Communication apparatus and method of airbags for a vehicle
AssigneeDenso Corporation
InventorNobuo Mayumi
Life of this patent
Estimating the term…
Abstract
A communication apparatus in an airbag system includes an airbag ECU as a master unit, sets of communication lines and slave sensor devices. The slave sensor devices are respectively connected to the airbag ECU through the set of communication lines. The airbag ECU transmits data transmission request commands to the respective sets of communication lines at timings which are different from each other. Thus, transmission timings in the respective sets of communication lines are prevented from being synchronized, and noise which develops in consequence of the data communications between the master unit and the slave sensor devices can be reduced.
Claims15
A communication apparatus comprising:
- a master unit;
- a plurality of sets of communication lines connected to the master unit;
- and
- a plurality of slave units connected to each of the plurality of sets of communication lines,
- wherein the master unit serially transmits data transmission request commands each of which specifies the master device as a subject for communications and makes a request for transmission of data to each of the plurality of sets of communication lines in synchronism with a clock of predetermined period,
- wherein each of the slave units determines whether it is the subject for communications on the basis of the data transmission request command, and in case of the subject for communications serially transmits the data corresponding to the data transmission request command to the master unit,
- wherein the master unit serially transmits the data transmission request commands at timings which are different in a predetermined time interval from each other among the sets of communication lines,
- wherein the master unit simultaneously communicates with the plurality of sets of communication lines,
- wherein the predetermined time interval is one half of a cycle period of the clock, and
- wherein the master unit, the sets of communication lines and the slave units are mounted on a vehicle so that the master unit activates airbags.
A communication method in a vehicle having airbags, a master unit, a first plurality of slave units provided at a right side of the vehicle to detect accelerations, a second plurality of slave units provided at a left side of the vehicle to detect accelerations, a first communication line connecting the master unit and the first plurality of slave units, and a second communication line separate from the first communication line, the second communication line connecting the master unit and the second plurality of slave units, the method comprising:
- generating a clock at every predetermined interval;
- transmitting first data request commands from the master unit to the first plurality of slave units through the first communication line serially at first timings which are in timed relation with the clock;
- transmitting second data request commands from the master unit to the second plurality of slave units through the second communication line serially at second timings which are in timed relation with the clock, the second timings are delayed from the first timings a delay period which is other than an integer times of the predetermined interval;
- wherein
- the master unit simultaneously communicates through the first and second communication lines, and
- the first plurality of slave units and the second plurality of slave units transmit acceleration detection results in response to the first data request commands and the second data request commands, respectfully, so that the master unit activates the air bags in response to the acceleration detection results.
A communication apparatus in a vehicle having airbags comprising:
- a master unit;
- a first plurality of slave units provided at a right side of the vehicle to detect accelerations;
- a second plurality of slave units provided at a left side of the vehicle to detect accelerations;
- a first set of communication lines electrically connecting the master unit with the first plurality of slave units;
- a second set of communication lines electrically connecting the master unit with the second plurality of slave units;
- wherein
- the master unit serially transmits data transmission request commands each of which specifies the master device as a subject for communications and makes a request for transmission of data to each of the first and second sets of communication lines in synchronism with a clock of predetermined period;
- each of the slave units determines whether it is the subject for communications on the basis of the data transmission request command, and in case of the subject for communications serially transmits the data corresponding to the data transmission request command to the master unit;
- the master unit serially transmits the data transmission request commands at timings which are different in a predetermined time interval from each other between the first and second sets of communication lines;
- the master unit simultaneously communicates with the first and second communication lines;
- and
- the first plurality of slave units and the second plurality of slave units transmit acceleration detection results in response to the first data request commands and the second data request commands, respectfully, so that the master unit activates the air bags in response to the acceleration detection results.
Dependencies are inferred from the claim text.