Vehicle Seat Occupant Detection Using Capacitance and Weight Sensors

The patent combines a capacitance-based detection system with a weight-based detection system into a single integrated occupant detection device. The capacitance sensor detects changes in electrical field coupling, while the weight sensor measures the mass of the occupant. By merging these two detection mechanisms, the system achieves both the sensitivity of capacitance detection and the discrimination capability of weight measurement, resolving the contradiction between detection accuracy and distinguishing capability.

The patent introduces a controller as an intermediary that processes signals from both the capacitance sensor and the weight sensor. The controller compares and correlates the signals from both sensors to determine the actual occupant status. This intermediary processing layer enables the system to distinguish between false positives (moisture, empty seats) and true positives (actual occupants) by requiring consistent signals from both detection mechanisms.

The weight sensor acts as an intermediary verification mechanism that filters out false detections caused by moisture. While the capacitance sensor may detect coupling from moisture, the weight sensor will not register the corresponding mass, allowing the controller to identify and reject false positive signals. This intermediary check significantly improves detection reliability in the presence of moisture interference.

The system uses feedback from the weight sensor to validate or invalidate signals from the capacitance sensor. When the capacitance sensor detects coupling but the weight sensor does not detect corresponding mass, the system receives feedback indicating a false positive condition. This feedback mechanism allows the system to adapt its detection logic and maintain high reliability even when moisture is present on the seat.

The patent merges a capacitance-based detection module with a weight-based detection module into an integrated system. The capacitance module provides simple, contactless detection of occupancy presence, while the weight module adds classification capability. By combining these two relatively simple modules, the system achieves high measurement precision for occupancy classification without excessively increasing overall device complexity.

The integrated detection system serves multiple functions simultaneously: it detects occupancy presence, classifies occupant type (adult, child, empty seat), and provides moisture detection capability. This multi-functionality is achieved by having the combined sensor system perform different analytical tasks based on the same physical measurements, thereby improving classification accuracy without proportionally increasing device complexity.