System, method, and apparatus for classifying an occupant of a vehicle seat

A vehicle safety system comprising at least one vehicle occupant safety device, an airbag ECU, and a controller configured to determine an occupant classification, wherein the airbag ECU is configured to control actuation of the at least one vehicle occupant safety device in response to the occupant classification, and wherein the controller is configured to determine the occupant classification by:

• communicating with a first seat weight sensor to measure a first seat weight indication for the vehicle seat, wherein the first seat weight sensor is located on a lateral side of the vehicle seat at a front location on the vehicle seat;
• communicating with a second seat weight sensor to measure a second seat weight indication for the vehicle seat, wherein the second seat weight sensor is located on the lateral side of the vehicle seat at a rear location on the vehicle seat;
• communicating with a vehicle acceleration sensor to measure a vehicle acceleration value;
• determining a raw weight on the vehicle seat as twice the sum of the first and second seat weight indications;
• determining a filtered weight based on the raw weight, wherein the controller is configured to determine the filtered weight by selecting one of an unfiltered weight, a short filtered weight, and a long filtered weight, wherein the short filtered weight is determined using a low pass filter with a comparatively short time constant, and the long filtered weight is determined using a low pass filter with a comparatively long time constant;
• and
• determining the occupant class based on the filtered weight in response to the vehicle acceleration value being less than a predetermined value,
• wherein the occupant class is selected from one of the following classes:
• no occupant class, child seat class, small adult class, and large adult class,
• wherein the no occupant class is associated with measured seat weights up to a first weight, the child seat class is associated with measured seat weights ranging from the first weight up to a second weight, greater than the first weight, the small adult class is associated with measured seat weights ranging from the second weight up to a third weight, greater than the second weight, and the large adult class is associated with measured seat weights greater or equal to than the third weight, and
• wherein the first weight is 10.8 kg, the second weight is 29.4 kg, and the third weight is 54.8 kg.

A vehicle safety system comprising at least one vehicle occupant safety device, an airbag ECU, and a controller configured to determine an occupant classification, wherein the airbag ECU is configured to control actuation of the at least one vehicle occupant safety device in response to the occupant classification, and wherein the controller is configured to determine the occupant classification by:

• communicating with a first seat weight sensor to measure a first seat weight indication for the vehicle seat, wherein the first seat weight sensor is located on a lateral side of the vehicle seat at a front location on the vehicle seat;
• communicating with a second seat weight sensor to measure a second seat weight indication for the vehicle seat, wherein the second seat weight sensor is located on the lateral side of the vehicle seat at a rear location on the vehicle seat;
• communicating with a vehicle acceleration sensor to measure a vehicle acceleration value;
• determining a raw weight on the vehicle seat as twice the sum of the first and second seat weight indications;
• determining a filtered weight based on the raw weight, wherein the controller is configured to determine the filtered weight by selecting one of an unfiltered weight, a short filtered weight, and a long filtered weight, wherein the short filtered weight is determined using a low pass filter with a comparatively short time constant, and the long filtered weight is determined using a low pass filter with a comparatively long time constant;
• and
• determining the occupant class based on the filtered weight in response to the vehicle acceleration value being less than a predetermined value, wherein the controller is configured to select one of an unfiltered weight, a short filtered weight, and a long filtered weight by:
• selecting the unfiltered weight for a predetermined startup time;
• selecting the short filtered weight after the startup time expires;
• selecting the long filtered weight in response to determining that the vehicle is moving and the seat is occupied;
• and
• selecting the short filtered weight in response to determining that the vehicle is not moving and the seat is unoccupied.

A vehicle safety system comprising at least one vehicle occupant safety device, an airbag ECU, and a controller configured to determine an occupant classification, wherein the airbag ECU is configured to control actuation of the at least one vehicle occupant safety device in response to the occupant classification, and wherein the controller is configured to determine the occupant classification by:

• communicating with a first seat weight sensor to measure a first seat weight indication for the vehicle seat, wherein the first seat weight sensor is located on a lateral side of the vehicle seat at a front location on the vehicle seat;
• communicating with a second seat weight sensor to measure a second seat weight indication for the vehicle seat, wherein the second seat weight sensor is located on the lateral side of the vehicle seat at a rear location on the vehicle seat;
• communicating with a vehicle acceleration sensor to measure a vehicle acceleration value;
• determining a raw weight on the vehicle seat as twice the sum of the first and second seat weight indications;
• determining a filtered weight based on the raw weight, wherein the controller is configured to determine the filtered weight by selecting one of an unfiltered weight, a short filtered weight, and a long filtered weight, wherein the short filtered weight is determined using a low pass filter with a comparatively short time constant, and the long filtered weight is determined using a low pass filter with a comparatively long time constant;
• and
• determining the occupant class based on the filtered weight in response to the vehicle acceleration value being less than a predetermined value, wherein the controller is configured to select one of an unfiltered weight, a short filtered weight, and a long filtered weight by:
• selecting the unfiltered weight for an initial startup time;
• selecting the short filtered weight until the vehicle is moving and the seat is occupied;
• and
• thereafter selecting the long filtered weight until the vehicle stops moving.