EP2388753A1

EP2388753A1 - A digital tachograph and a method therefore

Info

Publication number: EP2388753A1
Application number: EP10163231A
Authority: EP
Inventors: Martin Wennerblom
Original assignee: Stoneridge Electronics AB
Current assignee: Stoneridge Electronics AB
Priority date: 2010-05-19
Filing date: 2010-05-19
Publication date: 2011-11-23

Abstract

The present invention relates to a digital tachograph, and a method for a tachograph, comprising motion collection means for collecting a vehicle speed value, vehicle speed limit collection means for collecting a vehicle speed limit, a second speed limit collection means for collecting a second speed limit value, e.g. road speed limit, driver speed limit or cargo speed limit. The tachograph also comprises speed limit management means for register a speed limit break if the speed of the vehicle exceeds one of the speed limit values.

Description

FIELD OF INVENTION

The present invention relates generally to digital tachographs and particularly to a digital tachograph comprising speed limit functions.

BACKGROUND

Digital tachographs are like analogue tachographs used for gathering information relating to the usage of a vehicle, and to collection of driver activities, such as driving hours, distance traveled, start time, finish time, rest time, driver identity, starting location and finishing location. Tachograph registers and saves actions and data and associates them to the identified driver, time and place. In Europe a digital tachograph is partly defined by European Community legislation.
The existing tachograph of today can not handle all information that could be of importance for the driver, the owner of the vehicle or the public. The aim of the invention is to provide such a tachograph.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a tachograph and a method for handling speed limits.
This object, among others, is according to the present invention attained by a digital tachograph and a method, respectively, as defined by the appended claims.
The tachograph comprises normal tachograph functions such as the possibilities to measure speed of the vehicle in which it is installed. This is done by motion collection means which collect a vehicle speed value, i.e. the speed of the vehicle. The tachograph further comprises vehicle speed limit collection means for collecting a first speed limit value, the vehicle speed limit, and a second speed limit collection means for collecting at least a second speed limit value, e.g. road speed limit, driver speed limit or cargo speed limit. The invention further introduces speed limit management means for register a speed limit break if the speed of the vehicle exceeds one of the speed limit values.
The tachograph could also register speed limit breaks and create warnings. Different rules of how to register and create warnings are possible, e.g. depending on how long time the speed limit break was and how many times within a certain time period. The registered data and warnings could be cryptographically stored and digitally signed. Data could be stored in the tachograph memory or a user module, e.g. a SMART card. The interfaces of the tachograph could also be used to present information of speed limits and breaks.
Speed limits of e.g. road could be automatically updated via e.g. a wireless interface. In the particular case of road speed limits, the ISA system could be used to get road speed limit values and updates.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects, advantages and effects as well as features of the present invention will be more readily understood from the following detailed description of exemplary embodiments of the invention when read together with the accompanying drawings, in which:

Fig. 1 schematically illustrates a digital tachograph DTG1 according to the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

While the invention covers various modifications and alternative constructions, embodiments of the invention are shown in the drawings and will hereinafter be described in detail. However it is to be understood that the specific description and drawings are not intended to limit the invention to the specific forms disclosed. On the contrary, it is intended that the scope of the claimed invention includes all modifications and alternative constructions thereof falling within the spirit and scope of the invention as expressed in the appended claims.
Fig 1 illustrates a tachograph according to the invention. The digital tachograph DTG1 comprises a control function TPROC suitable for handling functions in the tachograph. It could be a main processor or a distributed system. The control function could also comprise a real time clock and arithmetic unit suitable for calculation of e.g. driving times. The tachograph could also comprise different kind of memories. In this embodiment a tachograph memory TM is situated outside the control function. In this memory user related data could be stored, e.g. speed of vehicle, time of driving etc.
The tachograph is managed via a user interface, in this particular case comprising control knobs or buttons CONTR, a display DISPL and a printer PR. Those could be integrated in the tachograph or be situated externally via an interface.
The digital tachograph also comprises encryption means EM and data signing means DSM for securely handling of data. Driver related data such as driving time, speed of the vehicle, rest time for the driver etc can then be securely communicated and stored by e.g. the tachograph or a user module. The data signing means DSM provides a digital signature to a block of data. A digital signature is data appended to the data, or a cryptographic transformation of the data, to ensure the integrity and authenticity of the data.
The tachograph also comprises a motion sensor interface MSIF suitable for cryptographically secured data communication of information related to the motion of the vehicle. A motion sensor (MS) could be situated in the gearbox or the wheels of the vehicle and give signals about the speed of the vehicle. The tachograph can encrypt data from the motion sensor and transform the signals or pulses to the actual speed of the vehicle. There are also other possibilities to collect the speed of the vehicle and several motion sensors could be used. Examples are GPS, magnetic compass sensors or satellite signals.
The tachograph further comprises a user identification interface UIIF suitable for cryptographically secured data communication with a user module UM1. The tachograph also has means for identifying a user module connected to the user identification interface. The user module could be in form of a SMART card belonging to a special user or driver and could comprise a memory for storing user related data. An identification key is stored in the smart card and is used by the tachograph to identify the user module. In this way the user of the tachograph can be securely identified.
The tachograph further comprises an external data communication interface EDIF suitable for cryptographically secured data communication with an external memory EXM. This could be used for download data stored in the tachograph memory and/or on the user module.
The tachograph can register events and faults. An exceeding of the speed limit of the vehicle can be treated in that way.
Those data can be digitally signed and stored on the tachograph or on a user module.
In addition to handle the speed limit of the vehicle, the invention introduces the possibilities to take a second speed limit into consideration. The tachograph therefore comprises speed limit management means SLMM for management data related to speed limits. This speed management means could e.g. calculate and register speed limit breaks and display warnings.
This particular embodiment has a dedicated speed limit memory SLM for speed limit data. This memory could of course be integrated with other memories and be situated anywhere.
One example of a second speed limit is the road speed limit of a particular road or part of a road. The road speed limit is in this embodiment collected via at least one road speed limit interface RSLIF1, RSLIF2. The road speed limit data could of course be stored in a memory in the tachograph from the beginning but it is an advantage if the data could be easily upgraded and adapted to the roads where the vehicle is situated for the moment.
Several possibilities for getting road speed limit data are possible. Examples are navigator systems using e.g. GPS and road maps, download road speed limit data from a memory or the internet, beacons sending road speed limit data along the roads and optical recognition of speed signs. Road speed limit data could be received from different data bases comprising such information.
Intelligent speed adaption, ISA, is a system that could be connected to the tachograph to get accurate figures of the road speed limit on the road where the vehicle is situated.
The speed limit road data will automatically be updated when the vehicle is moving.
The road speed limit data is used by the tachograph for registration and to make warnings when a road speed limit is broken. Several solutions are for registration and/or warnings are possible. Different threshold values could be used, e.g. the amplitude of the speed limit break and the time frame within the speed was exceeding the speed limit. This means that even if the speed limit on a particular road is e.g. 90km/h, the registration of a break of a speed limit is only done if the speed limit is exceeding by a certain value, e.g. 2km/h, or 10%, or 2km/h for at least 1 minute, or 3 times within 10 minutes etc.
The system takes both the first speed limit, the speed limit of the vehicle, and the second speed limit, in this case the speed limit of the road into consideration. The registration and warning system registers and/or warns if one of the speed limits is broken. The registration and warnings could be digitally signed and stored in a memory, e.g. the memory in the user module, e.g. a driver card, or a memory in the tachograph. The system could be dynamic. Vehicle speed limit and road speed limit are only two examples. Several other speed limits values could be possible. Each of these examples could also be dynamic in themselves, e.g. dependant on weather, road conditions, driver, cargo features etc. They could automatically be upgraded. Examples of speed limits are:

Vehicle speed limit. Could be stored in the tachograph installed in the vehicle. This limit could be different if e.g. a trailer is attached to the vehicle.
Road speed limit. Collected from e.g. an ISA system.
Driver speed limit. A driver under training could have a lower speed limit than an experience driver. The speed limit could change depending on the time since the last rest of the driver. Driver speed limits could be stored on a driver card and communicated to the tachograph.
Cargo speed limit. Depending to the cargo the speed limit could have different values. The cargo could e.g. be fragile or explosive. The speed limit value could be manually stored in the tachograph. If the tachograph get information of the cargo it could automatically change this speed limit.

Speed limit breaks and warnings could be digitally signed by the tachograph and stored. This makes it possible for follow up by e.g. owner of the vehicle or legal authorities.
It will be obvious that the present invention may be varied in a plurality of ways. Such variations are not to be regarded as departure from the scope of the present invention as defined by the appended claims. All such variations as would be obvious for a person skilled in the art are intended to be included within the scope of the present invention as defined by the appended claims.

Claims

A digital tachograph suitable for being installed in a vehicle comprising:
- motion collection means (MS, MSIF) for collecting a vehicle speed value, said vehicle speed value is the speed of the vehicle

- vehicle speed limit collection means for collecting a first speed limit value, said speed limit value is the vehicle speed limit,
characterized in that it comprises:
- a second speed limit collection means (RSLIF1, RSLIF2) for collecting at least a second speed limit value, e.g. road speed limit, driver speed limit or cargo speed limit.

- speed limit management means (SLMM) for register a speed limit break if the speed of the vehicle exceeds one of the speed limit values
A digital tachograph according to the preceding claim where the speed limit management means comprising means for create a speed limit warning if a speed limit break is registered
A digital tachograph according to any of the preceding claims where a speed limit break is depending on how much the speed of the vehicle is exceeding a speed limit value
A digital tachograph according to any of the preceding claims where the speed limit break is depending on the time period, and/or the number of times within a certain time period, a speed exceeds a certain speed limit value
A digital tachograph according to any of the preceding claims comprising means for cryptographically store speed limit brakes and/or speed limit warnings
A digital tachograph according to any of the preceding claims comprising digital signing means (DSM) for digital signing of data comprising information on speed limit brakes and/or speed limit warnings
A digital tachograph according to any of the preceding claims comprises means for display speed values and/or speed limit warnings using the tachograph interfaces, e.g. display or printer.
A digital tachograph according to any of the preceding claims where the second speed limit value is automatically downloaded and stored into the tachograph via a wireless interface.
A digital tachograph according to any of the preceding claims comprising means for store information of speed limit brakes and/or warnings on a tachograph memory and/or on a user module, e.g. a SMART card, connected to the tachograph
A digital tachograph according to any of the preceding claims where the second speed limit value is a road speed limit value for a specific road or part of a road.
A digital tachograph according to claim 10 where the road speed limit is collected via the system for Intelligent Speed Adaptation (ISA).
A method in a tachograph according to any of the preceding claims comprising the steps of:
- receiving a road speed limit value

- receiving the speed of the vehicle

- calculate the difference between the road speed limit value and the speed of the vehicle