Resolver Front-End Circuit for Signal Attenuation and Fault Detection
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Solution Overview
Problem
Existing resolver systems face challenges in efficiently attenuating sensing signals for processing circuits without the need for large amplifiers, which increase cost and size, and lack effective fault detection mechanisms.
Innovation Solution
A front end architecture for resolvers that attenuates sensing signals using resistors and capacitors, enabling fault detection without amplifiers, and includes a processing circuit to identify faults such as shorts, opens, and coil issues based on common mode voltage analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If amplifiers are used to attenuate sensing signals, then signal processing capability is improved, but device size and cost increase
Solution Approach 1:
The patent replaces the mechanical/electronic amplifier system with a purely resistive voltage divider network. The sensing signals are attenuated by connecting resistors in series between the signal source and ground, creating voltage division ratios that achieve the desired attenuation without requiring active amplifier components. This substitution eliminates the need for complex amplifier circuits while maintaining signal processing functionality.
Solution Approach 2:
The patent uses simple, inexpensive resistors instead of costly amplifier components. The resistive voltage divider network employs basic passive components that are significantly cheaper and simpler than active amplifier devices, reducing both component cost and overall device complexity while achieving the same signal attenuation function.
2Measurement precision
If traditional resolver systems are used, then position sensing is provided, but fault detection capability is lacking
Solution Approach 1:
The patent incorporates fault detection by monitoring the voltage at the non-inverting input of the amplifier, which is connected to the resistive voltage divider network. The system continuously checks this voltage to detect faults such as resistor failures, open circuits, or short circuits. When a fault is detected through this feedback mechanism, the system can generate appropriate error signals or shutdown commands to prevent incorrect operation.
Solution Approach 2:
The patent uses the common mode voltage signal as an intermediary for fault detection. The voltage at the non-inverting input, which serves as the common mode reference, is monitored to detect faults in the resistive voltage divider network. This intermediary signal provides information about the health of the attenuation circuit without interfering with the normal position sensing function.
3Device complexity
If signal attenuation is performed without amplifiers, then device cost is reduced, but fault detection becomes more difficult
Solution Approach 1:
The patent incorporates feedback by connecting the non-inverting input of the amplifier to the voltage divider network formed by the resistors. This feedback connection allows the system to monitor the attenuation circuit's voltage levels and detect faults such as resistor failures or open circuits, making fault detection easier despite the simpler attenuation architecture.
Solution Approach 2:
The patent makes the resistive voltage divider network serve multiple functions: it provides signal attenuation for the position sensing signals while simultaneously serving as a fault detection sensor. The same resistors that attenuate the signals also create a voltage divider that can be monitored for fault conditions, eliminating the need for separate fault detection components and reducing overall device cost.
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 allows for efficient signal attenuation and fault detection in resolver systems, reducing costs and size while ensuring reliable operation by identifying various fault conditions.
Implementation Method 1
a measuring transformer coil (118) having first and second terminals
Implementation Method 2
a first resistor (202) having first and second terminals, the first terminal of the first resistor coupled to a voltage supply terminal, and the second terminal of the first resistor coupled to the first terminal of the measuring transformer coil
Data Source
AI summary
In some examples, a method includes applying a bias voltage to a resolver system. The method also includes receiving a sensed signal, the sensed signal varying in value based on a position of a rotary element. The method also includes attenuating the sensed signal to form an attenuated signal. The method also includes performing fault detection on the attenuated signal to detect faults in the resolver system. The method also includes processing the attenuated signal to determine the position of the rotary element.