Start controlling method for a passenger protection system, and start controlling system for a passenger protection system, and recording medium for recording start control program for passenger protection system

A start controlling system for controlling start of a passenger protection system which is so constructed that a protection system for protecting a passenger in a vehicle can be started in response to a start signal, said start controlling system comprising:

• an acceleration deciding means for deciding whether or not an acceleration of the vehicle exceeds a predetermined magnitude,
• a speed integral value calculating means for calculating a speed integral value by executing a time integral of a succeedingly detected acceleration for a predetermined time if it is decided by said acceleration deciding means that the acceleration is in excess of the predetermined magnitude;
• a line segment length calculating means for calculating a length of a line segment of the acceleration succeedingly detected for the predetermined time with a passage of time;
• a rate deciding means for calculating a rate of an increment of time integral to the length of the line segment for the predetermined time, to decide whether or not the rate is smaller than a predetermined value;
• a threshold value calculating means for calculating a threshold value serving as a reference to decide whether or not the passenger protection system is started, based on the acceleration of the vehicle,
• a threshold value changing means for changing the threshold value being calculated by said threshold value calculating means so as to not start the passenger protection system if it is decided by said rate deciding means that the rate is smaller than the predetermined value;
• and
• a start signal deciding/generating means for deciding whether or not the speed integral value calculated by said speed integral value calculating means exceeds the threshold value changed by said threshold value changing means if it is decided by said rate deciding means that the rate is smaller than the predetermined value, then deciding whether or not the speed integral value calculated by said speed integral value calculating means exceeds the threshold value calculated by said threshold value calculating means if it is decided by said rate deciding means that the rate is larger than the predetermined value, and then generating a start signal for the passenger protection system if it is decided in either case that the speed integral value exceeds the threshold value.

A start controlling system for controlling start of a passenger protection system which is so constructed that a protection system for protecting a passenger in a vehicle can be started in response to a start signal, said start controlling system comprising:

• a microcomputer operable to execute predetermined processes by reading a predetermined program from an external device and executing the predetermined program, wherein said microcomputer is operable to:
• decide whether or not an acceleration of the vehicle exceeds a predetermined magnitude, and then calculate a speed integral value by executing a time integral of a succeedingly detected acceleration for a predetermined time if it is decided that the acceleration exceeds the predetermined magnitude,
• calculate a length of a line segment of the acceleration succeedingly detected for the predetermined time with a passage of time, then calculate a rate of an increment of a speed integral value to the length of the line segment for the predetermined time, and then decide whether or not the rate of the increment of the speed integral value to the length of the line segment for the predetermined time is smaller than a predetermined value,
• calculate a threshold value serving as a reference to decide whether or not the passenger protection system is started, based on the acceleration of the vehicle,
• perform first decision processing, when the rate of the increment of the speed integral value to the length of the line segment for the predetermined time is decided to be smaller than the predetermined value, in order to change the threshold value in a direction to prevent start of the passenger protection system and to decide whether or not the speed integral value exceeds the changed threshold value,
• perform second decision processing, when the rate of the increment of the speed integral value to the length of the line segment for the predetermined time is decided to be larger than the predetermined value, in order to decide whether or not the speed integral value exceeds the threshold value before the change to the threshold value, and
• output a digital start signal for starting the passenger protection system if it is decided in the first decision processing that the speed integral value has exceeded the changed threshold value or it is decided in the second decision processing that the speed integral value has exceeded the threshold value before the change to the threshold value;
• a digital/analogue converter operable to convert the digital start signal to be supplied from said microcomputer to an air bag system into an analogue signal;
• and
• an interface circuit operable to convert the analogue signal of said digital/analogue converter into a predetermined signal suitable for the air bag system.

A start controlling system for controlling start of a passenger protection system which is so constructed that a protection system for protecting a passenger in a vehicle can be started in response to a start signal, said start controlling system comprising:

• an acceleration deciding means for deciding whether or not an acceleration of the vehicle exceeds a predetermined magnitude;
• a speed integral value calculating means for calculating a speed integral value by executing a time integral of a succeedingly detected acceleration for a predetermined time if it is decided by said acceleration deciding means that the acceleration is in excess of the predetermined magnitude,
• a line segment length calculating means for calculating a length of a line segment of the acceleration succeedingly detected for the predetermined time with a passage of time;
• a rate detecting means for calculating a rate of an increment of a speed integral value to the length of the line segment for the predetermined time, to decide whether or not the rate is smaller than a predetermined value;
• a speed integral value changing means for changing the speed integral value calculated by said speed integral value calculating means to reduce the speed integral value's absolute value if it is decided by said rate deciding means that the rate is smaller than the predetermined value;
• a threshold value calculating means for calculating a threshold value serving as a reference to decide whether or not the passenger protection system is started, based on the acceleration of the vehicle after it is decided by said rate deciding means that the rate is not smaller than the predetermined value or after the speed integral value is changed by said speed integral value changing means;
• and
• a start signal deciding/generating means for deciding whether or not the speed integral value exceeds the threshold value calculated by said threshold value calculating means, and then generating a start signal for the passenger protection system if it is decided that the speed integral value exceeds the threshold value.

A start controlling system for controlling start of a passenger protection system which is so constructed that a protection system for protecting a passenger in a vehicle can be started in response to a start signal, said start controlling system comprising:

• a microcomputer operable to execute predetermined processes by reading a predetermined program from an external device and executing the predetermined program, wherein said microcomputer is further operable to:
• decide whether or not an acceleration of the vehicle exceeds a predetermined magnitude, and then calculate a speed integral value by executing a time integral of a succeedingly detected acceleration for a predetermined time if it is decided that the acceleration exceeds the predetermined magnitude,
• calculate a length of a line segment of the acceleration succeedingly detected for the predetermined time with a passage of time, then calculate a rate of an increment of a speed integral value to the length of the line segment for the predetermined time, and then decide whether or not the rate of the increment of the speed integral value to the length of the line segment for the predetermined time is smaller than a predetermined value,
• change the speed integral value to reduce the speed integral value's absolute value if it is decided that the rate of the increment of the speed integral value to the length of the line segment for the predetermined time is smaller than the predetermined value,
• calculate a threshold value serving as a reference to decide whether or not the passenger protection system is started, based on the acceleration of the vehicle, after the speed integral value is changed or after it is decided that the rate of the increment of the speed integral value to the length of the line segment for the predetermined time is not smaller than the predetermined value, then decide whether or not the changed speed integral value exceeds the threshold value, and then generate a digital start signal of the passenger protection system if it is decided that the speed integral value exceeds the threshold value;
• a digital/analogue converter operable to convert the digital start signal to be supplied from said microcomputer to an air bag system into an analogue signal;
• and
• an interface circuit for converting the analogue signal of said digital/analogue converter into a predetermined signal suitable for the air bag system.

A computer program embodied on a computer readable medium for use with a computer, said computer program comprising:

• computer readable program code operable to cause the computer to decide whether or not an acceleration of a vehicle exceeds a predetermined value;
• computer readable program code operable to cause the computer to execute a time integral of a succeedingly input acceleration for a predetermined time if it is decided that the acceleration of the vehicle exceeds the predetermined value;
• computer readable program code operable to cause the computer to calculate a length of a line segment of the succeedingly input acceleration for the predetermined time with a passage of time if it is decided that the acceleration of the vehicle exceeds the predetermined value;
• computer readable program code operable to cause the computer to calculate a rate of an increment of time integral to the length of the line segment for the predetermined time;
• computer readable program code operable to cause the computer to decide whether or not the rate is below a predetermined value;
• computer readable program code operable to cause the computer to decide that the acceleration is a generation of a resonance if it is decided that the rate is below the predetermined value, and then cause the computer to calculate a threshold value serving as a reference to decide whether or not the passenger protection system is started, according to a predetermined relation based on the acceleration;
• computer readable program code operable to cause the computer to change the threshold value such that start of the passenger protection system can be avoided;
• computer readable program code operable to cause the computer to decide whether or not the speed integral value exceeds the changed threshold value;
• computer readable program code operable to cause the computer to generate a start signal of the passenger protection system if it is decided that the speed integral value exceeds the changed threshold value;
• computer readable program code operable to cause the computer to decide whether or not the speed integral value exceeds the threshold value, which is calculated according to the predetermined relation based on the acceleration and serves as the reference to decide whether or not the passenger protection system is started, if it is decided that the rate of the increment of time integral to the length of the line segment for the predetermined time is not below the predetermined value;
• and
• computer readable program code operable to cause the computer to generate the start signal of the passenger protection system if it is decided that the speed integral value exceeds the threshold value which is calculated according to the predetermined relation based on the acceleration and serves as the reference to decide whether or not the passenger protection system is started.

A computer program embodied on a computer readable medium for use with a computer, said computer program comprising:

• computer readable program code operable to cause the computer to decide whether or not an acceleration of a vehicle exceeds a predetermined value;
• computer readable program code operable to cause the computer to execute a time integral of a succeedingly input acceleration for a predetermined time if it is decided that the acceleration of the vehicle exceeds the predetermined value;
• computer readable program code operable to cause the computer to calculate a length of a line segment of the succeedingly input acceleration for the predetermined time with a passage of time if it is decided that the acceleration of the vehicle exceeds the predetermined value;
• computer readable program code operable to cause the computer to calculate a rate of an increment of time integral to the length of the line segment for the predetermined time;
• computer readable program code operable to cause the computer to decide whether or not the rate of the increment of time integral to the length of the line segment for the predetermined time is below the predetermined value;
• computer readable program code operable to cause the computer to decide that the acceleration is a generation of a resonance if it is decided that the rate of the increment of time integral to the length of the line segment for the predetermined time is below the predetermined value, and then cause the computer to change the speed integral value such that start of the passenger protection system can be avoided;
• computer readable program code operable to cause the computer to decide whether or not the changed speed integral value exceeds a threshold value which is calculated according to a predetermined relation based on the acceleration and serves as a reference to decide whether or not the passenger protection system is started;
• computer readable program code operable to cause the computer to generate a start signal of the passenger protection system if it is decided that the chanced speed integral value exceeds the threshold value;
• computer readable program code operable to cause the computer to decide whether or not the speed integral value exceeds the threshold value, which is calculated according to the predetermined relation based on the acceleration and serves as the reference to decide whether or not the passenger protection system is started, if it is decided that the rate of the increment of time integral to the length of the line segment for the predetermined time is not below the predetermined value;
• and
• computer readable program code operable to cause the computer to generate the start signal of the passenger protection system if it is decided that the speed integral value exceeds the threshold value.