POWER PLANT STARTING DEVICE AND POWER PLANT STARTING METHOD

BACKGROUND OF THE INVENTION

1. Field of the Invention

[0001] The invention relates to a device and a method for starting a power plant for driving a vehicle.

2. Description of the Related Art

[0002] The prevention of drinking and driving is a societal demand, and devices for preventing drinking and driving have conventionally been devised. An automobile key endowed with a function of preventing drinking and driving is disclosed in Japanese Patent Application Publication No. 2004-169524 (JP-A-2004-169524). A key holder body of this key endowed with the function of preventing drinking and driving is extractably/retractably provided with a mechanical key, and has an alcohol detector incoφorated therein. When the concentration of alcohol in the breath of a driver is lower than a preset reference value, a lock mechanism is released to enable the mechanical key. On the other hand, when the concentration of alcohol is higher than the reference value, the lock mechanism is not released, so the mechanical key is disabled. [0003] After the mechanical key has been enabled, the driver inserts the mechanical key into a door key cylinder, operates the mechanical key to an unlock side to open doors, then inserts the mechanical key into an ignition key cylinder, and operates an ignition switch to start an engine, as in the case of a normal automobile key. [0004] In starting the engine using the aforementioned key endowed with the function of preventing drinking and driving, alcohol detection needs to be carried out in addition to a conventional starting action. In other words, with a view to starting the engine, actions made up of at least two stages (the action of carrying out alcohol detection and the action of inserting the mechanical key into the ignition key cylinder and operating the

ignition switch) are required, which may be bothersome to the driver.

SUMMARY OF THE INVENTION

[0005] The invention provides a power plant starting device and a power plant starting method that make it possible to prevent drinking and driving without increasing the bothersomeness in starting a power plant.

[0006] A power plant starting device according to an aspect of the invention is characterized by including an alcohol detection unit that detects a concentration of alcohol in a driver, and a start unit that starts a power plant for driving a vehicle in interlocking relationship with a result that the concentration of alcohol detected by the alcohol detection unit is lower than a predetermined reference value. [0007] In the power plant starting device according to the aspect of the invention, the concentration of alcohol in the breath or blood of the driver is detected, and the power plant is started in interlocking relationship with a result that the detected concentration of alcohol is lower than the predetermined reference value. In this manner, alcohol detection and the starting of the power plant are interlocked with each other. Therefore, the driver, when sober, can start the power plant, for example, an engine or the like simply by undergoing alcohol detection, namely, without operating the ignition switch. [0008] The alcohol detection unit may be provided in the vehicle. [0009] Meanwhile, the power plant starting device according to the aspect of the invention may further include a transmitter-type electronic key that automatically unlocks doors of the vehicle from outside the vehicle, and may be designed such that the aforementioned alcohol detection unit is incorporated in the electronic key, that the electronic key transmits a signal for unlocking the doors of the vehicle without taking the concentration of alcohol detected by the alcohol detection unit into account and transmits the concentration of alcohol detected by the alcohol detection unit to the start unit, and that the start unit starts the power plant in interlocking relationship with a result that the detected concentration of alcohol, which is received from the electronic key, is lower than the predetermined reference value.

[0010] In this case, the alcohol detection unit is incorporated in the transmitter-type electronic key, and the start unit starts the power plant in interlocking relationship with a result of alcohol detection received from the electronic key. Therefore, the driver, when sober, can start the power plant, for example, an engine or the like simply by undergoing alcohol detection outside the vehicle. The doors of the vehicle are unlocked regardless of the detected concentration of alcohol. Therefore, the driver, even when drunk, can be prevented from becoming unable to get into the vehicle.

[0011] In another aspect of the invention, a power plant starting method includes detecting a concentration of alcohol in a driver, and starting a power plant for driving a vehicle in interlocking relationship with a result that the detected concentration of alcohol is lower than a predetermined reference value.

[0012] According to each aspect of the invention, the power plant is started in interlocking relationship with a result that the detected concentration of alcohol is lower than the predetermined reference value. Therefore, drinking and driving can be prevented without increasing the bothersomeness in starting the power plant.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The foregoing and further features and advantages of the invention will become apparent from the following description of preferred embodiments with reference to the accompanying drawings, wherein like numerals are used to represent like elements and wherein:

FIG 1 is a block diagram showing the configuration of a power plant starting device according to a first embodiment of the invention;

FIG 2 is a flowchart showing the processing procedure of an engine start processing performed by the power plant starting device according to the first embodiment of the invention;

FIG 3 is a block diagram showing the configuration of a power plant starting device according to a second embodiment of the invention;

FIG 4 is a flowchart showing the processing procedure of an engine start processing

performed by the power plant starting device according to the second embodiment of the invention;

FIG 5 is a block diagram showing the configuration of a power plant starting device according to a third embodiment of the invention; and

FIG 6 is a flowchart showing the processing procedure of an engine start processing performed by the power plant starting device according to the third embodiment of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

[0014] The embodiments of the invention will be described hereinafter in detail with reference to the drawings. In the drawings, like numerals or symbols are used to represent like or corresponding elements. First Embodiment

[0015] First of all, the configuration of a power plant starting device 1 according to the first embodiment of the invention will be described using FIG 1. FIG. 1 is a block diagram showing the configuration of the power plant starting device 1. [0016] A vehicle mounted with the power plant starting device 1 is equipped with an engine 10 as a power plant for driving the vehicle. The engine 10 of this embodiment of the invention is an existing port injection-type gasoline engine. However, the engine 10 may also be a cylinder injection-type gasoline engine, a diesel engine, or the like. The invention is also applicable to vehicles other than gasoline engine vehicles, namely, hybrid vehicles employing a hybrid system composed of an engine and an electric motor as a power plant, electric vehicles employing an electric motor as a power plant, and the like.

[0017] In the engine 10, a mixture of air sucked in from an intake pipe and fuel injected from an injector is ignited and burned in each cylinder to generate a driving force. Exhaust gas produced after the burning of the mixture is discharged through an exhaust pipe. The driving force output from the engine 10 is transmitted to driving wheels via a transmission, a differential, a drive shaft, and the like.

[0018] The engine 10 is mounted with a starter motor 11 for starting the engine 10. The starter motor 11 is driven by electric power supplied from a battery 12 via a starter relay 13. A pinion gear is mounted on a drive shaft of the starter motor 11. This pinion gear drives a ring gear of the engine 10, thereby cranking and starting the engine 10. The pinion gear and the ring gear are decoupled from each other as soon as the engine 10 is started. A starter used to start the engine 10 is not limited to an electric starter motor. A hydraulic starter or the like can be employed as well. [0019] The starter relay 13 permits or shuts off (turns on/off) the supply of electric power to the starter motor 11. The starter relay 13 is connected to an electronic control unit (hereinafter referred to as the "ECU") 20, and is turned on/off on the basis of a start signal STAR from the ECU 20.

[0020] The ECU 20 has therein a microprocessor for making calculations, a ROM in which programs for causing this microprocessor to perform various processings and the like are stored, a RAM in which various pieces of data such as calculation results and the like are stored, a backup RAM whose storage contents are held because of using the battery 12, and the like.

[0021] Various sensors such as a crank position sensor for detecting a crank position, an airflow meter for detecting an amount of intake air, an accelerator opening degree sensor for detecting an opening degree of an accelerator pedal, a coolant temperature sensor for detecting a temperature of coolant, and the like are connected to the ECU 20. [0022] The ECU 20 is equipped with an injector driver for driving the injector, an output circuit for outputting an ignition signal, a motor driver for driving an electric motor for opening/closing an electronically controlled throttle valve, and the like. [0023] The ECU 20 calculates control values such as a fuel injection amount, an ignition timing, and the like on the basis of output values from the aforementioned various sensors, and drives the injector, an ignition plug, and the like on the basis of the calculated control values to control the operation of the engine 10. [0024] An alcohol detector 21 is connected to the ECU 20. A result detected by the alcohol detector 21 is input to the ECU 20. When the detected result is lower than a

predetermined reference value, the ECU 20 determines that a driver is sober, outputs the start signal STAR for turning the starter relay 13 on in interlocking relationship with the inputting of the detected result, and starts the supply of fuel and ignition to start the engine 10. That is, the ECU 20, the starter motor 11, and the starter relay 13 function as a start unit.

[0025] In making a determination on the state of drinking in accordance with the concentration of alcohol in breath, the aforementioned predetermined reference value is set between 0 (mg/1) and 0.15 (mg/1). This reference value, which is preferably close to zero, is set in consideration of the detection accuracy of the detector and the like. [0026] The alcohol detector 21, which detects the concentration of alcohol contained in the breath or blood of the driver, is mounted on, for example, a steering wheel, a seat belt, or the like of the vehicle.

[0027] As long as the alcohol detector 21 can detect the concentration of alcohol contained in the breath or blood of the driver, the detection method thereof is not limited in particular. For example, a handy blow-type, stationary blow-type, or remote suction-type alcohol detector employing a semiconductor sensor, a fuel cell sensor, an infrared ray sensor, or a chemical substance sensor, a contact-type alcohol detector employing an optical contact sensor, or the like can be used.

[0028] Making use of a characteristic that the amount of electrons flowing through a semiconductor changes due to the absorption of electrons by alcohol, the semiconductor sensor detects a concentration of alcohol from a change in the value of electric resistance resulting from a change in the amount of electrons. Making use of a characteristic of a fuel cell that can create electrons from alcohol, the fuel cell sensor detects a concentration of alcohol from an electric current value corresponding to the number of created electrons. Making use of a characteristic that infrared rays are absorbed by alcohol, the infrared ray sensor converts infrared rays absorbed by alcohol into an electric signal by means of a photodetector, and analyzes the electric signal to detect a concentration of alcohol. Making use of a characteristic that a chemical substance changes in color through a chemical reaction with alcohol, the chemical substance sensor detects a concentration of

alcohol. Making use of a fact that there is a correlation between the concentration of alcohol in blood and the flow of venous blood, the optical contact sensor detects a concentration of alcohol in blood on the basis of the flow of venous blood at a fingertip detected by the sensor.

[0029] As described above, the alcohol detector 21 is connected to the ECU 20, and outputs a detection result of the concentration of alcohol, namely, data corresponding to the concentration of alcohol to the ECU 20. It is also appropriate to adopt a configuration in which the alcohol detector 21 itself determines whether or not the detected concentration of alcohol is lower than the reference value and outputs a determination result thereof to the ECU 20 instead of causing the ECU 20 to determine whether or not the concentration of alcohol is lower than the reference value. [0030] Next, the action of the power plant starting device 1 will be described with reference to FIG 2. FIG. 2 is a flowchart showing the processing procedure of an engine start processing performed by the power plant starting device 1.

[0031] In step SlOO, the driver blows breath onto the alcohol detector 21, so the concentration of alcohol in the breath is detected. The concentration of alcohol detected by the alcohol detector 21 is read by the ECU 20.

[0032] Then in step S102, it is determined whether or not the detected concentration of alcohol is lower than a reference value (e.g., 0.1 mg/1). When the concentration of alcohol is lower than the reference value, it is determined that the driver is sober, so the engine 10 is automatically started in interlocking relationship with the result of detection (step S 104). More specifically, the start signal STAR is automatically output from the ECU 20 to the starter relay 13 in interlocking relationship with the result of detection, the starter relay 13 is turned on, and the starter motor 11 is supplied with electric power. Then, the starter motor 11 is driven to crank the engine 10, and the supply of fuel and ignition are started to start the engine 10. When it is determined on the basis of an engine rotational speed of the engine 10 or the like that the engine 10 has been started, the starter relay 13 is turned off. [0033] On the other hand, when the detected concentration of alcohol is equal to or

higher than the reference value, it is determined that the driver is drunk, so the present processing is exited without starting the engine 10.

[0034] According to this embodiment of the invention, the concentration of alcohol in the breath or blood of the driver is detected, and the engine 10 is started in interlocking relationship with a detection result thereof when the detection result is lower than the predetermined reference value. In this manner, alcohol detection and the starting of the engine 10 are interlocked with each other. Therefore, the driver, when sober, can start the engine 10 simply by undergoing alcohol detection, namely, without operating the ignition switch. On the other hand, the driver, when drunk, is prohibited from starting the engine 10. Therefore, drinking and driving can be prevented without increasing the bothersomeness in starting the engine 10.

[0035] According to this embodiment of the invention, a check on drinking directly leads to the action of starting the engine. Therefore, through repetition of this action, the driver can be made aware that the method of starting the engine is tantamount to a check on drinking. Second Embodiment

[0036] In the foregoing first embodiment of the invention, a vehicle adopting a door lock system that allows doors to be unlocked (or locked) by inserting a mechanical key into a key cylinder mounted in any one of the doors and operating the mechanical key to an unlock side (or a lock side) is envisaged as a vehicle mounted with the power plant starting device according to the invention. The power plant starting device according to the invention is also applicable to vehicles adopting a so-called keyless entry system that allows doors to be unlocked (or locked) remotely without operating a key. Thus, description of a case where the invention is applied to a vehicle adopting the keyless entry system (the second embodiment of the invention) will be given subsequently. [0037] First of all, the configuration of a power plant starting device 2 according to the second embodiment of the invention will be described using FIG 3. FIG 3 is a block diagram showing the configuration of the power plant starting device 2 according to the second embodiment of the invention. In FIG 3, components identical or equivalent to

those of the power plant starting device 1 are denoted by the same reference numerals or symbols respectively.

[0038] The power plant starting device 2 is further equipped with a keyless entry system in addition to the components of the power plant starting device 1. That is, the power plant starting device 2 is equipped with a transmitter-type electronic key 30, a vehicle interior receiver 31, and a door lock unit 32. The transmitter-type electronic key 30 transmits an own vehicle identification code and a function code through faint radio waves to automatically unlock (or lock) doors of a vehicle from outside the vehicle. The vehicle interior receiver 31 receives the own vehicle identification code and the function code, carries out a collation of the identification code and a determination on the function code, and outputs the identification code and the function code as code data upon recognizing that the identification code coincides with an own vehicle code and that the function code indicates "unlock (or lock)". The door lock unit 32 receives the code data, and turns an unlock relay (or a lock relay) on to unlock (or lock) all the doors. [0039] The vehicle interior receiver 31 is also connected to an ECU 2OB. Upon recognizing that the identification code coincides with the own vehicle code, the vehicle interior receiver 31 outputs the identification code to the ECU 20B as code data. [0040] When the detection result obtained by the alcohol detector 21 is lower than a predetermined reference value and the identification code coincides with the own vehicle code, the ECU 2OB determines that the driver is sober and that a key has been authenticated, outputs the start signal STAR for turning the starter relay 13 on in interlocking relationship with the inputting of the result of alcohol detection, and starts the supply of fuel and ignition to start the engine 10. That is, the ECU 2OB, the starter motor 11, and the starter relay 13 also function as the start unit. The second embodiment of the invention is identical or similar to the foregoing first embodiment of the invention in other configurational details, so description thereof will be omitted below.

[0041] Next, the action of the power plant starting device 2 will be described with reference to FIG 4. FIG. 4 is a flowchart showing the processing procedure of an engine

start processing performed by the power plant starting device 2.

[0042] In step S200, authentication of the key is carried out. That is, authentication of the key is carried out depending on whether or not the identification code transmitted from the transmitter-type electronic key 30 coincides with the own vehicle code. A result of authentication of the key is read by the ECU 2OB.

[0043] Then in step S202, the driver blows breath onto the alcohol detector 21, so the concentration of alcohol in the breath is detected. The concentration of alcohol detected by the alcohol detector 21 is read by the ECU 2OB.

[0044] Then in step S204, it is determined whether or not the detected concentration of alcohol is lower than a reference value (e.g., 0.1 mg/1) and whether or not the identification code coincides with the own vehicle code. When the concentration of alcohol is lower than the reference value and the identification code coincides with the own vehicle code, it is determined that the driver is sober and that the key has been authenticated, so the engine 10 is automatically started in interlocking relationship with the result of alcohol detection (step S206). More specifically, the start signal STAR is automatically output from the ECU 2OB to the starter relay 13 in interlocking relationship with the detection result, so the starter relay 13 is turned on and the starter motor 11 is supplied with electric power. Then, the starter motor 11 is driven to crank the engine 10, and the supply of fuel and ignition are started to start the engine 10. When it is determined on the basis of an engine rotational speed of the engine 10 or the like that the engine 10 has been started, the starter relay 13 is turned off.

[0045] On the other hand, when the detected concentration of alcohol is equal to or higher than the reference value or when the identification code does not coincide with the own vehicle code, it is determined that the driver is drunk or that the key has not been authenticated, so the present processing is exited without starting the engine 10. [0046] According to this embodiment of the invention as well, as in the case of the foregoing first embodiment of the invention, the driver, when sober, can start the engine 10 simply by undergoing alcohol detection, namely, without operating the ignition switch. On the other hand, the driver, when drunk, is prohibited from starting the engine 10.

Therefore, drinking and driving can be prevented without increasing the bothersomeness in starting the engine 10. Third Embodiment

[0047] In the foregoing second embodiment of the invention, the case where the power plant starting device according to the invention is applied to the vehicle adopting the keyless entry system has been described. The power plant starting device according to the invention is also applicable to vehicles adopting a so-called key free system that allows doors to be unlocked (or locked) and an engine to be started without performing an operation of inserting a key. Thus, description of a case where the invention is applied to a vehicle adopting the key free system (the third embodiment of the invention) will be given subsequently.

[0048] First of all, the configuration of a power plant starting device 3 according to the third embodiment of the invention will be described using FIG 5. FIG. 5 is a block diagram showing the configuration of the power plant starting device 3. In FIG 5, components identical or equivalent to those of the power plant starting device 2 are denoted by the same reference numerals or symbols respectively.

[0049] This embodiment of the invention is different from the foregoing second embodiment of the invention in that an alcohol detector 21C is incorporated in a transmitter-type electronic key 30C and that the transmitter-type electronic key 30C transmits a result of alcohol detection as well as an own vehicle identification code and a function code through faint radio waves. This embodiment of the invention is also different from the foregoing second embodiment of the invention in that, upon recognizing that the identification code coincides with an own vehicle code, a vehicle interior receiver 31C outputs this result of key authentication and the result of alcohol detection to an ECU 2OC as code data.

[0050] In addition, when the result of alcohol detection input from the vehicle interior receiver 31C is lower than a predetermined reference value and the identification code coincides with the own vehicle code, the ECU 20C determines that the driver is sober and that the key has been authenticated, and starts the engine 10 in interlocking relationship

with the inputting of the result of alcohol detection. That is, the ECU 2OC, the starter motor 11, and the starter relay 13 also function as a start unit. This embodiment of the invention is identical or similar to the foregoing second embodiment of the invention in other configurational details, so description thereof will be omitted below.

[0051] Next, the action of the power plant starting device 3 will be described with reference to FIG 6. FIG. 6 is a flowchart showing the processing procedure of an engine start processing performed by the power plant starting device 3.

[0052] In step S300, the driver blows breath onto the alcohol detector 21C incorporated in the transmitter-type electronic key 30C outside the vehicle, so the concentration of alcohol in the breath is detected.

[0053] Then in step S302, the own vehicle identification code, the function code, and the concentration of alcohol detected in step S300 are transmitted from the transmitter-type electronic key 3OC.

[0054] Then, in step S304, the own vehicle identification code, the function code, and the result of alcohol detection, which are transmitted from the transmitter-type electronic key 3OC, are received by the vehicle interior receiver 31C.

[0055] Subsequently, in step S306, it is determined whether or not the identification code transmitted from the transmitter-type electronic key 30C coincides with the own vehicle code. When the identification code coincides with the own vehicle code, a transition of the processing to step S308 is made. On the other hand, when the identification code does not coincide with the own vehicle code, the present processing is temporarily exited without unlocking the doors or starting the engine 10.

[0056] When the identification code coincides with the own vehicle code (when the key has been authenticated), the doors of the vehicle are unlocked in step S308. That is, the doors of the vehicle are unlocked in accordance with a result of key authentication, regardless of a result of alcohol detection.

[0057] Then in step S310, it is determined whether or not the detected concentration of alcohol is lower than a reference value (e.g., 0.1 mg/1). When the concentration of alcohol is lower than the reference value, it is determined that the driver is sober, so the

engine 10 is automatically started in interlocking relationship with the result of alcohol detection (step S312).

[0058] On the other hand, when the detected concentration of alcohol is equal to or higher than the reference value, it is determined that the driver is drunk, so the present processing is exited without starting the engine 10.

[0059] According to this embodiment of the invention, the driver, when sober, can start the engine 10 simply by undergoing alcohol detection outside the vehicle. On the other hand, the driver, when drunk, is prohibited from starting the engine 10. Therefore, drinking and driving can be prevented without increasing the bothersomeness in starting the engine 10.

[0060] The doors of the vehicle are unlocked regardless of the result of alcohol detection. Therefore, the driver, even when drunk, can be prevented from becoming unable to get into the vehicle.

[0061] Although the embodiments of the invention have been described above, the invention should not be limited to the foregoing embodiments thereof and can be subjected to various modifications. For example, in each of the foregoing embodiments of the invention, the power plant starting device according to the invention is applied to the gasoline vehicle designed to start the engine by means of the starter. However, the invention is also applicable to hybrid vehicles designed to start an engine by means of an electric motor, electric vehicles, and the like.

[0062] In each of the foregoing embodiments of the invention, the engine is prohibited from being started when the concentration of alcohol in the driver is equal to or higher than the reference value. However, it is also appropriate to adopt a configuration that allows the engine to be started but prohibits the vehicle from running by fixing a shift position to a parking position (P). If this configuration is adopted, the air-conditioning in the vehicle can be put into function by starting the engine in, for example, a land of severe cold or severe heat.