LOCKING DEVICE FOR VEHICLES

Technical field

The present invention relates to a vehicle locking system for a motor vehicle and to a motor vehicle with such a vehicle locking system. More specifically, the invention relates to vehicle locking systems intended to prevent drivers from driving motor vehicles while under the influence of alcohol.

State of the art A problem to which society is paying increasing attention is the driving of motor vehicles by drivers under the influence of alcohol, who can represent a major danger to the general public. Various different measures can be adopted for preventing drivers under the influence of alcohol from driving motor vehicles. One possible measure is to equip motor vehicles with a vehicle locking system which prevents a driver under the influence of alcohol from starting the vehicle. Such vehicle locking systems are commonly known as "alcolocks". There is ongoing discussion in many countries about introducing legal requirements to the effect that for new motor vehicles to be saleable they must be equipped with alcolocks.

Alcolocks usually comprise an alcohol sensor, a circuit-breaker switchable between a first position in which the vehicle cannot be started and a second position in which the vehicle can be started, and a control unit connected to the alcohol sensor and the circuit-breaker. The control unit is adapted to switching the circuit-breaker between the first and second positions depending on whether the alcohol sensor detects alcohol or not. To be able to start a vehicle equipped with an alcolock, the driver has to do a breath test. If the driver's breath contains alcohol, this is detected by the alcohol sensor, which sends a signal to that effect to the control unit. The control unit then places the circuit-breaker in the first position so that the vehicle cannot be started. If the driver's breath does not contain alcohol, the alcohol sensor sends a signal to that effect to the control unit, which then places the circuit-breaker in the second position in which the vehicle can be started. The alcohol sensor is usually fitted permanently in the vehicle together with the control unit and the circuit-breaker, but some vehicles are

equipped with wireless alcohol sensors which communicate wirelessly with a control unit which is permanently fitted in the vehicle. An advantage of wireless alcohol sensors is that they can be stored outside the vehicle while it is parked, so that they are not subject to the temperature variations which occur in the interior of a motor vehicle, which may range from -3O ⁰ C or below on cold winter nights to +5O ⁰ C or above on sunny summer days. These temperature variations impose severe requirements for alcohol sensors fitted permanently in motor vehicles. It is therefore advantageous to use a wireless alcohol sensor which can be stored in a heated room in a building while the vehicle is parked. In the case of a wireless alcohol sensor, the sensor comprises a transmitter and the control unit in the vehicle is connected to or comprises a receiver for receiving signals from the transmitter in the sensor.

Alcolocks in motor vehicles can be arranged to only respond to signals from a specific alcohol sensor. This is achieved by the sensor indicating its identity in each signal which conveys information about the results of an alcohol measurement. This makes it difficult to manipulate an alcolock with a view to being able to start a vehicle without any prior alcohol measurement.

US patent 6,886,653 describes a breath alcohol detection system fitted to a motor vehicle and adapted to identifying a driver who breathes into the detection system. The vehicle cannot be started until the driver has done a breath alcohol test and has been positively identified.

Haulage, bus and taxi companies are examples of organisations in which a large number of drivers drive a large number of motor vehicles. It is of course desirable for such organisations to equip their vehicles with alcolocks and particularly with wireless alcolocks, but a problem in this context is that the risk of alcohol sensors going astray increases with an increasing number of drivers. Another problem is that it is difficult to keep track of which alcohol sensor belongs to which vehicle. It would also be desirable to know which drivers use each vehicle.

Summary of the invention

An object of the present invention is to propose a locking device for a motor vehicle and a motor vehicle with such a locking device which at least partly solve the problems of the state of the art.

Another object of the present invention is to propose a locking device for a motor vehicle and a motor vehicle with such a locking device whereby it is possible to determine beforehand which vehicles each driver has permission to drive.

A further object of the present invention is to propose a locking device for a motor vehicle and a motor vehicle with such a locking device which make it possible to register drivers when they try to start the vehicle.

At least one of these objects is achieved with a locking device for a motor vehicle according to the independent claim.

Further advantages of the invention are afforded by features in the dependent claims.

A vehicle locking system according to the invention is intended for a motor vehicle. The vehicle locking system comprises a locking device which is settable in a first position in which the vehicle cannot be started and a second position in which the vehicle can be started, a control unit comprising a receiver for receiving a message and adapted to controlling the locking device on the basis of the message, and an alcohol detector which comprises an alcohol sensor adapted to measuring an alcohol content and a transmitter. The transmitter is adapted to sending to the control unit a message containing information about the alcohol content. The vehicle locking system is adapted to determining whether the measured alcohol content is below a predetermined alcohol level, and the control unit is adapted to only placing the locking device in the second position if the measured alcohol content is below the predetermined alcohol level. The vehicle locking system is characterised in that the alcohol detector has a unique identity number, that the transmitter is adapted to including the identity number of the alcohol detector in the message sent, that the control unit has a list of at least two approved identity numbers, and that the control

unit is adapted to comparing the identity number received with the list of approved identity numbers and to only placing the locking device in the second position if the identity number is found on the list of approved identity numbers.

A vehicle locking system according to the invention allows access to any of a large number of vehicles by any of a large number of the drivers. The various drivers can have access to their respective choice of vehicle. The drivers may each be equipped with their own alcohol detector. Each driver having an alcohol detector of his/her own affords the possibility of automatically registering drivers who have too high an alcohol content when they try to start a motor vehicle.

The alcohol detector may comprise means for receiving the driver's breath and be adapted to measuring the alcohol content of the breath. Measuring the alcohol content of the breath is a relatively easy and uncomplicated way of measuring a degree of intoxication, but the alcohol detector may be adapted to measuring the driver's alcohol content in some other way, e.g. it may be adapted to measuring the driver's alcohol content by measurement on the driver's skin.

The alcohol detector may be adapted to determining whether the measured alcohol content of the breath is below the predetermined alcohol level and the information about the alcohol content in the message will comprise information about whether the measured alcohol content is below the predetermined level. Alternatively, the control device may be adapted to determining whether the measured alcohol content of the breath is below the predetermined alcohol level and the information about the alcohol content in the message will comprise the measured alcohol content. Each of these two alternatives has its advantages. An advantage of the first alternative is that it makes it possible to have different predetermined alcohol levels for different drivers.

The control unit may comprise a memory in which the control unit is adapted to storing the identity number received if the measured alcohol content is above the predetermined alcohol level. Storing the identity number received if the measured alcohol content is above the predetermined alcohol level makes it possible for the

employer to do follow-up about drivers who try to start one of the employer's vehicles while intoxicated.

The control unit may be adapted to storing the identity number received irrespective of the measured alcohol content, thereby providing the employer with information about who drives each vehicle. The identity number may be stored together with information about the time when drivers try to start a vehicle and information about the alcohol content in their blood when they do so.

The transmitter may be adapted to sending a message wirelessly, which makes it easy for drivers to take the alcohol detector with them to and from the vehicle.

The power of the transmitter and the sensitivity of the receiver can be matched so that the range of the transmitter is not more than 5 metres and, with advantage, less than 2 metres. Matching the transmitter power and the receiver sensitivity in this way minimises the problem of a driver's being able to place the locking device in the second position in more than one vehicle at a time.

The control unit and the receiver may be integrated in a single unit or alternatively the control unit may be connected to the receiver by a communication link, in which case the receiver may also have another function, e.g. serving as a receiver for a remote- controlled central locking system.

The alcohol detector may be adapted to sending its message upon request from a user, in which case it is equipped with a memory in which the result of an alcohol measurement can be stored. Such a function makes it possible for the driver to perform the alcohol measurement elsewhere than in the vehicle and thereby avoid passengers being aware that an alcohol measurement has taken place.

According to another aspect of the present invention, a vehicle is provided with a vehicle locking system according to any one of the claims.

Preferred embodiments of the invention are described below with reference to the attached drawings.

Brief description of the drawings

Fig. 1 depicts a motor vehicle with a vehicle locking system according to an embodiment of the present invention.

Fig. 2 depicts schematically a vehicle locking system according to an embodiment of the invention.

Fig. 3 is a flowchart illustrating the function of a vehicle locking system according to an embodiment of the invention.

Description of preferred embodiments of the invention

In the following description of preferred embodiments of the invention, the same reference notations are used for similar items in the various drawings.

Fig. 1 depicts a motor vehicle with a vehicle locking system according to an embodiment of the present invention. Fig. 1 depicts a vehicle 1 according to an embodiment of the present invention. The vehicle 1 comprises a first powered wheel 3 and a second powered wheel 4 which are adapted to being driven by an engine 2. The vehicle 1 also comprises a locking device 5 which is settable in a first position in which the vehicle cannot be started and a second position in which the vehicle can be started. More specifically, the engine 2 of the vehicle cannot be started when the locking device 5 is in the first position but can be started when the locking device 5 is in the second position. The vehicle 1 also comprises a control unit 6 which has a receiver 7 for receiving a message and which is adapted to controlling the locking device 5 on the basis of the message. The vehicle 1 also comprises a driving cab 8, the interior of which is provided with an alcohol detector 9 comprising an alcohol sensor (Fig. 2) which is adapted to measuring a driver's alcohol content and which comprises

a transmitter 10. The transmitter 10 is adapted to sending to the control unit 6 a message containing information about the alcohol content, and the vehicle locking system is adapted to determining whether the measured alcohol content is below a predetermined alcohol level. The control unit 6 is adapted to only placing the locking device 5 in the second position if the measured alcohol content is below the predetermined alcohol level. The driving cab is also provided with signal means comprising a lamp and/or a loudspeaker (not depicted) for signalling that an alcohol measurement is required.

A driver about to start the vehicle depicted in Fig. 1 enters the driving cab 8 and inserts a key in an ignition lock. The signal means will then emit an acoustic and/or a light signal to the effect that an alcohol measurement is required. The driver then uses the alcohol detector 9 to perform an alcohol measurement, e.g. by blowing into the alcohol detector 9. The alcohol detector 9 determines, on the basis of the measurement and by means of the alcohol sensor, the alcohol content of the driver's blood. The alcohol detector 9 compares the alcohol content determined with a predetermined alcohol level stored in the alcohol detector 9. The transmitter 10 of the alcohol detector 9 sends to the control unit a message comprising the identity number of the alcohol detector and information about whether the measured alcohol content is above or below the predetermined alcohol level in the alcohol detector 9. If the alcohol content is below the predetermined alcohol level, the message sent is, for example, a one, and if the alcohol content is above the predetermined alcohol level a zero is sent. The receiver 7 of the control unit 6 receives the message from the alcohol detector 9, and the control unit 6 compares the identity number received with a list of identity numbers which is stored in the control unit 6. If the identity number received is found on the list and the measured alcohol content is below the predetermined alcohol level, the control unit 6 acts upon the locking device 5 so that the locking device 5 is placed in the second position, making it possible for the vehicle to be started.

As an alternative to the mode of operation described, the alcohol detector 9 may be adapted to sending the measured alcohol content together with the identity number of the alcohol detector to the receiver 7 of the control unit 6. The control unit compares

the measured alcohol content with a limit value and compares the identity number received with a list of identity numbers which is stored in the control unit 6. If the identity number received is found on the list and the measured alcohol content is below the limit value, the control unit 6 acts upon the locking device 5 so that the locking device 5 is placed in the second position, making it possible for the motor vehicle to be started. If the measured alcohol content is above the limit value, the control unit 6 stores the identity number in a list of attempts by intoxicated drivers to start the vehicle 1.

Fig. 2 depicts schematically a locking system according to an embodiment of the invention. The vehicle locking system 100 comprises a locking device 5 which is settable in a first position in which the vehicle cannot be started and a second position in which the vehicle can be started. The vehicle locking system 100 further comprises a control unit 6 with a receiver 7, and a locking device 5. In the embodiment depicted, the control unit is connected to the receiver via a communication bus 11 but it is also possible for the control unit to be connected to the receiver in some other way or for the control unit 6 and the receiver 7 to be integrated in a single unit. The alcohol detector 9 in the embodiment depicted is equipped with a wireless transmitter 10. Alternatively, the transmitter may be connected to the receiver 7 of the control unit 6 by a cable 12 represented in the drawing by a broken line. The alcohol detector further comprises means for receiving the driver's breath in the form of a blowing tube 13 and an alcohol sensor 14 which is adapted to measuring the alcohol content of the air which passes through the blowing tube 13. The alcohol detector also comprises a temperature sensor 15 adapted to measuring the temperature of the air which passes through the blowing tube 13, and a display 19 which presents the result of the measurement. The alcohol detector may also have a memory 16 for storing the result of an alcohol measurement, a first push-button 17 for initiating an alcohol measurement and a second push-button 18 for transmitting the result of an alcohol measurement. The control unit 6 has a memory 20 in which the identity number can be stored when the measured alcohol content is above the predetermined alcohol level.

The power of the transmitter and the sensitivity of the receiver can be matched so that the range of the transmitter is not more than 5 metres. The receiver may also be adapted to serving as a receiver for a remote-controlled central locking system of the vehicle.

Using the alcohol detector 9 involves the driver blowing into the blowing tube 13 of the alcohol detector 9 after having pressed the first push-button 17 to initiate the alcohol measurement. The alcohol sensor 14 registers the alcohol concentration in the air which passes through the blowing tube 13 while at the same time the temperature sensor 15 measures the temperature of the breath. If the temperature of the breath exceeds a predetermined level, the alcohol detector 9 determines the alcohol content of the blood and compares it with a predetermined alcohol level as described above. The message sent from the transmitter 10 of the alcohol detector 9 is received by the receiver 7. The receiver 7 identifies that the message received comes from an alcohol detector and passes the message on via the communication bus 11 for reception by the control unit 6. The control unit then processes the information in the message in the same way as described above. If the measured alcohol content exceeds the predetermined level, the identity number is stored in the memory 20 of the control unit.

In cases where the alcohol detector 9 has a memory 16 and a second push-button 18 for sending a message, the driver may perform the alcohol measurement before sitting in the vehicle 1. When the vehicle signals that an alcohol measurement should commence, the driver can send the result of the previously made alcohol measurement to the control unit by pressing the second push-button 18.

Fig. 3 is a flowchart illustrating the function of a vehicle locking system according to the invention. At a first step 301, a driver tries to start the vehicle 1, whereupon the control unit 6 initiates signalling to the effect that alcohol measurement is required. At a second step 302, the driver blows into the blowing tube 13 of the alcohol detector 9 and the alcohol content is measured. At a third step 303, the alcohol detector 9 compares the measured alcohol content with a limit value. At a fourth step 304 the alcohol detector 9 sends the identity number (ID) and the result of the comparison in a

message to the control unit 6. At a fifth step 305, the control unit 6 reads the information in the message and compares the identity number with a list of identity numbers. If the identity number is not found on the list, the control unit goes to a sixth step 306 at which the locking device 5 is kept in the first position. If the identity number is found on the list, the control unit 6 goes to a seventh step 307 at which the control unit 6 decides whether the result of the alcohol measurement is below the limit value in the form of a predetermined alcohol level. If the result is not below the limit value, the control unit goes to an eighth step 308 at which the identity number is stored in the memory 20 of the control unit 6 and the locking device 5 is kept in the first position. If the result is below the limit value, the control unit goes to a ninth step 309 at which the locking device is placed in the second position in which the vehicle 1 can be started.

The embodiments described can be modified in many ways without departing from the spirit and scope of the invention, which is only limited by the claims.

It is for example possible to use sensors other than those described, e.g. it is possible to exclude the temperature sensor 15 in an alcohol detector 9 according to the invention.

It is possible to adapt the alcohol detector 9 to measuring a driver's alcohol content in some other way than by measuring the alcohol concentration in the breath, e.g. the alcohol content may be measured through the driver's skin.

The alcohol content which is compared with the limit value may either be a measured alcohol content, e.g. the alcohol concentration in the breath, or an alcohol content determined by the measured alcohol content, e.g. the actual alcohol content of the driver's blood.