the fan level on the front AC
Values
Remarks
3.4.2.17. Hvac_Fan_Level_2nd_Row_Command
Command to set the fan level on the rear AC
Values
Remarks
3.4.2.18. Hvac_1st_Row_AirOutlet_Mode_Command
Command to set the mode of 1st row air outlet
Values
Remarks
3.4.2.19. Hvac_2nd Row_AirOutlet_Mode_CommandCommand to set the mode of 2nd row air outlet
Values
Remarks
3.4.2.20. Hvac_Recirculate_Command
Command to set the air recirculation mode
Values
Remarks
3.4.2.21. Hvac_AC_Command
Command to set the AC mode
Values
Remarks
3.4.3. Outputs
3.4.3.1. Turnsignallight_Mode_Status
Status of the current turnsignallight mode of the vehicle platform
Values
Remarks
3.4.3.2. Headlight_Mode_Status
Status of the current headlight mode of the vehicle platform
Values
Remarks
N/A
Detailed Design
3.4.3.3. Hazardlight_Mode_Status
Status of the current hazard lamp mode of the vehicle platform
Values
Remarks
N/A
3.4.3.4. Horn_Status
Status of the current horn of the vehicle platform
Values
Remarks
3.4.3.5. Windshieldwiper_Mode_Front_Status
Status of the current front windshield wiper mode of the vehicle platform
Values
Remarks
Fail Mode Conditions
3.4.3.6. Windshieldwiper_Mode_Rear_Status
Status of the current rear windshield wiper mode of the vehicle platform
Values
Remarks
3.4.3.7. Hvac_1st_Status
Status of activation of the 1st row HVAC
Values
Remarks
Status of activation of the 2nd row HVAC
Values
Remarks
3.4.3.9. Hvac_Temperature_1st_Left_Status
Status of set temperature of 1st row left
Values
Remarks
3.4.3.10. Hvac_Temperature_1st_Right_Status
Status of set temperature of 1st row right
Values
Remarks
3.4.3.11. Hvac_Temperature_2nd_Left_Status
Status of set temperature of 2nd row left
Values
Remarks
3.4.3.12. Hvac_Temperature_2nd_Right_Status
Status of set temperature of 2nd row right
Values
Remarks
3.4.3.13. Hvac_Fan_Level_1st_Row_Status
Status of set fan level of 1st row
Values
Remarks
3.4.3.14. Hvac_Fan_Level_2nd_Row_Status
Status of set fan level of 2nd row
Values
Remarks
3.4.3.15. Hvac_1st_Row_AirOutlet_Mode_Status
Status of mode of 1st row air outlet
Values
Remarks
3.4.3.16. Hvac_2nd_Row_AirOutlet_Mode_Status
Status of mode of 2nd row air outlet
Values
Remarks
3.4.3.17. Hvac Recirculate Status
Status of set air recirculation mode
Values
Remarks
3.4.3.18. Hvac_AC_Status
Status of set AC mode
Values
Remarks
3.4.3.19. 1st_Right_Seat_Occupancy_Status
Seat occupancy status in 1st left seat
Values
Remarks
When there is luggage on the seat, this signal may be set to “Occupied”.
3.4.3.20. 1st_Left_Seat_Belt_Status
Status of driver's seat belt buckle switch
Values
Remarks
It is checking to a person in charge, when using it. (Outputs “undetermined=10” as an initial value.)
3.4.3.21. 1st Right_Seat_Belt_Status
Status of passenger's seat belt buckle switch
Values
Remarks
It is checking to a person in charge, when using it. (Outputs “undetermined=10” as an initial value.)
3.4.3.22. 2nd_Left_Seat_Belt_Status
Seat belt buckle switch status in 2nd left seat
Values
Remarks
3.4.3.23. 2nd Right_Seat_Belt_Status
Seat belt buckle switch status in 2nd right seat
Values
Remarks
3.5. APIs for Power control
3.5.1. Functions
T.B.D.
3.5.2. Inputs
3.5.2.1. Power Mode Request
Command to control the power mode of the vehicle platform
Values
Remarks
The followings are the explanation of the three power modes, i.e. [Sleep][Wake][Driving Mode], which are controllable via API.
[Sleep]
Vehicle power off condition. In this mode, the high voltage battery does not supply power, and neither VCIB nor other VP ECUs are activated.
[Wake]
VCIB is awake by the low voltage battery. In this mode, ECUs other than VCIB are not awake except for some of the body electrical ECUs.
[Driving Mode]
Ready ON mode. In this mode, the high voltage battery supplies power to the whole VP and all the VP ECUs including VCIB are awake.
3.5.3. Outputs
3.5.3.1. Power_Mode_Status
Status of the current power mode of the vehicle platform
Values
Remarks
3.6. APIs for Safety
3.6.1. Functions
T.B.D.
3.6.2. Inputs
3.6.3. Outputs
3.6.3.1. Request for Operation
Request for operation according to status of vehicle platform toward ADS
Values
Remarks
3.6.3.2. Passive_Safety_Functions_Triggered
Crash detection Signal
Values
Remarks
Priority: crash detection>normal
Transmission interval is 100 ms within fuel cutoff motion delay allowance time (1 s) so that data can be transmitted more than 5 times. In this case, an instantaneous power interruption is taken into account.
3.6.3.3. Brake_System_Degradation_Modes
Indicate Brake System status
Values
Remarks
3.6.3.4. Propulsive_System_Degradation_Modes
Indicate Powertrain_System status
Values
Remarks
3.6.3.5. Direction_Control_Degradation_Modes
Indicate Direction_Control status
Values
Remarks
3.6.3.6. WheelLock_Control_Degradation_Modes
Indicate WheelLock Control status
Values
Remarks
3.6.3.7. Steering_System_Degradation_Modes
Indicate Steering System status
Values
Remarks
3.6.3.8. Power_System_Degradation_Modes
[T.B.D]
3.6.3.9. Communication_Degradation_Modes
[T.B.D]
3.7. APIs for Security
3.7.1. Functions
T.B.D.
3.7.2. Inputs
3.7.2.1. 1st_Left_Door_Lock_Command, 1st Right Door Lock Command, 2nd_Left_Door_Lock_Command, 2nd Right Door Lock Command
Command to control each door lock of the vehicle platform
Values
Remarks
3.7.2.2. Central Vehicle Lock Exterior Command
Command to control the all door lock of the vehicle platform.
Values
Remarks
3.7.3. Outputs
3.7.3.1. 1st_Left_Door_Lock_Status
Status of the current 1st-left door lock mode of the vehicle platform
Values
Remarks
3.7.3.2. 1st_Right_Door_Lock_Status
Status of the current 1st-right door lock mode of the vehicle platform
Values
Remarks
3.7.3.3. 2nd Left_Door_Lock_Status
Status of the current 2nd-left door lock mode of the vehicle platform
Values
Remarks
3.7.3.4. 2nd Right Door Lock Status
Status of the current 2nd-right door lock mode of the vehicle platform
Values
Remarks
3.7.3.5. Central Vehicle Exterior Locked Status
Status of the current all door lock mode of the vehicle platform
Values
Remarks
3.7.3.6. Vehicle Alarm Status Status of the current vehicle alarm of the vehicle platform
Values
Remarks
N/A
3.8. APIs for MaaS Service
3.8.1. Functions
T.B.D.
3.8.2. Inputs
3.8.3. Outputs
Toyota's MaaS Vehicle Platform
Architecture Specification
[Standard Edition #0.1]
History of Revision
Index
1. General Concept
1.1. Purpose of this Specification
This document is an architecture specification of Toyota's MaaS Vehicle Platform and contains the outline of system in vehicle level.
1.2. Target Vehicle Type
This specification is applied to the Toyota vehicles with the electronic platform called 19ePF [ver.1 and ver.2].
The representative vehicle with 19ePF is shown as follows.
e-Palette, Sienna, RAV4, and so on.
1.3. Definition of Term
1.4. Precaution for Handling
This is an early draft of the document.
All the contents are subject to change. Such changes are notified to the users. Please note that some parts are still T.B.D. will be updated in the future.
2. Architectural Concept
2.1. Overall Structure of MaaS
The overall structure of MaaS with the target vehicle is shown (
Vehicle control technology is being used as an interface for technology providers.
Technology providers can receive open API such as vehicle state and vehicle control, necessary for development of automated driving systems.
2.2. Outline of System Architecture on the Vehicle
The system architecture on the vehicle as a premise is shown (
The target vehicle of this document will adopt the physical architecture of using CAN for the bus between ADS and VCIB. In order to realize each API in this document, the CAN frames and the bit assignments are shown in the form of “bit assignment chart” as a separate document.
2.3. Outline of power supply architecture on the vehicle
The power supply architecture as a premise is shown as follows (
The blue colored parts are provided from an ADS provider. And the orange colored parts are provided from the VP.
The power structure for ADS is isolate from the power structure for VP. Also, the ADS provider should install a redundant power structure isolated from the VP.
3. Safety Concept
3.1. Overall Safety Concept
The basic safety concept is shown as follows.
The strategy of bringing the vehicle to a safe stop when a failure occurs is shown as follows (
1. After occurrence of a failure, the entire vehicle executes “detecting a failure” and “correcting an impact of failure” and then achieves the safety state 1.
2. Obeying the instructions from the ADS, the entire vehicle stops in a safe space at a safe speed (assumed less than 0.2G).
However, depending on a situation, the entire vehicle should happen a deceleration more than the above deceleration if needed.
3. After stopping, in order to prevent slipping down, the entire vehicle achieves the safety state 2 by activating the immobilization system.
See the separated document called “Fault Management” regarding notifiable single failure and expected behavior for the ADS.
3.2. Redundancy
The redundant functionalities with Toyota's MaaS vehicle are shown.
Toyota's Vehicle Platform has the following redundant functionalities to meet the safety goals led from the functional safety analysis.
Redundant Braking
Any single failure on the Braking System doesn't cause loss of braking functionality. However, depending on where the failure occurred, the capability left might not be equivalent to the primary system's capability. In this case, the braking system is designed to prevent the capability from becoming 0.3 G or less.
Redundant Steering
Any single failure on the Steering System doesn't cause loss of steering functionality. However, depending on where the failure occurred, the capability left might not be equivalent to the primary system's capability. In this case, the steering system is designed to prevent the capability from becoming 0.3 G or less.
Redundant Immobilization
Toyota's MaaS vehicle has 2 immobilization systems, i.e. P lock and EPB. Therefore, any single failure of immobilization system doesn't cause loss of the immobilization capability. However, in the case of failure, maximum stationary slope angle is less steep than when the systems are healthy.
Redundant Power
Any single failure on the Power Supply System doesn't cause loss of power supply functionality. However, in case of the primary power failure, the secondary power supply system keeps supplying power to the limited systems for a certain time.
Redundant Communication
Any single failure on the Communication System doesn't cause loss of all the communication functionality. System which needs redundancy has physical redundant communication lines. For more detail information, see the chapter “Physical LAN architecture (in-Vehicle)”.
4. Security Concept
4.1. Outline
Regarding security, Toyota's MaaS vehicle adopts the security document issued by Toyota as an upper document.
4.2. Assumed Risks
The entire risk includes not only the risks assumed on the base e-PF but also the risks assumed for the Autono-MaaS vehicle.
The entire risk is shown as follows.
[Remote Attack]
[Modification]
4.3. Countermeasure for the Risks
The countermeasure of the above assumed risks is shown as follows.
4.3.1. The Countermeasure for a Remote Attack
The countermeasure for a remote attack is shown as follows.
Since the autonomous driving kit communicates with the center of the operation entity, end-to-end security should be ensured. Since a function to provide a travel control instruction is performed, multi-layered protection in the autonomous driving kit is required. Use a secure microcomputer or a security chip in the autonomous driving kit and provide sufficient security measures as the first layer against access from the outside. Use another secure microcomputer and another security chip to provide security as the second layer. (Multi-layered protection in the autonomous driving kit including protection as the first layer to prevent direct entry from the outside and protection as the second layer as the layer below the former)
4.3.2. The Countermeasure for a Modification
The countermeasure for a modification is shown as follows.
For measures against a counterfeit autonomous driving kit, device authentication and message authentication are carried out. In storing a key, measures against tampering should be provided and a key set is changed for each pair of a vehicle and an autonomous driving kit. Alternatively, the contract should stipulate that the operation entity exercise sufficient management so as not to allow attachment of an unauthorized kit. For measures against attachment of an unauthorized product by an Autono-MaaS vehicle user, the contract should stipulate that the operation entity exercise management not to allow attachment of an unauthorized kit.
In application to actual vehicles, conduct credible threat analysis together, and measures for addressing most recent vulnerability of the autonomous driving kit at the time of LO should be completed.
5. Function Allocation
5.1. In a Healthy Situation
The allocation of representative functionalities is shown as below (
[Function Allocation]
5.2. In a Single Failure
See the separated document called “Fault Management” regarding notifiable single failure and expected behavior for the ADS.
Though embodiments of the present disclosure have been described above, it should be understood that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2020-015720 | Jan 2020 | JP | national |
