Inertial Sensor Test Function for Comprehensive System Verification
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Solution Overview
Problem
Existing inertial sensors, such as MEMS rate sensors, have limited capabilities for comprehensive testing, primarily allowing only connectivity checks, which provide limited information about the system's operation and do not adequately cover the entire system's functionality.
Innovation Solution
An angular velocity sensor with a ring-type structure incorporating primary and secondary channels, where the secondary channel includes test means to input signals out of phase, generating an offset indicative of the sensor's status, allowing for a more comprehensive system test by initiating and maintaining resonant oscillations and detecting movements using differential amplifiers and synchronous detectors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If only connectivity checks are performed for testing MEMS rate sensors, then the testing process is simple and quick, but the information obtained about system operation is limited and does not cover complete system functionality
Solution Approach 1:
The patent applies preliminary action by injecting test signals into the sensor system before actual operation to verify the functional status of internal components. The test signal injection circuit introduces controlled signals into the primary resonant structure, allowing the system to be tested in advance without requiring complex external testing equipment or procedures. This enables comprehensive system verification while maintaining operational simplicity.
2Reliability
If comprehensive testing of all sensor channels is implemented, then complete system operation can be verified, but the testing mechanism becomes more complex and requires additional components
Solution Approach 1:
The patent applies universality by designing a test signal injection circuit that can test multiple sensor channels and internal components through a single integrated mechanism. The same injection circuit can verify primary resonant structure, secondary resonant structure, amplifier channels, and phase-locked loops by appropriately configuring test signals. This multi-functional approach enables comprehensive system verification without requiring separate testing mechanisms for each component, thereby reducing overall system complexity while maintaining high reliability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enables a more thorough testing of the sensor's primary and secondary channels, ensuring correct operation of the MEMS transducers, amplifiers, and driver circuits, providing a measurable output that indicates the sensor's status and detects potential failures within the system.
Implementation Method 1
Piezoelectric primary drive means 4 are provided that cause the sensor to vibrate on supports (not shown)
Implementation Method 2
the primary channel comprising primary driver means for initiating and maintaining resonant oscillations in the primary elements
Implementation Method 3
the detecting means including a differential amplifier and synchronous detectors generating an output signal dependent upon the movement of the sensor
Implementation Method 4
the detecting means including a differential amplifier and synchronous detectors generating an output signal dependent upon the movement of the sensor
Data Source
AI summary
An inertial sensor is described that has a commanded test function. The sensor is of a ring type driven by a driver circuit, the sensor further includes primary and secondary portions having corresponding signal pickoffs. The primary pickoff signal amplitude is controlled via an automatic gain control, the primary phase lock loop and VCO locks to the resonant frequency to provide the clocks for the synchronous detectors, the primary pickoff signals via the primary phase shift circuit is provided to the primary driver, the secondary pickoff signal being input into a detector circuit capable of detecting motion in the sensor. The commanded test function includes a signal derived from the primary portion of the circuit and input into the two inputs of a differential amplifier in the secondary pickoff detector circuit.