FI129942B

FI129942B - Enhancement of map data

Info

Publication number: FI129942B
Application number: FI20195223A
Authority: FI
Inventors: Kimmo Erkkilä; Jarmo Leino
Original assignee: Eee Innovations Oy
Priority date: 2019-03-25
Filing date: 2019-03-25
Publication date: 2022-11-15
Also published as: FI20195223A1; WO2020193862A1

Abstract

According to an aspect, there is provided a computer-implemented method for enhancing map data. The method comprises applying (600) a dynamic model (106) associated with a vehicle; calculating (602), based on the dynamic model (106) of the vehicle, an effective travel distance of a wheel of the vehicle; calculating (604), based on the dynamic model (106) of the vehicle, a momentary track width; calculating (606), based on the effective travel distance of a wheel of the vehicle and the momentary track width, a momentary direction of the vehicle; calculating (608), based on the effective travel distance of the wheel and the momentary direction of the vehicle, a position of the vehicle; associating (610) the behavior of the vehicle at the position to the map data (104) at the position; and updating (612) the map data (104) at the position based on the behavior of the vehicle at the position.

Description

ENHANCEMENT OF MAP DATA

TECHNICAL FIELD

The present application relates to the field of computer systems, and more particularly to a computer-implemented method and an apparatus for enhancing map data.

BACKGROUND

Vehicle positioning is an important service for various users. The positioning may be based on utilizing satellites that provide positioning signals for a receiver installed in a vehicle. Based on the received positioning signals it is possible to establish a current — location of the vehicle and to display the location for a driver, for example, by using a map application.

One of the problems associated with the satellite based positioning service is that the positioning is not very accurate and the accuracy varies depending on the surrounding conditions (for example, tall buildings may reduce the accuracy). Further, satellite based positioning works well only outdoors, therefore making it unusable indoors.

In addition to drawbacks relating to inaccurate positioning, map data relating to roads is simple as it basically tells only where the roads are located. Thus, the map data fails to provide any additional information about the roads.

US 2018154723 Al discloses a self-driving vehicle with an integrated fully-active suspension system. The fully-active suspension utilizes data from one or more sensors used for autonomous driving (e.g. vision, LIDAR, GPS) in order to anticipate road

N 25 — conditions in advance. & 3 Based on the above, there is a need for a map data solution that would provide enhanced - map data.

Tr a

Q 30 SUMMARY io This summary is provided to introduce a selection of concepts in a simplified form that > are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. 1

It is an object of the invention to provide a solution that would enable providing enhanced map data.

This objective is achieved by the features of the independent claims. Further embodiments and examples of the invention are apparent from the dependent claims, the description and the figures.

According to a first aspect, there is provided a computer-implemented method for enhancing map data. The method comprises applying a dynamic model associated with a vehicle, the dynamic model having been determined by obtaining status information from at least one information bus of the vehicle, the status information providing real-time status information about the vehicle, obtaining, based on vehicle identity information, vehicle dynamics information, obtaining map data representing road characteristics of roads of a geographical area, the map data comprising two-dimensional road map data, three-dimensional road map data associated with the roads, and road characteristics data, analyzing behavior of the vehicle based on the status information and the vehicle dynamics information, and computing a dynamic model for the vehicle by comparing the behavior of the vehicle to the map data, the dynamic model providing a presumed — behavior of the vehicle in various driving conditions; calculating, based on the dynamic model of the vehicle, an effective travel distance of a wheel of the vehicle; calculating, based on the dynamic model of the vehicle, a momentary track width; calculating, based on the effective travel distance of a wheel of the vehicle and the momentary track width, a momentary direction of the vehicle; calculating, based on the effective travel distance

N 25 of the wheel and the momentary direction of the vehicle, a position of the vehicle;

N associating the behavior of the vehicle at the position to the map data at the position; and 3 updating the map data at the position based on the behavior of the vehicle at the position.

E In a further implementation form of the first aspect, the status information comprises at © 30 least one of a motor power, tyre speeds, a steering wheel position, vehicle system io information, traction control information, vehicle stabilization system information and > anti-lock braking system information. 2

In a further implementation form of the first aspect, obtaining, based on vehicle identity information, vehicle dynamics information comprises obtaining initial vehicle dynamics information associated with a model or type of the vehicle from at least one external data source.

In a further implementation form of the first aspect, obtaining, based on vehicle identity information, vehicle dynamics information comprises obtaining supplemental vehicle dynamics information based on real-time vehicle dynamics data obtained from the vehicle. The vehicle identity information may be the real vehicle identification number (VIN) information of the vehicle, or plain unique reference which can be used to match the vehicle history and calibration values together.

In a further implementation form of the first aspect, the road characteristics data comprises at least one of road quality data, road irregularity data and data about local deviations associated with the road.

In a further implementation form of the first aspect, the method further comprises combining the dynamic model with the road characteristics data to enhance the calculation of the position of the vehicle.

In a further implementation form of the first aspect, the three-dimensional road map data comprises road inclination data, and the method further comprises combining the dynamic model with the road inclination data to enhance the calculation of the position of the vehicle.

S >?

N In a further implementation form of the first aspect, the method further comprises 3 comparing an expected behavior of the vehicle at the position to the behavior of the - vehicle at the position; calculating road inclination at the position based on the

E comparison; and updating road inclination at the position in the map data based on the © 30 calculated road inclination.

N

3 > In a further implementation form of the first aspect, the method further comprises dividing a road section of the map data into road segments; comparing an expected behavior of the vehicle at positions within a road segment to the behavior of the vehicle at the positions 3 within the road segment; calculating an average road inclination for the road segment based on the comparison; and updating the average road inclination for the road segment in the map data based on the calculated average road inclination.

In a further implementation form of the first aspect, the method further comprises determining an average roughness for a road segment based on an amplitude of momentary speed changes of wheels of the vehicle; and updating the map data for the road segment with the average roughness of the road segment.

In a further implementation form of the first aspect, the method further comprises detecting amplitude changes of momentary speed changes of wheels of the vehicle in a road segment; determining, based on the amplitude changes, degree of at least one road surface irregularity associated with the road segment; and updating the map data based on the degree of at least one irregularity associated with the road segment.

In a further implementation form of the first aspect, the method further comprises calculating a sensitivity dependency for the vehicle, the sensitivity dependency being dependent on speed and mass of the vehicle; comparing the sensitivity dependency of the vehicle to a sensitivity dependency of at least one other vehicle; and calibrating the sensitivity dependencies of the vehicles based on the comparison.

According to a second aspect, there is provided an apparatus for enhancing map data. The apparatus comprises at least one processor and at least one memory connected to the at least one processor. The at least one memory stores program instructions that, when

N 25 executed by the at least one processor, cause the apparatus to apply a dynamic model

N associated with a vehicle, the dynamic model having been determined by obtaining status 3 information from at least one information bus of the vehicle, the status information - providing real-time status information about the vehicle, obtaining, based on vehicle

E identity information, vehicle dynamics information, obtaining map data representing road © 30 characteristics of roads of a geographical area, the map data comprising two-dimensional io road map data, three-dimensional road map data associated with the roads, and road > characteristics data, analyzing behavior of the vehicle based on the status information and the vehicle dynamics information, and computing a dynamic model for the vehicle by comparing the behavior of the vehicle to the map data, the dynamic model providing a 4 presumed behavior of the vehicle in various driving conditions; calculate, based on the dynamic model of the vehicle, an effective travel distance of a wheel of the vehicle; calculate, based on the dynamic model of the vehicle, a momentary track width; calculate, based on the effective travel distance of a wheel of the vehicle and the momentary track width, a momentary direction of the vehicle; calculate, based on the effective travel distance of the wheel and the momentary direction of the vehicle, a position of the vehicle; associate the behavior of the vehicle at the position to the map data at the position; and update the map data at the position based on the behavior of the vehicle at the position.

In a further implementation form of the second aspect, the status information comprises at least one of a motor power, tyre speeds, a steering wheel position, vehicle system information, traction control information, vehicle stabilization system information and anti-lock braking system information.

In a further implementation form of the second aspect, obtaining, based on vehicle identity information, vehicle dynamics information comprises obtaining initial vehicle dynamics information associated with a model or type of the vehicle from at least one external data source.

In a further implementation form of the second aspect, obtaining, based on vehicle identity information, vehicle dynamics information comprises obtaining supplemental vehicle dynamics information based on real-time vehicle dynamics data obtained from the vehicle. The vehicle identity information may be the real vehicle identification number (VIN) information of the vehicle, or plain unique reference which can be used to

N 25 — match the vehicle history and calibration values together. & 3 In a further implementation form of the second aspect, the road characteristics data - comprises at least one of road guality data, road irregularity data and data about local

E deviations associated with the road.

S 30

O In a further implementation form of the second aspect, the at least one memory stores > program instructions that, when executed by the at least one processor, cause the apparatus to combine the dynamic model with the road characteristics data to enhance the calculation of the position of the vehicle. 5

In a further implementation form of the second aspect, the three-dimensional road map data comprises road inclination data, and the method further comprises combining the dynamic model with the road inclination data to enhance the calculation of the position of the vehicle.

In a further implementation form of the second aspect, the at least one memory stores program instructions that, when executed by the at least one processor, cause the apparatus to compare an expected behavior of the vehicle at the position to the behavior of the vehicle at the position; calculate road inclination at the position based on the comparison; and update road inclination at the position in the map data based on the calculated road inclination.

In a further implementation form of the second aspect, the at least one memory stores — program instructions that, when executed by the at least one processor, cause the apparatus to divide a road section of the map data into road segments; compare an expected behavior of the vehicle at positions within a road segment to the behavior of the vehicle at the positions within the road segment; calculate an average road inclination for the road segment based on the comparison; and update average road inclination for the road segment in the map data based on the calculated average road inclination.

In a further implementation form of the second aspect, the at least one memory stores program instructions that, when executed by the at least one processor, cause the apparatus to determine an average roughness for a road segment based on an amplitude

N 25 — of momentary speed changes of wheels of the vehicle; and update the map data for the

N road segment with the average roughness of the road segment. & - In a further implementation form of the second aspect, the at least one memory stores

E program instructions that, when executed by the at least one processor, cause the © 30 apparatus to detect amplitude changes of momentary speed changes of wheels of the io vehicle in a road segment; determine, based on the amplitude changes, degree of at least > one road surface irregularity associated with the road segment; and update the map data based on the degree of at least one irregularity associated with the road segment. 6

In a further implementation form of the second aspect, the at least one memory stores program instructions that, when executed by the at least one processor, cause the apparatus to calculate a sensitivity dependency for the vehicle, the sensitivity dependency being dependent on speed and mass of the vehicle, compare the sensitivity dependency of the vehicle to a sensitivity dependency of at least one other vehicle; and calibrate the sensitivity dependencies of the vehicles based on the comparison.

According to a third aspect, a computer program is provided. The computer program comprises instructions which, when the program is executed by a computer, cause the — computer to carry out the method of any the first aspect.

According to a fourth aspect, a computer-readable medium is provided. The computer- readable medium comprises instructions which when, executed by a computer, cause the computer to carry out the method of the first aspect.

According to a fifth aspect, there is provided an apparatus for enhancing map data. The apparatus comprises at least one processor configured to apply a dynamic model associated with a vehicle, the dynamic model having been determined by obtaining status information from at least one information bus of the vehicle, the status information providing real-time status information about the vehicle, obtaining, based on vehicle identity information, vehicle dynamics information, obtaining map data representing road characteristics of roads of a geographical area, the map data comprising two-dimensional road map data, three-dimensional road map data associated with the roads, and road characteristics data, analyzing behavior of the vehicle based on the status information and

N 25 — the vehicle dynamics information, and computing a dynamic model for the vehicle by

N comparing the behavior of the vehicle to the map data, the dynamic model providing a 3 presumed behavior of the vehicle in various driving conditions; calculate, based on the - dynamic model of the vehicle, an effective travel distance of a wheel of the vehicle;

E calculate, based on the dynamic model of the vehicle, a momentary track width; calculate, © 30 based on the effective travel distance of a wheel of the vehicle and the momentary track io width, a momentary direction of the vehicle; calculate, based on the effective travel > distance of the wheel and the momentary direction of the vehicle, a position of the vehicle; associate the behavior of the vehicle at the position to the map data at the position; and update the map data at the position based on the behavior of the vehicle at the position. 7

According to a sixth aspect, there is provided an apparatus for enhancing map data. The apparatus comprises means for applying a dynamic model associated with a vehicle, the dynamic model having been determined by obtaining status information from at least one information bus of the vehicle, the status information providing real-time status information about the vehicle, obtaining, based on vehicle identity information, vehicle dynamics information, obtaining map data representing road characteristics of roads of a geographical area, the map data comprising two-dimensional road map data, three- dimensional road map data associated with the roads, and road characteristics data, analyzing behavior of the vehicle based on the status information and the vehicle dynamics information, and computing a dynamic model for the vehicle by comparing the behavior of the vehicle to the map data, the dynamic model providing a presumed behavior of the vehicle in various driving conditions; means for calculating, based on the dynamic model of the vehicle, an effective travel distance of a wheel of the vehicle; means — for calculating, based on the dynamic model of the vehicle, a momentary track width; means for calculating, based on the effective travel distance of a wheel of the vehicle and the momentary track width, a momentary direction of the vehicle; means for calculating, based on the effective travel distance of the wheel and the momentary direction of the vehicle, a position of the vehicle; means for associating the behavior of the vehicle at the position to the map data at the position; and means for updating the map data at the position based on the behavior of the vehicle at the position.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following examples are described in more detail with reference to the attached

N 25 — figures and drawings, in which: & 3 FIG. 1 illustrates a block diagram representing information based on which it is possible - to determine and model behavior of a vehicle. i © 30 FIG. 2 illustrates a flow diagram of a method for modelling dynamics of a vehicle.

N

3 > FIG. 3 illustrates calculation of the change of wheel normal load caused by the road longitudinal inclination in front and rear axles. 8

FIG. 4 illustrates a computer-implemented method for positioning a vehicle.

FIGS. SA and 5B illustrate graphs associated with a turning vehicle.

FIG. 6 illustrates a computer-implemented method for enhancing map data.

FIG. 7 illustrates examples of possible irregularities associated with a road.

FIG. 8 illustrates a system diagram depicting an exemplary apparatus according to an — aspect.

In the following identical reference signs refer to identical or at least functionally eguivalent features.

DETAILED DESCRIPTION

In the following description, reference is made to the accompanying drawings, which form part of the disclosure, and in which are shown, by way of illustration, specific aspects and examples in which the present invention may be placed. It is understood that other aspects may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, as the scope of the present invention is defined be the appended claims.

For instance, it is understood that a disclosure in connection with a described method may

N 25 — also hold true for a corresponding device or system configured to perform the method and & vice versa. For example, if a specific method step is described, a corresponding device 3 may include a unit or other means to perform the described method step, even if such unit - is not explicitly described or illustrated in the figures. On the other hand, for example, if

E a specific apparatus is described based on functional units, a corresponding method may © 30 include a step performing the described functionality, even if such step is not explicitly

N . . . os

O described or illustrated in the figures. Further, it is understood that the features of the > various exemplary aspects described herein may be combined with each other, unless specifically noted otherwise. 9

FIG. 1 illustrates a block diagram representing information based on which it is possible to determine and model behavior of a vehicle. Vehicle status information 100 refers to information that can be obtained from the vehicle itself, for example, via one or more information buses of the vehicle while the vehicle is in use. The vehicle status information comprises, for example, at least one of motor power, tyre speeds, a steering wheel position, vehicle system information, traction control information, vehicle stabilization system information and anti-lock braking system information.

Vehicle dynamics information 102 may be obtained based on vehicle identity information, for example, from one or more external data sources. If no vehicle specific dynamics information is not available, it is possible to use vehicle dynamics information that is common for this vehicle type. When the vehicle is used, the vehicle dynamics information may be updated based on analysis of the behavior of the vehicle. Further, vehicle dynamics information determined for a specific vehicle may be used as — preliminary knowledge for other similar vehicles. The vehicle identity information may be the real vehicle identification number (VIN) information of the vehicle, or plain unique reference which can be used to match the vehicle history and calibration values together.

Map data 104 may represent road characteristics of roads of a geographical area, and the — map data 104 may comprise two-dimensional road map data, three-dimensional road map data associated with the roads, and/or road characteristics data. The three-dimensional road map data may comprise information, for example, about road height data and road inclination data. The road characteristics data may comprise at least one of road quality data, road irregularity data and data about local deviations associated with the road. The

N 25 road characteristics data may comprise, for example, other typical dynamic behaviour

N changes that can be statistically recognized by various vehicles at the same locations. For 3 example, if a road is rutted, a weight transfer of a vehicle can be considered as “normal” - if several different vehicles experience the same weight transfer. Similarly, pits, rail z locations or other road imperfections of a road are characteristics that have an effect on © 30 how a vehicle should behave based on a current dataset associated with the vehicle.

N

3 > Based on the vehicle status information 100, vehicle dynamics information 102 and the map data 104 it is possible to determine a dynamic model for the vehicle. The dynamic model may then enable an estimation of the performance of the vehicle, observation of 10 changes associated with the vehicle and observation of changes in driving conditions of the vehicle.

FIG. 2 illustrates a computer-implemented method for modelling dynamics of a vehicle.

The vehicle may be any vehicle travelling on a road, for example, an autonomous vehicle, a passenger car, a truck, a motorcycle etc.

At 200, status information is obtained from at least one information bus of the vehicle, the status information providing status information or real-time status information about — the vehicle.

At 202, vehicle dynamics information representing vehicle dynamics is obtained based on vehicle identity information.

At 204, map data representing road characteristics of roads of a geographical area, the map data comprising two-dimensional road map data, three-dimensional road map data associated with the roads, and road characteristics data is obtained.

At206, behavior of the vehicle is analyzed based on the status information and the vehicle — dynamics information.

At 208, a dynamic model for the vehicle is calculated by comparing the behavior of the vehicle to the map data.

N 25 The dynamic model of the vehicle can be used in various applications in which an

O . oo . .

N accurate vehicle representation is needed. For example, based on the dynamic model, it © . . . CL . a

O is possible to calculate a presumed behavior of the vehicle in various driving conditions. - If an actual behavior of the vehicle deviates from the presumed behavior of the vehicle,

E this is caused either by changes in driving conditions or changes in the vehicle.

O 30

N

O The dynamic model of the vehicle may define a set of vehicle-specific calibration > parameters. These calibration parameters may represent how the vehicle behaves in various driving situations. 11

The dynamics model of the vehicle may involve a set of various parameters or calibration parameters, for example, one or more of the following: 1) a mass of the vehicle, 2) powertrain efficiency coefficient or map, 3) a track width, 4) a wheelbase, 5) location of the center of gravity, 6) the moment of inertia along different axes of the vehicle and the moment of inertia associated with rotating masses, 7) effective rolling circumferences of the wheels, 8) an effect of the circumferential force of a wheel to the rolling circumferences, and 9) overall flexibility in longitudinal and lateral directions in weight of the transition situations caused, for example, by the wheels, the car chassis structure and the car body.

The mass of the vehicle may be obtained from an external data source, it can be manually input or a mass estimation may be used based on the vehicle type. When calculating the dynamic model of the vehicle, the mass of the vehicle can be made more accurate by comparing the effect of the energy produced by a motor of the vehicle to state of motion — of the vehicle, taking into account also, for example, at least one of changes in vehicle speed, altitude changes, the amount of work performed by the motor of the vehicle, efficiencies, driving resistances and road quality factors.

In the equations below, the following parameters are used: m = mass

PE = engine power up = powertrain coefficient t = time

N 25 A=frontal area

N Cw = airdrag coefficient 3 v = speed - s = distance

E v2 = speed at point 2 0 30 — vi = speed at point I io g = gravity > ho = altitude at point 2 hi = altitude at point 1

Ur = rolling resistance 12 ua = PACw

The mass of the vehicle may be estimated as follows:

Ww = Way + Wan + Wp + wy

Pg * upt = 2m(vy — vi)? + mg(hy — hy) + M9URS + pav?S x" 1 1

PalppUAV*S * 27 3 m(va — vi)” + mg(h, — hi) + MJURS =m (; (v? — v)? + gh, — hy) + JHrS) m= PElpritav?Sis 3502-01)? +9(R2-h1)+9URS m= PElprP ACY 2S 3502-01)? +9(R2-h1)+9URS

Powertrain efficiency information may be obtained from one or more external data sources, manually or based on the vehicle type. Later, the information may be made more accurate by multivariate analysis or statistical analysis.

Track width information may be obtained from one or more external data sources, manually or based on the vehicle type. Later, the information may be made more accurate by multivariate analysis or statistical analysis.

Wheelbase information may be obtained from one or more external data sources, manually or based on the vehicle type. Later, the information may be made more accurate

N by multivariate analysis or statistical analysis. & 3 Information about the location of the center of gravity may be obtained from one or more - 25 — external data sources, manually or based on the vehicle type. Later, the information may z be made more accurate by multivariate analysis or statistical analysis.

S

O Information about the moment of inertia along different axes of the vehicle and the > moment of inertia associated with rotating masses may be obtained from one or more external data sources, manually or based on the vehicle type. Later, the information may be made more accurate by multivariate analysis or statistical analysis. 13

Effective rolling circumferences of the wheels may be calculated for each wheel by comparing the travelled distance to each other and to map data in chosen periods. For each wheel a computational dependency tied to the normal force of the wheel is generated.

A momentary normal force of the wheel takes into account a dynamic mass shift of the vehicle, also taking into account road characteristics, for example, road inclinations to different directions. The effect of speed may also be taken into account.

The effect of the circumferential force of a wheel to the rolling circumferences of the — wheels is estimated by comparing speed of rotation differences with each other with different tractive forces. The estimation may also take into account road quality characteristics and friction.

Flexibility of the wheels and the chassis in longitudinal and lateral directions in weight transition situations may be determined for each and for each wheel type by using initial values or by searching the values from a library for a similar vehicle and wheel type. The effects of the weight transition in longitudinal and lateral directions are estimated separately because a wheel of the vehicle and chassis structures act differently with forces having different directions. Coefficients representing the dynamics indicate both the change caused by the weight shift to the effective travelling device of each wheel and changes caused by the flexibility to the effective travelling distance of the wheel. The location of the effective contact point affects, for example, to the track width and wheelbase. When computing dynamic coefficients, the map data is utilized, for example, by comparing a turning degree of the vehicle according to the dynamic model in a curve

N 25 to an expected turning degree based on the map data.

O

N

3 FIG. 3 illustrates calculation of the change of wheel normal load caused by the road - longitudinal inclination in front and rear axles. Based on FIG. 3, the following equations

E can be formed:

S 30

O Fr «WB = mg = (CF + Sc) 9 Fp = e

Sc=hxtan(y) 14

Fo = Mg*(CR — Sc)

F WB

F, = mg+(CF+hstan(y))

R WB

Fo = mg#+(CR — hxtan(y))

F WB

Fyr = cos(y) * Fg

Fyr = cos(y) * Fr

Cr = Scc-r

In an embodiment, also lateral inclination and longitudal and lateral accelerations ay be calculated similarly.

FIG. 4 illustrates a computer-implemented method for positioning a vehicle. The vehicle may be any vehicle travelling on a road, for example, an autonomous vehicle, a passenger car, a truck, a motorcycle etc.

At 400, a dynamic model associated with a vehicle discussed above is applied. As already discussed, the dynamic model has been determined by obtaining status information from at least one information bus of the vehicle, the status information providing real-time status information about the vehicle, obtaining, based on vehicle identity information, vehicle dynamics information, obtaining map data representing road characteristics of roads of a geographical area, the map data comprising two-dimensional road map data, three-dimensional road map data associated with the roads, and road characteristics data, analyzing behavior of the vehicle based on the status information and the vehicle

N dynamics information, and computing a dynamic model for the vehicle by comparing the

O

N 25 — behavior of the vehicle to the map data. &

MI At 402, an effective travel distance of a wheel of the vehicle is calculated based on the

I

= dynamic model of the vehicle.

O

N

S 30 — At 404, a momentary track width is calculated based on the dynamic model of the vehicle.

O

N

15

At 406, a momentary direction of the vehicle is calculated based on the effective travel distance of a wheel of the vehicle and the momentary track width.

At 408, a position of the vehicle is calculated based on the effective travel distance of the — wheel and the momentary direction of the vehicle.

When using the dynamical model of the vehicle, it is possible to calculate an effective travel distance of the wheel of the vehicle in various changing driving conditions. If the dynamical model is not used, wheel transformations and changes in measurements used inthe position determination are not taken into account, resulting in an inaccurate position determination.

The three-dimensional road map data may comprise also road inclination. When the dynamic model and the road inclination data are combined, the position determination — can be made more accurate. For example, an effect of the road inclination to a projection of the track width can be taken into account.

In the following, exemplary equations are presented for the rear axle. Equations for the front axle may be formed similarly.

A starting value for a wheel speed difference between left and right sides by a wheel travel is ow = SAN

Vicor = VL Vp + SA% 3 25 Vrcor = VR — Vg * SA% 3 - A starting value for wheel speed change per speed can be represented as follows: = Vreor2 = Vicor — Vicor * Speedcor%

N Vrcor2 = VRcor — VRcor * Speedcor%

A 30 > The mass detection may be performed using the previously presented eguations for the

N mass of the vehicle. 16

The following parameters may be obtained from a library to be used as starting values: - TW = track width - h=masscenter height - WB = wheelbase - mass center location in x/y directions - turning inertia over x/y/z axles - TF = tyre and suspension flex in x direction (side flex) - TFC = type and suspension flex in z directon (compression flex)

The following equations can be formed, when reviewed together with FIGS. SA and 5B:

TWayn = TW + ATWayn

AT Wayn = Firat * TF — Frrtat * TF

TW dyn . mg" +hsin(0)) Scc-p+htan(y)

FNRLSTAT = TW äyn"cos (0) — * cos(y) + =:

TW a .

F N mg(- SY hsin(0)) . Scc-p+htan(y)

NRLSTAT = Tw jynscos (0) WB — —Frarrcos(x)+h+Scc—r | FLonc*h

FNRLDYN = TT TWapnWE tws

F — +FLAT*COS(&)*h*Scc-p + Frong*h

NRLDYN = ry we ws o

Viayn = Vicorzpoyn — (Fnrz * Tec * V1cor2)

Vrdyn = VRCOR2DYN € (Fare + Tec * Vrcor2)

Ro = OA TWayn * cos («)

VRdyn ”YLdyn — VYrdyntVRdyn

Väyn = — oz -—

N _ mivgy,?

N Far = Re

N

: A 3 Frone = rn *m - Ss = Vayn* t

E s a p = RC

N

N 25 Sa = J2R? — 2R?cos (B)

O

5 0=XYB

Xpos = 2 sin(0) * sqcos(y)

Ypos = 2 cos(0) * sa cos(y) 17

In the above equations, the following parameters were used: - y = road longitudinal inclination - Rc = turning circle - «=road side inclination - — Scc = distance from axle to mass center - Frat = lateral force - Fronc = longitudinal force - s=driving distance - B=turning/direction change - — Sa = position change distance between A and B - 0= direction - Xpos = position on X axis - — Yeos = position on Y axis - TWayn = dynamic track width - Farustar = tyre normal force without speed (rear left) - FarrstaT = tyre normal force without speed (rear right) - FrrrDyn = tyre normal force with dynamic weight transfer (rear left) - FrrrbDyn = tyre normal force with dynamic weight transfer (rear right) - — VLdyn = left wheel speed after dynamic corrections - — VRdyn = right wheel speed after dynamic corrections

The illustrated solution for determining the position accurately may be used in vehicle navigation and especially in real-time navigation and in real-time three-dimensional

N 25 — navigation. The illustrated solution can also be utilized in locations where a satellite

N position based signal, for example, a GPS signal, is weak on non-existent. These locations 3 may include, for example, closed parking lots, blind spots due to buildings, tunnels and - guarries. Further, the illustrated solution may provide a location service in applications in

E which a single location signal is not sufficient, for example, in autonomous vehicles,

Q 30 metros and trains.

N

3 > FIG. 6 illustrates a computer-implemented method for enhancing map data. 18

At 600, a dynamic model associated with a vehicle discussed above is applied. The vehicle may be any vehicle travelling on a road, for example, an autonomous vehicle, a passenger car, a truck, a motorcycle etc. As already discussed, the dynamic model has been determined by obtaining status information from at least one information bus of the — vehicle, the status information providing real-time status information about the vehicle, obtaining, based on vehicle identity information, vehicle dynamics information, obtaining map data representing road characteristics of roads of a geographical area, the map data comprising two-dimensional road map data, three-dimensional road map data associated with the roads, and road characteristics data, analyzing behavior of the vehicle based on — the status information and the vehicle dynamics information, and computing a dynamic model for the vehicle by comparing the behavior of the vehicle to the map data.

At 602, an effective travel distance of a wheel of the vehicle is calculated based on the dynamic model of the vehicle.

At 604, a momentary track width is calculated based on the dynamic model of the vehicle.

At 606, a momentary direction of the vehicle is calculated based on the effective travel distance of a wheel of the vehicle and the momentary track width.

At 608, a position of the vehicle is calculated based on the effective travel distance of the wheel and the momentary direction of the vehicle.

At 610, the behavior of the vehicle at the position is associated to the map data at the

N 25 — position. & 3 At 612, the map data at the position is updated based on the behavior of the vehicle at the - position. = a © 30 — When the dynamic model of the vehicle and an accurate position of the vehicle has been io determined, various observations about the behavior of the vehicle can be accurately > linked to the map, for example, to exact map coordinates. Further, a geometry of a road or road segment may be supplemented with information about road inclinations, road 19 grooves and other errors and/or deviations. Further, the updated map data may be used as an enhanced map with all other vehicles travelling the same road or road segment later.

In one embodiment, an expected behavior based on the dynamic model of the vehicle at the calculated position may be compared to the actual behavior of the vehicle at the position. When the vehicle travels on a straight road, road inclination causes a weight shift for the vehicle. This, in turn, has an effect for the effective travel distance of a wheel.

Road inclination at the position of the vehicle can be calculated based on the comparison.

Further, now that the accurate position of the vehicle is known and the road inclination at — the position of the vehicle are known, road inclination at the position in the map data can be updated based on the calculated road inclination.

In an embodiment, a road or a road section of the map data may be divided into road segments. The division may be based on, for example, the fact how a dynamic state of — the vehicle changes. As one possible example, the road or road sections may be divided into bends, straight parts, inclination changes etc. An expected behavior of the vehicle at positions within a road segment may be compared to the behavior of the vehicle at the positions within the road segment, and an average road inclination may be calculated for the road segment based on the comparison. Now that the average road inclination for the road segment is known, the average road inclination for the road segment may be updated in the map data.

Within a specific road segment, momentary road inclinations may be calculated similarly.

Due to this, accurate inclination data can be calculated for the road section at all travelled

N 25 — positions. & 3 In an embodiment, several vehicles may provide their behavior data about the same road - or road segment. As different vehicles may travel a slightly different path along a specific

E road or road section, the map data may be enhanced even more to over a more complete © 30 — part of the road or road section. Further, as different vehicles travel similar paths along io the road or road section, road inclination data provided by different vehicles is verified. > In one embodiment, the map data may be enhanced with the calculated road inclination data after a predetermined number of vehicles have travelled the road or road section and the analysis results have been verified. 20

Further, in one embodiment, an average roughness for a road segment may be determined based on an amplitude of momentary speed changes of wheels of the vehicle obtained based on analyzing the behavior of the vehicle when it has travelled along the road segment. The map data for the road segment may then be updated with the average roughness of the road segment. The average roughness may give, for example, valuable information about the overall condition of the road segment.

In one embodiment, the behavior of the vehicle and/or the dynamic model of the vehicle ca also used in determining quality attributes associated with a road or road segment.

Amplitude changes of momentary speed changes of wheels of the vehicle in a road segment may be detected. Based on the amplitude changes, degree of at least one road surface irregularity associated with the road segment may be determined. The map data may then be updated based on the degree of at least one irregularity associated with the — road segment. In other words, potholes and bumps and their degree and/or severity may be determined based on the amplitude changes.

Further, in one embodiment, a sensitivity dependency maybe calculated for the vehicle, the sensitivity dependency being dependent on speed and mass of the vehicle. Different — vehicles can then act as “road sensors”, where each sensor may provide a different speed change response for a same pothole or bump of a specific road position. Thus, by comparing the sensitivity dependency of the vehicle to a sensitivity dependency of at least one other vehicle, the sensitivity dependencies of the vehicles may be calibrated based on the comparison. After the calibration, results of different vehicles can be compared

N 25 — against each other. & 3 In one embodiment, vehicle behavior analysis may be performed by wheel basis of a - single vehicle. By analyzing each wheel separately, it is possible to determine which

E wheels of the vehicle, i.e. which side of the vehicle, travelled over an irregularity © 30 associated with the road segment. This also enables determination of an accurate position io of the irregularity in the road segment.

N

FIG. 7 illustrates examples of possible irregularities associated with a road. The y axis represents wheel speed percentual impulse. The x axis represents a wheel speed message 21 count. The wheel speed percentual impulse represents a relative speed change as a percentage. This may mean, for example, that the larger speed change experienced by a wheel in a pothole or other road irregularity of a road, the larger the pothole or other road irregularity is in the road.

References 700 and 704 identify specific holes or potholes in an analyzed position in a road or road segment. A higher reading in the y axis indicated a more severe hole or pothole. References 702 and 712 identifies a more general section of the road or road segment, for example, gravel. A reference 706 identifies a normal asphalt section of the road or road segment. As can be seen from FIG. 7, values in the y axis are the lowest in the asphalt section. This means that the asphalt section is the smoothest surface in this example. A reference 706 identifies a wide turn out of the road. A reference 710 identifies a minor bump in a repaired asphalt on the right side of the vehicle. Finally, a reference 714 identifies a bumpy home road section.

FIG. 8 illustrates a system diagram depicting an exemplary apparatus 800 including a variety of optional hardware and software components, shown generally at 812. Any components 812 in the apparatus can communicate with any other component, although not all connections are shown, for ease of illustration. The apparatus 800 can be any of a variety of computing devices (for example, a computer, a cloud based server etc.) and can allow two-way communications with one or more communications networks, such as the

Internet.

The illustrated apparatus 800 can include one or more controllers or processors 802 (e.g,

N 25 — signal processor, microprocessor, ASIC, or other control and processing logic circuitry)

N for performing such tasks as signal coding, data processing, input/output processing, 3 power control, and/or other functions. An operating system 808 can control the allocation - and usage of the components 812 and support for one or more application programs 810.

E The application programs can include common computing applications (e.g., server © 30 software), or any other computing application.

N

3

IN The illustrated apparatus 800 can include a memory 804. The memory 804 can include non-removable memory and/or removable memory. The non-removable memory can include RAM, ROM, flash memory, a hard disk, or other well-known memory storage 22 technologies. The removable memory can include flash memory or other well-known memory storage technologies. The memory 804 can be used for storing data and/or code for running the operating system 808 and the applications 810. Example data can include web pages, text, images, sound files, video data, or other data sets to be sent to and/or received from one or more network servers or other devices via one or more wired or wireless networks.

The apparatus 800 can further include at least one physical connector, which can be a

USB port, IEEE 1394 (FireWire) port, and/or RS-232 port etc.

The illustrated components 812 are not required or all-inclusive, as any components can deleted and other components can be added.

The apparatus 800 may be configured to implement the various features, examples and embodiments illustrated in FIGS. 1-4 partially or completely. The functionality described herein can be performed, at least in part, by one or more computer program product components such as software components. According to an example, the processor 802 may be configured by the program code which when executed performs the examples and embodiments of the operations and functionality described. Alternatively, or in addition, — the functionality described herein can be performed, at least in part, by one or more hardware logic components. For example, and without limitation, illustrative types of hardware logic components that can be used include Field-programmable Gate Arrays (FPGAs), Program-specific Integrated Circuits (ASICs), Program-specific Standard

Products (ASSPs), System-on-a-chip systems (SOCs), Complex Programmable Logic

N 25 — Devices (CPLDs), Graphics Processing Units (GPUs).

O

N

3 Further, one or more of the disclosed elements or components of the apparatus 800 may - constitute means for applying a dynamic model associated with the vehicle, the dynamic

E model having been determined by obtaining status information from at least one © 30 information bus of the vehicle, the status information providing real-time status io information about the vehicle, obtaining, based on vehicle identity information, vehicle > dynamics information, obtain map data representing road characteristics of roads of a geographical area, the map data comprising two-dimensional road map data, three- dimensional road map data associated with the roads, and road characteristics data, 23 analyzing behavior of the vehicle based on the status information and the vehicle dynamics information, and computing a dynamic model for the vehicle by comparing the behavior of the vehicle to the map data; means for calculating based on the dynamic model of the vehicle, an effective travel distance of a wheel of the vehicle; means for calculating, based on the dynamic model of the vehicle, a momentary track width; means for calculating, based on the effective travel distance of a wheel of the vehicle and the momentary track width, a momentary direction of the vehicle; means for calculating, based on the effective travel distance of the wheel and the momentary direction of the vehicle, a position of the vehicle, means for associating the behavior of the vehicle at the — position to the map data at the position; and means for updating the map data at the position based on the behavior of the vehicle at the position.

The functionality of the apparatus 800 may be implemented by program instructions stored on a computer readable medium. The program instructions, when executed, cause — the computer, processor or the like, to perform the disclosed steps or functionality. The computer readable medium can be any medium, including non-transitory storage media, on which the program is stored such as a Blu-Ray disc, DVD, CD, USB (flash) drive, hard disc, server storage available via a network, a ROM, a PROM, an EPROM, an

EEPROM or a Flash memory having electronically readable control signals stored thereon which cooperate or are capable of cooperating with a programmable computer system such that an embodiment of at least one of the inventive methods is performed.

An embodiment of the invention comprises or is a computer program comprising program code for performing any of the methods described herein, when executed on a computer.

Another example of the invention comprises or is a computer readable medium

N 25 comprising a program code that, when executed by a processor, causes an apparatus to

N perform any of the methods described herein. & - In one embodiment, the apparatus 800 comprises a vehicle navigator apparatus. The

E vehicle navigator device may receive the status information from at least one information © 30 bus of the vehicle. Then, the vehicle navigator device may comprise the dynamical model io of the vehicle, and the dynamical model may calculate the actual direction and speed of > the vehicle based on the vehicle dynamics information and the map data. By applying the illustrated solution, the vehicle navigator apparatus always stays on a correct driving lane. 24

Further, the illustrated solution also removes the problem of determining of a correct direction, for example, when driving in cities.

Although the subject matter has been described in language specific to structural features and/or acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as examples of implementing the claims and other equivalent features and acts are intended to be within the scope of the claims.

It will be understood that the benefits and advantages described above may relate to one example or may relate to several examples. The examples are not limited to those that solve any or all of the stated problems or those that have any or all of the stated benefits and advantages. It will further be understood that reference to 'an' item may refer to one or more of those items.

The steps of the methods described herein may be carried out in any suitable order, or simultaneously where appropriate. Additionally, individual blocks may be deleted from any of the methods without departing from the spirit and scope of the subject matter described herein. Aspects of any of the examples described above may be combined with aspects of any of the other examples described to form further examples without losing the effect sought.

The term 'comprising' is used herein to mean including the method, blocks or elements

N 25 identified, but that such blocks or elements do not comprise an exclusive list and a method

N or apparatus may contain additional blocks or elements. & - Although the invention and its advantages have been described in detail with reference to

E specific features and embodiments thereof, it is evident that various changes, © 30 modifications, substitutions, combinations and alterations can be made thereto without io departing from the spirit and scope of the invention as defined by the appended claims. > The specification and drawings are, accordingly, to be regarded simply as an illustration of the invention as defined by the appended claims, and are contemplated to cover any and all modifications, variations, combinations or equivalents that fall within the scope of the present invention.

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26

Claims

1. A computer-implemented method for enhancing map data, characterized in that the method comprises: applying (600) a dynamic model (106) associated with a vehicle, the dynamic model (106) having been determined by obtaining (200) status information (100) from at least one information bus of the vehicle, the status information (100) providing real-time status information about the vehicle, obtaining (202), based on vehicle identity information, vehicle dynamics information (102), obtaining (204) map data (104) representing road characteristics of roads of a geographical area, the map data (104) comprising two-dimensional road map data, three-dimensional road map data associated with the roads, and road characteristics data, analyzing (206) behavior of the vehicle based on the status information (100) and the vehicle dynamics information (102), and computing the dynamic model (106) for the vehicle by comparing the behavior of the — vehicle to the map data (104), the dynamic model (106) providing a presumed behavior of the vehicle in various driving conditions; calculating (602), based on the dynamic model (106) of the vehicle, an effective travel distance of a wheel of the vehicle; calculating (604), based on the dynamic model (106) of the vehicle, a momentary track width; calculating (606) , based on the effective travel distance of a wheel of the vehicle and the momentary track width, a momentary direction of the vehicle; calculating (608), based on the effective travel distance of the wheel and the momentary direction of the vehicle, a position of the vehicle; N 25 associating (610) the behavior of the vehicle at the position to the map data (104) N at the position; and 3 updating (612) the map data (104) at the position based on the behavior of the - vehicle at the position. x a © 30

2. A method of claim 1, wherein the status information (100) comprises at io least one of a motor power, tyre speeds, a steering wheel position, vehicle system > information, traction control information, vehicle stabilization system information and anti-lock braking system information. 27

3. A method of claim 1 or 2, wherein obtaining, based on vehicle identity information, vehicle dynamics information (102) comprises obtaining initial vehicle dynamics information associated with a model or type of the vehicle from at least one external data source.

4. A method of claim 1 or 3, wherein obtaining, based on vehicle identity information, vehicle dynamics information (102) comprises obtaining supplemental vehicle dynamics information based on real-time vehicle dynamics data obtained from the vehicle.

5. A method of any of claims 1 - 4, wherein the road characteristics data comprises at least one of road guality data, road irregularity data and data about local deviations associated with the road.

6. A method of any of claim 5, wherein the method further comprises combining the dynamic model (106) with the road characteristics data to enhance the calculation of the position of the vehicle.

7. A method of any of claims 1 - 6, wherein the three-dimensional road map data comprises road inclination data, and the method further comprises combining the dynamic model (106) with the road inclination data to enhance the calculation of the position of the vehicle.

8. A method of any of claims 1 — 7, further comprising: N 25 comparing an expected behavior of the vehicle at the position to the behavior of N the vehicle at the position; 3 calculating road inclination at the position based on the comparison; and - updating road inclination at the position in the map data based on the calculated z road inclination. S 30

O 9. A method of any of claims 1 — 8, further comprising: > dividing a road section of the map data into road segments; comparing an expected behavior of the vehicle at positions within a road segment to the behavior of the vehicle at the positions within the road segment; and 28 calculating an average road inclination for the road segment based on the comparison; and updating the average road inclination for the road segment in the map data based on the calculated average road inclination.

10. A method of any of claims 1 — 9, further comprising: determining an average roughness for a road segment based on an amplitude of momentary speed changes of wheels of the vehicle; and updating the map data (104) for the road segment with the average roughness of the road segment.

11. A method of any of claims 1 — 10, further comprising: detecting amplitude changes of momentary speed changes of wheels of the vehicle in a road segment; determining, based on the amplitude changes, degree of at least one road surface irregularity associated with the road segment; and updating the map (104) data based on the degree of at least one irregularity associated with the road segment.

12. A method of claim 11, further comprising: calculating a sensitivity dependency for the vehicle, the sensitivity dependency being dependent on speed and mass of the vehicle; comparing the sensitivity dependency of the vehicle to a sensitivity dependency of at least one other vehicle; and N 25 calibrating the sensitivity dependencies of the vehicles based on the comparison. O N 3 13. An apparatus (800) for enhancing map data, the apparatus (800) - comprising: E at least one processor (802); © 30 at least one memory (804) connected to the at least one processor (802); io characterized in that the at least one memory (804) stores program > instructions that, when executed by the at least one processor (802), cause the apparatus (800) to: 29 apply (600) a dynamic model (106) associated with a vehicle, the dynamic model (106) having been determined by obtaining (200) status information (100) from at least one information bus of the vehicle, the status information (100) providing real-time status information about the vehicle, obtaining (202), based on vehicle identity information, — vehicle dynamics information (102), obtaining (204) map data (104) representing road characteristics of roads of a geographical area, the map data (104) comprising two- dimensional road map data, three-dimensional road map data associated with the roads, and road characteristics data, analyzing (206) behavior of the vehicle based on the status information (100) and the vehicle dynamics information (102), and computing (208) the dynamic model (106) for the vehicle by comparing the behavior of the vehicle to the map data (104), the dynamic model (106) providing a presumed behavior of the vehicle in various driving conditions; calculate (602), based on the dynamic model (106) of the vehicle, an effective travel distance of a wheel of the vehicle; calculate (604), based on the dynamic model (106) of the vehicle, a momentary track width; calculate (606), based on the effective travel distance of a wheel of the vehicle and the momentary track width, a momentary direction of the vehicle; calculate (608), based on the effective travel distance of the wheel and the momentary direction of the vehicle, a position of the vehicle; associate (610) the behavior of the vehicle at the position to the map data (104) at the position; and update (612) the map data (104) at the position based on the behavior of the vehicle at the position.

S >? N 14. An apparatus of claim 13, wherein the status information comprises at 3 least one of a motor power, tyre speeds, a steering wheel position, vehicle system - information, traction control information, vehicle stabilization system information and E anti-lock braking system information.

S 30 O 15. — An apparatus (800) of claim 13 or 14, wherein obtaining, based on vehicle > identity information, vehicle dynamics information (102) comprises obtaining initial vehicle dynamics information associated with a model or type of the vehicle from at least one external data source.

16. — An apparatus (800) of claim 13 or 15, wherein obtaining, based on vehicle identity information, vehicle dynamics information (102) comprises obtaining supplemental vehicle dynamics information based on real-time vehicle dynamics data obtained from the vehicle.

17. An apparatus (800) of any of claims 13 - 16, wherein the road characteristics data comprises at least one of road quality data, road irregularity data and data about local deviations associated with the road.

18. An apparatus (800) of any of claim 17, wherein the at least one (804) memory stores program instructions that, when executed by the at least one processor (802), cause the apparatus (800) to combine the dynamic model (106) with the road characteristics data to enhance the calculation of the position of the vehicle.

19. An apparatus (800) of any of claims 13 - 18, wherein the three-dimensional road map data comprises road inclination data, and the method further comprises combining the dynamic model (106) with the road inclination data to enhance the calculation of the position of the vehicle.

20. — An apparatus (800) of any of claims 13 — 19, wherein the at least one memory (804) stores program instructions that, when executed by the at least one processor (802), cause the apparatus (800) to: compare an expected behavior of the vehicle at the position to the behavior of the N 25 vehicle at the position; N calculate road inclination at the position based on the comparison; and 3 update road inclination at the position in the map data based on the calculated road - inclination. Tr a © 30 21. An apparatus (800) of any of claims 13 — 20, wherein the at least one io memory (804) stores program instructions that, when executed by the at least one > processor (802), cause the apparatus (800) to: divide a road section of the map data into road segments; 31 compare an expected behavior of the vehicle at positions within a road segment to the behavior of the vehicle at the positions within the road segment; and calculate an average road inclination for the road segment based on the comparison; and update average road inclination for the road segment in the map data based on the calculated average road inclination.

22. An apparatus (800) of any of claims 13 — 21, wherein the at least one memory (804) stores program instructions that, when executed by the at least one — processor (802), cause the apparatus (800) to: determine an average roughness for a road segment based on an amplitude of momentary speed changes of wheels of the vehicle; and update the map data for the road segment with the average roughness of the road segment.

23. An apparatus (800) of any of claims 13 — 22, wherein the at least one memory (804) stores program instructions that, when executed by the at least one processor (802), cause the apparatus (800) to: detect amplitude changes of momentary speed changes of wheels of the vehicle in aroad segment; determine, based on the amplitude changes, degree of at least one road surface irregularity associated with the road segment; and update the map data based on the degree of at least one irregularity associated with the road segment. N 25 N 24. — An apparatus (800) of claim 23, wherein the at least one memory (804) 3 stores program instructions that, when executed by the at least one processor (802), cause - the apparatus (800) to: E calculate a sensitivity dependency for the vehicle, the sensitivity dependency © 30 being dependent on speed and mass of the vehicle; io compare the sensitivity dependency of the vehicle to a sensitivity dependency of > at least one other vehicle; and calibrate the sensitivity dependencies of the vehicles based on the comparison. 32

25. A computer program comprising program code which, when the program is executed by a computer, cause the computer to carry out the method of any of claims 1-12.

26. A computer-readable medium comprising instructions which when, executed by a computer, cause the computer to carry out the method of any of claims 1 —