System and method for fail-safe excitation of a rotary transformer

Abstract

The present disclosure relates to systems and methods for fail-safe rotary transformer excitation. The method includes generating a rotary transformer excitation signal and providing the rotary transformer excitation signal to an input of a first rotary transformer control circuit and an input of a second rotary transformer control circuit. The method further includes, in response to the first rotary transformer control circuit detecting a fault in the rotary transformer excitation signal provided to the first rotary transformer control circuit: biasing a first rotary transformer amplifier using the first rotary transformer control circuit; and communicating, via a communication bus between the first rotary transformer control circuit and the second rotary transformer control circuit, an indication to the second rotary transformer control circuit that the first rotary transformer control circuit detected the fault in the rotary transformer excitation signal provided to the first rotary transformer control circuit.

Description

Technical Field

[0001] This disclosure relates to vehicle circuitry, and more specifically, to systems and methods for excitation of fail-safe resolver transformers. Background Technology

[0002] Vehicles (such as cars, trucks, SUVs, crossovers, minivans, or other suitable vehicles) typically include various electric motors, such as permanent magnet motors or other suitable electric motors. These motors are used in various aspects of vehicle control or operation, such as vehicle propulsion or other suitable aspects of vehicle control or operation. These motors may be associated with a rotary transformer for detecting the speed and position of the motor. The vehicle's controller can use the detected speed and position of the motor to control various aspects of the vehicle. Summary of the Invention

[0003] This disclosure generally relates to electric motor control.

[0004] One aspect of the disclosed embodiments includes a method for exciting a fail-safe rotary transformer. The method includes: generating a rotary transformer excitation signal; providing the rotary transformer excitation signal to an input of a first rotary transformer control circuit and an input of a second rotary transformer control circuit; and in response to the first rotary transformer control circuit detecting a fault in the rotary transformer excitation signal provided to the first rotary transformer control circuit, setting a first switch of the first rotary transformer control circuit from a first position to a second position; and providing a first output signal via the first switch to a first rotary transformer amplifier, the first output signal having an output frequency and amplitude corresponding to the rotary transformer excitation signal.

[0005] Another aspect of the disclosed embodiments includes a system for excitation of a fail-safe rotary transformer. The system includes a controller having a processor and a memory, the memory including instructions that, when executed by the controller, cause the controller to: generate a rotary transformer excitation signal; and provide the rotary transformer excitation signal to inputs of a first rotary transformer control circuit and a second rotary transformer control circuit. In response to detecting a fault in the rotary transformer excitation signal provided to the first rotary transformer control circuit, the first rotary transformer control circuit: sets a first switch of the first rotary transformer control circuit from a first position to a second position; and provides a first output signal via the first switch to a first rotary transformer amplifier, the first output signal having an output frequency and amplitude corresponding to the rotary transformer excitation signal.

[0006] Another aspect of the disclosed embodiment includes an apparatus for excitation of a fail-safe rotary transformer. The apparatus includes a controller configured to: generate a rotary transformer excitation signal; and provide the rotary transformer excitation signal to inputs of a first rotary transformer control circuit and a second rotary transformer control circuit. In response to detecting a fault in the rotary transformer excitation signal provided to the first rotary transformer control circuit, the first rotary transformer control circuit: sets a first switch of the first rotary transformer control circuit from a first position to a second position; and provides a first output signal via the first switch to a first rotary transformer amplifier, the first output signal having an output frequency and amplitude corresponding to the rotary transformer excitation signal. In response to detecting a fault in the rotary transformer excitation signal provided to the second rotary transformer control circuit, the second rotary transformer control circuit: sets a second switch of the second rotary transformer control circuit from a first position to a second position; and provides a second output signal via the second switch to a second rotary transformer amplifier, the second output signal having an output frequency and amplitude corresponding to the rotary transformer excitation signal.

[0007] Another aspect of the disclosed embodiments includes a method for exciting a fail-safe rotary transformer. The method includes: generating a rotary transformer excitation signal; and providing the rotary transformer excitation signal to an input of a first rotary transformer control circuit and an input of a second rotary transformer control circuit. The method further includes, in response to the first rotary transformer control circuit detecting a fault in the rotary transformer excitation signal provided to the first rotary transformer control circuit, using the first rotary transformer control circuit to bias a first rotary transformer amplifier; and transmitting, via a communication bus between the first and second rotary transformer control circuits, an indication that the first rotary transformer control circuit detected a fault in the rotary transformer excitation signal provided to the first rotary transformer control circuit.

[0008] Another aspect of the disclosed embodiments includes a system for excitation of a fail-safe rotary transformer. The system includes a controller having a processor and a memory. The memory includes instructions that, when executed by the controller, cause the controller to: generate a rotary transformer excitation signal; and provide the rotary transformer excitation signal to inputs of a first rotary transformer control circuit and a second rotary transformer control circuit. The first rotary transformer control circuit is configured to, in response to detecting a fault in the rotary transformer excitation signal provided to the first rotary transformer control circuit,: bias a first rotary transformer amplifier; and transmit, via a communication bus between the first and second rotary transformer control circuits, an indication that the first rotary transformer control circuit has detected a fault in the rotary transformer excitation signal provided to the first rotary transformer control circuit.

[0009] These and other aspects of this disclosure are set forth in the following detailed description of the embodiments, the appended claims, and the accompanying drawings. Attached Figure Description

[0010] This disclosure can be best understood from the following detailed description when read in conjunction with the accompanying drawings. It should be emphasized that, by convention, the various features in the drawings are not drawn to scale. Instead, for clarity, the dimensions of the various features have been arbitrarily enlarged or reduced.

[0011] Figure 1 The vehicle is generally illustrated according to the principles of this disclosure.

[0012] Figure 2 A controller based on the principles of this disclosure is generally illustrated.

[0013] Figure 3 A fail-safe rotary transformer excitation system based on the principles of this disclosure is generally illustrated.

[0014] Figure 4 This is a flowchart illustrating a method for measuring motor cycle based on phase voltage according to the principles of this disclosure. Detailed Implementation

[0015] The following discussion pertains to various embodiments of the invention. While one or more of these embodiments may be preferred, the disclosed embodiments should not be construed as limiting the scope of this disclosure, including the claims. Furthermore, those skilled in the art will understand that the following description has broad application, and the discussion of any embodiment is intended only as an example of that embodiment and not to imply that the scope of this disclosure, including the claims, is limited to that embodiment.

[0016] As described, vehicles (e.g., cars, trucks, SUVs, crossovers, minivans, or other suitable vehicles) typically include various electric motors, such as permanent magnet motors or other suitable electric motors. Such motors can be used in various aspects of vehicle control or operation, such as vehicle propulsion or other suitable aspects of vehicle control or operation. These motors may be associated with a rotary transformer for detecting the speed and position of the motor. The vehicle's controller can use the detected speed and position of the motor to control various aspects of the vehicle.

[0017] Such resolvers can be prone to various single points of failure. Potential single points of failure associated with resolvers may include external power supplies associated with the resolver (e.g., failure at one or more inputs of the power supply, power supply failure, failure at the power supply output or connection to the associated microprocessor or controller, etc.), microprocessors or controllers associated with the resolver (e.g., failure of the microprocessor's power supply connection, failure of the microprocessor to provide an analog pulse width modulation signal, and inability to generate a usable sine wave, etc.), active filters associated with the resolver (e.g., active filters not powered during power failures or connection problems, which may result in no input excitation being provided to the corresponding resolver amplifier, etc.), passive filters associated with the resolver (e.g., inability to provide input excitation to the resolver amplifier), resolver amplifiers (e.g., power supply to the output amplifier not working, connection problems preventing the resolver amplifier from operating, etc., which may result in insufficient excitation of the resolver), and so on.

[0018] Typically, when a resolver encounters any such single point of failure, there may be a lack of useful sine or cosine output from the resolver's secondary windings, which could prevent the system associated with the resolver from maintaining a safe operating condition (e.g., because knowledge about the motor speed or position is unavailable or unattainable).

[0019] In a typical system, the excitation signal at the primary input of the resolver can be executed in a serial path. This method involves various components and connections within the serial path. A failure in any of these components or connections can result in a single point of failure. Such a failure will lead to the loss of speed and position information of the monitored motor.

[0020] Therefore, systems and methods configured to provide fail-safe rotary transformer excitation, such as those described herein, may be required. In some embodiments, the systems and methods described herein can be configured to provide fail-safe rotary transformer output signals, wherein each end of the rotary transformer primary coil is driven by an independent rotary transformer excitation circuit. Apart from a rotary transformer-to-rotor communication bus, the excitation circuits can be electrically isolated from each other. In some embodiments, the independent excitation circuits can be contained within two separate silicon wafers.

[0021] In some embodiments, a microprocessor or controller associated with the resolver can generate a resolver excitation signal. The systems and methods described herein can be configured to apply the resolver excitation signal to the corresponding resolver excitation input of each resolver excitation circuit. In some embodiments, each resolver excitation circuit includes configurable logic that can be configured to detect the loss or unexpected deviation of the expected resolver excitation input at one or both resolver excitation inputs over a wide range of input frequencies.

[0022] In some implementations, each resolver excitation circuit may include independent internal resolver exciter waveform generator logic, which can be used to provide an exciter excitation waveform to the corresponding resolver amplifier. Each resolver excitation waveform generator logic may be configured to provide the same output frequency and amplitude as the resolver excitation signal generated and provided by the microprocessor.

[0023] In some embodiments, the systems and methods described herein can be configured to, prior to detecting a fault in the resolver excitation input of any resolver excitation circuit, set a logic switch (e.g., a logic switch associated with each respective resolver excitation circuit) such that the resolver excitation input provided by the microprocessor is used as the input of each respective resolver amplifier.

[0024] In some embodiments, the systems and methods described herein can be configured to, if an input fault is detected in any one or two resolver excitation circuits, set a corresponding logic switch (e.g., in the faulty resolver excitation circuit) such that if the resolver still requires a resolver excitation signal, the resolver excitation signal provided by the microprocessor will not be provided to the corresponding resolver amplifier. The systems and methods described herein can also be configured to, in response to a fault in one or both resolver excitation circuits, provide input to the corresponding resolver amplifier via the corresponding resolver exciter waveform generator logic.

[0025] In some embodiments, the systems and methods described herein can be configured to bias the corresponding resolver amplifier (e.g., this may include fixing the resolver amplifier to a mid-supply voltage) if a fault is detected in the first resolver excitation circuit (but not, for example, in the second resolver excitation circuit). The systems and methods described herein can be configured to provide information indicating a fault in the first resolver excitation circuit to the second resolver excitation circuit via an inter-amplifier communication bus. The systems and methods described herein can be configured to double the gain of the second resolver amplifier using second resolver control circuitry in response to receiving information indicating a fault in the first resolver excitation circuit (e.g., this could allow the same excitation voltage to be provided to the resolver before any fault is detected). The systems and methods described herein can be configured to use a microprocessor to obtain motor speed and position via a resolver interface.

[0026] In some embodiments, the systems and methods described herein can be configured to bias the corresponding resolver amplifier (e.g., this may include fixing the resolver amplifier to a median voltage) if a fault is detected in the second resolver excitation circuit (but not, for example, in the first resolver excitation circuit). The systems and methods described herein can be configured to provide information indicating a fault in the second resolver excitation circuit to the first resolver excitation circuit via an inter-amplifier communication bus. The systems and methods described herein can be configured to double the gain of the first resolver amplifier using first resolver control circuitry in response to receiving information indicating a fault in the second resolver excitation circuit (e.g., this could allow the same excitation voltage to be provided to the resolver before any fault is detected). The systems and methods described herein can be configured to obtain motor speed and position via a resolver interface using a microprocessor.

[0027] In some implementations, the systems and methods described herein can be configured to ensure that the outputs of the two resolver amplifiers do not operate out of phase with each other in response to fixing the resolver amplifier associated with the faulty resolver excitation circuit to the neutral voltage, thereby affecting the output values ​​and waveforms (e.g., because it is no longer possible to keep the two signals in phase with each other).

[0028] In some implementations, the systems and methods described herein can be configured to, in response to the detection of a fault in either the first or second resolver excitation circuit, fix the associated resolver amplifier (e.g., using the first resolver excitation circuit) to a median voltage and drive the resolver at double the programmed gain using the generated exciter waveform (e.g., using the resolver amplifier associated with the second resolver excitation circuit).

[0029] In some embodiments, the systems and methods described herein can be configured to use independent power supplies for corresponding power logic to reduce or eliminate single points of failure within the excitation circuits of individual resolvers. In some embodiments, the systems and methods described herein can be configured to supply power from the resolver to individual resolver amplifiers. In some embodiments, the systems and methods described herein can be configured to continuously drive the primary of the resolver and provide speed and position information for the motor (e.g., in the presence of numerous single points of failure).

[0030] In some embodiments, the system and method can be configured to drive the resolver (e.g., in opposite phases) using a first resolver excitation circuit and a second resolver excitation circuit under normal or desired operating conditions. The system and method described herein can be configured to detect faults using both the first and second resolver excitation circuits. The system and method described herein can be configured to set one resolver excitation circuit to a neutral voltage while the other resolver excitation circuit doubles the amplitude to maintain the originally programmed total amplitude. The system and method described herein can be configured to perform these functions under numerous single points of failure, including the loss of a digital core in an integrated circuit (e.g., a resolver excitation circuit). The system and method described herein can be configured to coordinate the two resolver excitation circuits using a communication bus between them.

[0031] It should be understood that although the described system and method set one resolver excitation circuit to the neutral voltage while using another resolver excitation circuit to double the gain of the corresponding resolver amplifier (e.g., during fault mode), the resolver outputs of the two resolver excitation circuits may not be synchronized (e.g., if both resolver excitation circuits continuously drive the resolver, it may result in signal cancellation and / or harmonic distortion (due to different frequencies)).

[0032] In some embodiments, the systems and methods described herein can be configured to generate a resolver excitation signal. The systems and methods described herein can be configured to provide the resolver excitation signal to inputs of a first resolver control circuit and a second resolver control circuit. In some embodiments, the first resolver control circuit is independent of the second resolver control circuit. In some embodiments, the first resolver control circuit is disposed on a first silicon element, and the second resolver control circuit is disposed on a second element separate from the first silicon element.

[0033] The system and method described herein can be configured to, in response to a first resolver control circuit detecting a fault in the resolver excitation signal provided to the first resolver control circuit, set a first switch of the first resolver control circuit from a first position to a second position, and provide a first output signal having an output frequency and amplitude programmed in a local memory to the first resolver amplifier via the first switch.

[0034] In some embodiments, the systems and methods described herein can be configured to set a first switch to a first position before a first resolver control circuit detects a fault in the resolver excitation signal provided to the first resolver control circuit. The systems and methods described herein can also be configured to provide the resolver excitation signal provided to the first resolver control circuit to a first resolver amplifier in response to the first switch being set to the first position.

[0035] In some embodiments, the systems and methods described herein can be configured to fix the first resolver control circuit to a neutral voltage in response to the first resolver control circuit detecting a fault in the resolver excitation signal provided to the first resolver control circuit. The systems and methods described herein can also be configured to double the gain of the second resolver amplifier using the second resolver control circuit in response to receiving an indication from the second resolver control circuit via a communication bus between the first and second resolver control circuits that the first resolver control circuit has been set to a neutral voltage.

[0036] In some embodiments, the system and method described herein can be configured to, in response to the second resolver control circuit detecting a fault in the resolver excitation signal provided to the second resolver control circuit, set a second switch of the second resolver control circuit from a first position to a second position, and provide a second output signal having an output frequency and amplitude programmed in a local memory to the second resolver amplifier via the second switch.

[0037] In some embodiments, the system and method described herein can be configured to set a second switch to a first position before the second resolver control circuit detects a fault in the resolver excitation signal provided to the second resolver control circuit. The system and method described herein can also be configured to provide the resolver excitation signal provided to the second resolver control circuit to the second resolver amplifier in response to the second switch being set to the first position.

[0038] In some embodiments, the systems and methods described herein can be configured to fix the second resolver control circuit to a neutral voltage in response to the second resolver control circuit detecting a fault in the resolver excitation signal provided to the second resolver control circuit. The systems and methods described herein can also be configured to double the gain of the first resolver amplifier using the first resolver control circuit in response to receiving an indication from the first resolver control circuit via a communication bus between the first and second resolver control circuits that the second resolver control circuit is set to a neutral voltage.

[0039] In some embodiments, the systems and methods described herein can be configured to fix the first resolver control circuit to a neutral voltage in response to a first resolver control circuit detecting a fault in the resolver excitation signal provided to the first resolver control circuit and in response to a second resolver control circuit detecting a fault in the resolver excitation signal provided to the second resolver control circuit. The systems and methods described herein can also be configured to double the gain of a second resolver amplifier using a second resolver control circuit in response to setting the first resolver control circuit to a neutral voltage.

[0040] In some embodiments, the systems and methods described herein can be configured to generate a resolver excitation signal. The systems and methods described herein can be configured to provide the resolver excitation signal to inputs of a first resolver control circuit and a second resolver control circuit. In some embodiments, the first resolver control circuit is independent of the second resolver control circuit. In some embodiments, the first resolver control circuit is disposed on a first silicon element, and the second resolver control circuit is disposed on a second element separate from the first silicon element.

[0041] In some embodiments, the systems and methods described herein can be configured to, in response to a first resolver control circuit detecting a fault in the resolver excitation signal provided to the first resolver control circuit, bias a first resolver amplifier using the first resolver control circuit, and transmit an indication, via a communication bus between the first and second resolver control circuits, that the first resolver control circuit detected a fault in the resolver excitation signal provided to the first resolver control circuit. In some embodiments, biasing the first resolver amplifier and / or the second resolver amplifier may include fixing the first resolver amplifier and / or the second resolver amplifier to a neutral voltage.

[0042] The system and method described herein can be configured to, in response to a first resolver control circuit not detecting a fault in the resolver excitation signal provided to the first resolver control circuit, set a first switch of the first resolver control circuit to a first position. The system and method described herein can also be configured to, in response to the first switch being set to the first position, provide the resolver excitation signal provided to the first resolver control circuit to the first resolver amplifier.

[0043] The system and method described herein can be configured to, in response to a second resolver control circuit detecting a fault in the resolver excitation signal provided to the second resolver control circuit and in response to receiving, via a communication bus, an indication from the second resolver control circuit that a first resolver control circuit has detected a fault in the resolver excitation signal provided to the first resolver control circuit, wherein: (i) a second switch of the second resolver control circuit is set from a first position to a second position; (ii) the gain of the second resolver amplifier is doubled using the second resolver control circuit; (iii) a second output signal is provided to the second resolver amplifier via the second switch, the second output signal having an output frequency and amplitude associated with a desired resolver excitation signal corresponding to the resolver excitation signal provided to the second resolver control circuit; and (iv) an indication from the second resolver control circuit that the second resolver control circuit has detected a fault in the resolver excitation signal provided to the second resolver control circuit is transmitted to the first resolver control circuit via the communication bus between the first and second resolver control circuits.

[0044] The system and method described herein can be configured to, in response to the second resolver control circuit not detecting a fault in the resolver excitation signal provided to the second resolver control circuit, set a second switch of the second resolver control circuit to a first position. The system and method described herein can also be configured to, in response to the second switch being set to the first position, provide the resolver excitation signal provided to the second resolver control circuit to the second resolver amplifier.

[0045] The system and method described herein can be configured to double the gain of a second resolver amplifier in response to receiving an indication from a second resolver control circuit via a communication bus between the first and second resolver control circuits that the first resolver control circuit has detected a fault in the resolver excitation signal provided to the first resolver control circuit.

[0046] The system and method described herein can be configured to, in response to a second resolver control circuit receiving an indication via a communication bus between the first and second resolver control circuits that the first resolver control circuit has detected a fault in the resolver excitation signal provided to the first resolver control circuit, and in response to the second resolver control circuit not detecting a fault in the resolver excitation signal provided to the second resolver control circuit, double the gain of the second resolver amplifier using the second resolver control circuit, and provide the resolver excitation signal provided to the second resolver control circuit to the second resolver amplifier via a second switch of the second resolver control circuit in a first position.

[0047] The system and method described herein can be configured to, in response to a second resolver control circuit detecting a fault in the resolver excitation signal provided to the second resolver control circuit and in response to the absence of a fault in the resolver excitation signal provided to the first resolver control circuit, use the second resolver control circuit to bias the second resolver amplifier and transmit an indication to the first resolver control circuit via a communication bus between the first and second resolver control circuits that the second resolver control circuit has detected a fault in the resolver excitation signal provided to the second resolver control circuit.

[0048] The system and method described herein can be configured to, in response to receiving from the second resolver control circuit via a communication bus between the first resolver control circuit and the second resolver control circuit an indication that the second resolver control circuit has detected a fault in the resolver excitation signal provided to the second resolver control circuit, double the gain of the first resolver amplifier using the first resolver control circuit, and provide the resolver excitation signal provided to the first resolver amplifier via a first switch of the first resolver control circuit in a first position.

[0049] Figure 1 A vehicle 10 is generally illustrated according to the principles of this disclosure. Vehicle 10 may include any suitable vehicle, such as a sedan, truck, SUV, minivan, crossover, any other passenger vehicle, any suitable commercial vehicle, or any other suitable vehicle. While vehicle 10 is illustrated as a wheeled passenger vehicle intended for use on a road, the principles of this disclosure can be applied to other means of transport, such as an aircraft, ship, train, drone, or other suitable means of transport. Vehicle 10 includes a body 12 and a hood 14. A portion of the body 12 defines a passenger compartment 18. Another portion of the body 12 defines an engine compartment 20. The hood 14 is movably attached to a portion of the body 12 such that when the hood 14 is in a first position or open position, the hood 14 provides access to the engine compartment 20, and when the hood 14 is in a second position or closed position, the hood 14 covers the engine compartment 20.

[0050] The passenger compartment 18 is located behind the engine compartment 20. The vehicle 10 may include any suitable propulsion system, including: an internal combustion engine; one or more electric motors (e.g., an electric vehicle); one or more fuel cells; or a hybrid propulsion system (e.g., a hybrid vehicle) comprising a combination of an internal combustion engine, one or more electric motors, and / or any other suitable propulsion system. In some embodiments, the vehicle 10 may include a gasoline (petrol or gasoline) fuel engine, such as a spark-ignition engine. In some embodiments, the vehicle 10 may include a diesel fuel engine, such as a compression-ignition engine. The engine compartment 20 houses and / or encloses at least some components of the propulsion system of the vehicle 10. Additionally or alternatively, propulsion control devices, such as accelerator actuators (e.g., accelerator pedals), brake actuators (e.g., brake pedals), steering wheels, and other such components, are located in the passenger compartment 18 of the vehicle 10. The propulsion control devices may be actuated or controlled by the driver of the vehicle 10 and may be directly connected to corresponding components of the propulsion system, such as the accelerator, brakes, axles, vehicle transmission, etc. In some implementations, the propulsion control device can transmit signals to the vehicle computer (e.g., drive-by-wire), which in turn can control the corresponding propulsion components of the propulsion system.

[0051] In some embodiments, vehicle 10 includes a transmission communicated with the crankshaft via a flywheel, clutch, or hydraulic coupling. In some embodiments, the transmission includes a manual transmission. In some embodiments, the transmission includes an automatic transmission. Vehicle 10 may include one or more pistons that, in the case of an internal combustion engine or hybrid vehicle, cooperate with the crankshaft to generate forces that are transferred via the transmission to one or more shafts that rotate the wheels 22. When vehicle 10 includes one or more electric motors, a vehicle battery and / or fuel cell provide energy to the electric motors to rotate the wheels 22. In the case where vehicle 10 includes a vehicle battery that provides energy to one or more electric motors, when the battery is depleted, the vehicle can be connected to the power grid (e.g., using a wall socket) to recharge the battery cells. Alternatively or concurrently, vehicle 10 may employ regenerative braking, which uses one or more of the vehicle 10's electric motors as generators to convert kinetic energy lost due to deceleration back into energy stored in the battery.

[0052] Vehicle 10 may include an autonomous vehicle propulsion system, such as cruise control, adaptive cruise control, automatic braking control, other autonomous vehicle propulsion systems, or combinations thereof. Vehicle 10 may be an autonomous or semi-autonomous vehicle, or other suitable type of vehicle. Vehicle 10 may include more or fewer features than those generally illustrated and / or disclosed herein.

[0053] In some implementations, vehicle 10 may include a controller, such as controller 100, as... Figure 2 Generally as shown. Controller 100 may include any suitable controller, such as an electronic control unit or other suitable controller. Controller 100 may be configured to control various functions, such as those of vehicle 10. Controller 100 may include processor 102 and memory 104. Processor 102 may include any suitable processor, such as those described herein. Alternatively or additionally, controller 100 may include any suitable number of processors other than processor 102. Memory 104 may include a single disk or multiple disks (e.g., hard disk drive) and includes a storage management module that manages one or more partitions within memory 104. In some embodiments, memory 104 may include flash memory, semiconductor (solid-state) memory, etc. Memory 104 may include random access memory (RAM), read-only memory (ROM), or a combination thereof. Memory 104 may include instructions that, when executed by processor 102, cause processor 102 to control at least various aspects of vehicle 10.

[0054] In some implementations, the controller 100 may be configured to operate the fail-safe rotary transformer excitation system 200, such as Figure 3 As generally shown. For example, controller 100 may generate a resolver excitation signal for energizing resolver 222. The resolver may include any suitable resolver configured to provide a sine and / or cosine output, which may be used by controller 100 to detect or determine the speed and / or position of the associated motor (e.g., which may be used to control various aspects of vehicle 10).

[0055] The controller 100 can provide the rotary transformer excitation signal to the input terminals of the first rotary transformer control circuit 202 and the second rotary transformer control circuit 204. The first rotary transformer control circuit 202 can be independent of the second rotary transformer control circuit 204. In some embodiments, the first rotary transformer control circuit 202 can be disposed on the first silicon element, and the second rotary transformer control circuit 204 can be disposed on a second element separate from the first silicon element.

[0056] The first resolver control circuit 202 can be configured to detect faults in the system 200, such as faults in the resolver excitation signal or other suitable faults, such as those described herein. Alternatively, the second resolver control circuit 204 can be configured to detect faults in the system 200, such as faults in the resolver excitation signal or other suitable faults, such as those described herein.

[0057] In response to detecting a fault in the resolver excitation signal provided to the first resolver control circuit 202 or other suitable fault in system 200, the first resolver control circuit 202 may fix the first resolver amplifier 218 to the neutral voltage. The first resolver control circuit 202 may transmit information indicating that it has detected the fault and / or that it has been set to the neutral voltage to the second resolver control circuit 204 via the inter-amplifier communication bus 226. In response to receiving the information indicating that it has detected the fault and / or that it has been set to the neutral voltage, the second resolver control circuit 204 may use the second resolver control circuit to double the gain of the second resolver amplifier 220.

[0058] In some embodiments, in response to detecting a fault in the resolver excitation signal provided to the first resolver control circuit 202, the first resolver control circuit 202 can set the first switch 210 from a first position to a second position. The first resolver control circuit 202 can provide a first output signal with an output frequency and amplitude programmed in memory to the first resolver amplifier 218 via the first switch 210.

[0059] In some embodiments, the first resolver control circuit 202 can set the first switch 210 to a first position before detecting a fault in the resolver excitation signal provided to the first resolver control circuit. In response to the first switch 210 being set to the first position, the first resolver control circuit 202 can provide the resolver excitation signal provided to the first resolver amplifier 218.

[0060] In some embodiments, in response to detecting a fault in the resolver excitation signal provided to the second resolver control circuit 204 or other suitable fault in system 200, and in response to receiving information indicating a fault in the first resolver control circuit 202 and / or that the first resolver amplifier 218 is fixed to the median voltage, the second resolver control circuit 204 may double the gain of the second resolver amplifier 220 and may set the second switch 212 from a first position to a second position. For example, before the second resolver control circuit 204 detects a fault in the resolver excitation signal provided to the second resolver control circuit 204, the second resolver control circuit 204 may set the second switch 212 to the first position, which allows the resolver excitation signal provided to the second resolver control circuit 204 to be supplied to the second resolver amplifier 220.

[0061] In response to setting the second switch 212 to the second position, the second resolver control circuit 204 can provide a second output signal to the second resolver amplifier 220 via the second switch 212. This second output signal has an output frequency and amplitude programmed in local memory. In some embodiments, an internal resolver exciter waveform generator 216 associated with the second resolver control circuit 204 can be configured to generate a second output signal having an output frequency and amplitude programmed in local memory and associated with a desired resolver excitation signal (e.g., it may include a resolver excitation signal programmed into the memory of the internal resolver exciter waveform generator 216 and corresponding to a resolver excitation signal provided by the controller 100 or other suitable resolver excitation signal).

[0062] In some embodiments, in response to a detected fault and in response to the absence of a fault in the first resolver control circuit 202, the second resolver control circuit 204 may fix the second resolver amplifier 220 to a neutral voltage. The second resolver control circuit 204 may transmit information indicating that it has detected the fault and / or that the second resolver amplifier 220 is set to a neutral voltage to the first resolver control circuit 202 via the inter-amplifier communication bus 226. In response to receiving information indicating that the second resolver control circuit 204 has detected the fault and / or that the second resolver amplifier 220 is set to a neutral voltage, the first resolver control circuit 202 may double the gain of the first resolver amplifier 218.

[0063] In some embodiments, controller 100 and / or system 200 may perform the methods described herein. However, the methods performed by controller 100 and / or system 200 described herein are not intended to be limiting, and any type of software executing on a controller or processor may perform the methods described herein without departing from the scope of this disclosure. For example, a controller such as a processor executing software within a computing device may perform the methods described herein.

[0064] Figure 4 This is a flowchart illustrating a fail-safe rotary transformer excitation method 300 based on the principles of this disclosure. At 302, method 300 generates a rotary transformer excitation signal. For example, controller 100 can generate the rotary transformer excitation signal.

[0065] In step 304, method 300 provides the resolver excitation signal to the input terminals of the first resolver control circuit and the second resolver control circuit. For example, controller 100 can provide the resolver excitation signal to the input terminals of the first resolver control circuit 202 and the second resolver control circuit 204.

[0066] In step 306, method 300, in response to a first resolver control circuit detecting a fault in the resolver excitation signal provided to the first resolver control circuit, uses the first resolver control circuit to bias a first resolver amplifier and transmits an indication that the first resolver control circuit detected a fault in the resolver excitation signal provided to the first resolver control circuit to the second resolver control circuit via a communication bus between the first and second resolver control circuits. For example, in response to detecting a fault in the resolver excitation signal provided to the first resolver control circuit 202, the first resolver control circuit 202 may bias a first resolver amplifier 218 and may transmit an indication that the first resolver control circuit 202 detected a fault in the resolver excitation signal provided to the first resolver control circuit 202 to the second resolver control circuit 204 via an inter-amplifier communication bus 226.

[0067] In some embodiments, a method for exciting a fail-safe rotary transformer includes: generating a rotary transformer excitation signal; providing the rotary transformer excitation signal to an input of a first rotary transformer control circuit and an input of a second rotary transformer control circuit; and in response to the first rotary transformer control circuit detecting a fault in the rotary transformer excitation signal provided to the first rotary transformer control circuit, setting a first switch of the first rotary transformer control circuit from a first position to a second position; and providing a first output signal via the first switch to a first rotary transformer amplifier, the first output signal having an output frequency and amplitude corresponding to the rotary transformer excitation signal.

[0068] In some embodiments, the first resolver control circuit is independent of the second resolver control circuit. In some embodiments, the first resolver control circuit is disposed on a first silicon element, and the second resolver control circuit is disposed on a second element separate from the first silicon element. In some embodiments, the method further includes: setting the first switch to a first position before the first resolver control circuit detects a fault in the resolver excitation signal provided to the first resolver control circuit, wherein, in response to the first switch being set to the first position, the resolver excitation signal provided to the first resolver control circuit is provided to the first resolver amplifier. In some embodiments, the method further includes, in response to the second resolver control circuit detecting a fault in the resolver excitation signal provided to the second resolver control circuit, setting a second switch of the second resolver control circuit from a first position to a second position; and providing a second output signal via the second switch to the second resolver amplifier, the second output signal having an output frequency and amplitude corresponding to the resolver excitation signal. In some embodiments, the method further includes: setting the second switch to the first position before the second resolver control circuit detects a fault in the resolver excitation signal provided to the second resolver control circuit, wherein, in response to the second switch being set to the first position, the resolver excitation signal provided to the second resolver control circuit is provided to the second resolver amplifier. In some embodiments, the method further includes: fixing the first resolver control circuit to a neutral voltage in response to the first resolver control circuit detecting a fault in the resolver excitation signal provided to the first resolver control circuit. In some embodiments, the method further includes: doubling the gain of the second resolver amplifier using the second resolver control circuit in response to receiving an indication from the second resolver control circuit via a communication bus between the second resolver control circuit and the first resolver control circuit that the first resolver control circuit is set to a neutral voltage.

[0069] In some embodiments, a system for excitation of a fail-safe rotary transformer includes a controller having a processor and a memory, the memory including instructions that, when executed by the controller, cause the controller to: generate a rotary transformer excitation signal; and provide the rotary transformer excitation signal to inputs of a first rotary transformer control circuit and a second rotary transformer control circuit. In response to detecting a fault in the rotary transformer excitation signal provided to the first rotary transformer control circuit, the first rotary transformer control circuit: sets a first switch of the first rotary transformer control circuit from a first position to a second position; and provides a first output signal via the first switch to a first rotary transformer amplifier, the first output signal having an output frequency and amplitude corresponding to the rotary transformer excitation signal.

[0070] In some embodiments, the first resolver control circuit is independent of the second resolver control circuit. In some embodiments, the first resolver control circuit is disposed on a first silicon element, and the second resolver control circuit is disposed on a second element separate from the first silicon element. In some embodiments, before the first resolver control circuit detects a fault in the resolver excitation signal provided to the first resolver control circuit, the first resolver control circuit sets the first switch to a first position, and in response to the first switch being set to the first position, the first resolver control circuit provides the resolver excitation signal provided to the first resolver amplifier. In some embodiments, in response to the second resolver control circuit detecting a fault in the resolver excitation signal provided to the second resolver control circuit, the second resolver control circuit: sets a second switch of the second resolver control circuit from a first position to a second position; and provides a second output signal via the second switch to the second resolver amplifier, the second output signal having an output frequency and amplitude corresponding to the resolver excitation signal. In some embodiments, before the second resolver control circuit detects a fault in the resolver excitation signal provided to the second resolver control circuit, the second resolver control circuit sets the second switch to the first position, and in response to the second switch being set to the first position, the second resolver control circuit provides the resolver excitation signal provided to the second resolver control circuit to the second resolver amplifier. In some embodiments, in response to the first resolver control circuit detecting a fault in the resolver excitation signal provided to the first resolver control circuit, the first resolver control circuit fixes itself to a neutral voltage. In some embodiments, in response to receiving an indication from the second resolver control circuit via a communication bus between the first and second resolver control circuits that the first resolver control circuit is set to a neutral voltage, the second resolver control circuit uses itself to double the gain of the second resolver amplifier.

[0071] In some embodiments, an apparatus for exciting a fail-safe rotary transformer includes a controller configured to: generate a rotary transformer excitation signal; and provide the rotary transformer excitation signal to inputs of a first rotary transformer control circuit and a second rotary transformer control circuit. In response to detecting a fault in the rotary transformer excitation signal provided to the first rotary transformer control circuit, the first rotary transformer control circuit: sets a first switch of the first rotary transformer control circuit from a first position to a second position; and provides a first output signal via the first switch to a first rotary transformer amplifier, the first output signal having an output frequency and amplitude corresponding to the rotary transformer excitation signal. In response to detecting a fault in the rotary transformer excitation signal provided to the second rotary transformer control circuit, the second rotary transformer control circuit: sets a second switch of the second rotary transformer control circuit from a first position to a second position; and provides a second output signal via the second switch to a second rotary transformer amplifier, the second output signal having an output frequency and amplitude corresponding to the rotary transformer excitation signal.

[0072] In some embodiments, the first resolver control circuit is independent of the second resolver control circuit. In some embodiments, the first resolver control circuit is disposed on a first silicon element, and the second resolver control circuit is disposed on a second element separate from the first silicon element. In some embodiments, before the first resolver control circuit detects a fault in the resolver excitation signal provided to the first resolver control circuit, the first resolver control circuit sets the first switch to the first position, and in response to the first switch being set to the first position, the first resolver control circuit provides the resolver excitation signal provided to the first resolver amplifier.

[0073] In some embodiments, a method for exciting a fail-safe rotary transformer includes: generating a rotary transformer excitation signal; and providing the rotary transformer excitation signal to an input of a first rotary transformer control circuit and an input of a second rotary transformer control circuit. The method further includes, in response to the first rotary transformer control circuit detecting a fault in the rotary transformer excitation signal provided to the first rotary transformer control circuit, using the first rotary transformer control circuit to bias a first rotary transformer amplifier; and transmitting, via a communication bus between the first and second rotary transformer control circuits, an indication that the first rotary transformer control circuit detected a fault in the rotary transformer excitation signal provided to the first rotary transformer control circuit.

[0074] In some embodiments, the first resolver control circuit is independent of the second resolver control circuit. In some embodiments, the first resolver control circuit is disposed on a first silicon element, and the second resolver control circuit is disposed on a second element separate from the first silicon element. In some embodiments, the method further includes: in response to the first resolver control circuit not detecting a fault in the resolver excitation signal provided to the first resolver control circuit, setting a first switch of the first resolver control circuit to a first position, wherein, in response to the first switch being set to the first position, the resolver excitation signal provided to the first resolver control circuit is provided to the first resolver amplifier. In some embodiments, the method further includes, in response to the second resolver control circuit detecting a fault in the resolver excitation signal provided to the second resolver control circuit and in response to the second resolver control circuit receiving, via the communication bus, an indication that the first resolver control circuit detected a fault in the resolver excitation signal provided to the first resolver control circuit, thereby: setting a second switch of the second resolver control circuit from a first position to a second position; doubling the gain of the second resolver amplifier using the second resolver control circuit; providing a second output signal to the second resolver amplifier via the second switch, the second output signal having an output frequency and amplitude associated with a desired resolver excitation signal corresponding to the resolver excitation signal provided to the second resolver control circuit; and transmitting, via the communication bus between the first and second resolver control circuits, an indication that the second resolver control circuit detected a fault in the resolver excitation signal provided to the second resolver control circuit. In some embodiments, the method further includes: in response to the second resolver control circuit not detecting a fault in the resolver excitation signal provided to the second resolver control circuit, setting a second switch of the second resolver control circuit to a first position, wherein, in response to the second switch being set to the first position, the resolver excitation signal provided to the second resolver control circuit is provided to the second resolver amplifier.In some embodiments, the method further includes: in response to receiving, via the communication bus between the first and second resolver control circuits, an indication that the first resolver control circuit has detected a fault in the resolver excitation signal provided to the first resolver control circuit, doubling the gain of the second resolver amplifier using the second resolver control circuit. In some embodiments, the method further includes, in response to receiving via the communication bus between the first and second resolver control circuits an indication that the first resolver control circuit has detected a fault in the resolver excitation signal provided to the first resolver control circuit, and in response to the second resolver control circuit not detecting a fault in the resolver excitation signal provided to the second resolver control circuit, doubling the gain of the second resolver amplifier; and providing the resolver excitation signal provided to the second resolver control circuit to the second resolver amplifier via a second switch of the second resolver control circuit in a first position. In some embodiments, the method further includes, in response to the second resolver control circuit detecting a fault in the resolver excitation signal provided to the second resolver control circuit, and in response to the absence of a fault in the resolver excitation signal provided to the first resolver control circuit, using the second resolver control circuit to bias the second resolver amplifier; and transmitting to the first resolver control circuit via the communication bus between the first and second resolver control circuits an indication that the second resolver control circuit detected a fault in the resolver excitation signal provided to the second resolver control circuit. In some embodiments, the method further includes, in response to receiving from the second resolver control circuit via the communication bus between the first and second resolver control circuits an indication that the second resolver control circuit detected a fault in the resolver excitation signal provided to the second resolver control circuit, using the first resolver control circuit to double the gain of the first resolver amplifier; and providing the resolver excitation signal provided to the first resolver control circuit to the first resolver amplifier via a first switch of the first resolver control circuit in a first position. In some implementations, using the first resolver control circuit to bias the first resolver amplifier includes fixing the first resolver amplifier to a midpoint voltage.

[0075] In some embodiments, a system for excitation of a fail-safe rotary transformer includes a controller having a processor and a memory. The memory includes instructions that, when executed by the controller, cause the controller to: generate a rotary transformer excitation signal; and provide the rotary transformer excitation signal to inputs of a first rotary transformer control circuit and a second rotary transformer control circuit. The first rotary transformer control circuit is configured to, in response to detecting a fault in the rotary transformer excitation signal provided to the first rotary transformer control circuit,: bias a first rotary transformer amplifier; and transmit, via a communication bus between the first and second rotary transformer control circuits, an indication that the first rotary transformer control circuit has detected a fault in the rotary transformer excitation signal provided to the first rotary transformer control circuit.

[0076] In some embodiments, the first resolver control circuit is independent of the second resolver control circuit. In some embodiments, the first resolver control circuit is disposed on a first silicon element, and the second resolver control circuit is disposed on a second element separate from the first silicon element. In some embodiments, in response to the absence of a detected fault in the resolver excitation signal provided to the first resolver control circuit, the first resolver control circuit sets a first switch of the first resolver control circuit to a first position, wherein, in response to the first switch being set to the first position, the resolver excitation signal provided to the first resolver control circuit is provided to the first resolver amplifier. In some embodiments, the second resolver control circuit, in response to detecting a fault in the resolver excitation signal provided to the second resolver control circuit and in response to receiving an indication via the communication bus that the first resolver control circuit detected a fault in the resolver excitation signal provided to the first resolver control circuit, proceeds as follows: sets a second switch of the second resolver control circuit from a first position to a second position; doubles the gain of the second resolver amplifier using the second resolver control circuit; provides a second output signal to the second resolver amplifier via the second switch, the second output signal having an output frequency and amplitude associated with a desired resolver excitation signal corresponding to the resolver excitation signal provided to the second resolver control circuit; and transmits, via the communication bus between the first and second resolver control circuits, the indication that the second resolver control circuit detected a fault in the resolver excitation signal provided to the second resolver control circuit. In some embodiments, the second resolver control circuit, in response to the absence of a detected fault in the resolver excitation signal provided to the second resolver control circuit, sets a second switch of the second resolver control circuit to a first position, wherein, in response to the second switch being set to the first position, the resolver excitation signal provided to the second resolver control circuit is provided to the second resolver amplifier. In some embodiments, the second resolver control circuit, in response to receiving an indication via the communication bus between the first and second resolver control circuits that the first resolver control circuit has detected a fault in the resolver excitation signal provided to the first resolver control circuit, doubles the gain of the second resolver amplifier.In some embodiments, the second resolver control circuit, in response to receiving an indication via the communication bus between the first and second resolver control circuits that the first resolver control circuit detected a fault in the resolver excitation signal provided to the first resolver control circuit, and in response to no fault being detected in the resolver excitation signal provided to the second resolver control circuit, doubles the gain of the second resolver amplifier using the second resolver control circuit; and provides the resolver excitation signal provided to the second resolver control circuit to the second resolver amplifier via a second switch in a first position of the second resolver control circuit. In some embodiments, the second resolver control circuit, in response to detecting a fault in the resolver excitation signal provided to the second resolver control circuit, and in response to no fault being detected in the resolver excitation signal provided to the first resolver control circuit, biases the second resolver amplifier; and transmits an indication via the communication bus between the first and second resolver control circuits that the second resolver control circuit detected a fault in the resolver excitation signal provided to the second resolver control circuit.

[0077] The foregoing discussion is intended to illustrate the principles and various implementations of this disclosure. Once the foregoing disclosure is fully understood, many variations and modifications will become apparent to those skilled in the art. The appended claims are intended to be construed as encompassing all such variations and modifications.

[0078] The word “example” is used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as an “example” is not necessarily to be construed as preferred or superior to other aspects or designs. Rather, the use of the word “example” is intended to present the concept in a concrete manner. As used in this application, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” That is, unless otherwise stated or clear from the context, “X comprises A or B” is intended to mean any natural inclusion. That is, if X comprises A; X comprises B; or X comprises A and B, then “X comprises A or B” is satisfied in any of the foregoing cases. Furthermore, the article “a” used in this application and the appended claims should generally be interpreted as meaning “one or more” unless otherwise stated or clearly pointed to from the context in the singular form. In addition, the use of the terms “implementation” or “one implementation” throughout does not imply the same implementation or mode of implementation unless such a description is given.

[0079] The systems, algorithms, methods, instructions, etc., described herein can be implemented in hardware, software, or any combination thereof. Hardware may include, for example, a computer, intellectual property (IP) core, application-specific integrated circuit (ASIC), programmable logic array, optical processor, programmable logic controller, microcode, microcontroller, server, microprocessor, digital signal processor, or any other suitable circuit. In the claims, the term "processor" should be understood to include any of the foregoing hardware, whether alone or in combination. The terms "signal" and "data" are used interchangeably.

[0080] As used herein, the term "module" can include a packaged functional hardware unit designed for use with other components, an instruction set executable by a controller (e.g., a processor executing software or firmware), processing circuitry configured to perform a specific function, and a separate hardware or software component connected to a larger system. For example, a module can include application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), circuits, digital logic circuits, analog circuits, combinations of discrete circuits, gates, and other types of hardware or combinations thereof. In other embodiments, a module can include a memory storing instructions that can be executed by a controller to implement the features of the module.

[0081] Furthermore, in one aspect, for example, the system described herein may be implemented using a general-purpose computer or general-purpose processor with a computer program that, when executed, performs any of the corresponding methods, algorithms, and / or instructions described herein. Alternatively or alternatively, for example, a special-purpose computer / processor may be used, which may contain additional hardware for performing any of the methods, algorithms, or instructions described herein.

[0082] Furthermore, all or part of the embodiments of this disclosure may take the form of a computer program product accessible from, for example, a computer-usable or computer-readable medium. A computer-usable or computer-readable medium may be, for example, any means that can tangibly contain, store, transmit, or transport a program for use by or in conjunction with any processor. Such a medium may be, for example, an electronic, magnetic, optical, electromagnetic, or semiconductor device. Other suitable media are also available.

[0083] The above-described embodiments, implementations, and aspects have been provided to facilitate an easy understanding of this disclosure and do not limit it. Rather, this disclosure is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims, and this scope should be interpreted in the broadest possible sense to cover all such modifications and equivalent structures permitted by law.

Claims

1. A method for exciting a fail-safe rotary transformer, the method comprising the following steps: Generate excitation signal for the rotary transformer; The excitation signal of the rotary transformer is provided to the input terminal of the first rotary transformer control circuit and the input terminal of the second rotary transformer control circuit. In response to the first rotary transformer control circuit detecting a fault in the rotary transformer excitation signal provided to the first rotary transformer control circuit, and: The first resolver control circuit is used to bias the first resolver amplifier. and The communication bus between the first rotary transformer control circuit and the second rotary transformer control circuit transmits an indication to the second rotary transformer control circuit that the first rotary transformer control circuit has detected a fault in the rotary transformer excitation signal provided to the first rotary transformer control circuit. In response to the second rotary transformer control circuit receiving via the communication bus an indication that the first rotary transformer control circuit detected a fault in the rotary transformer excitation signal provided to the first rotary transformer control circuit, and in response to the second rotary transformer control circuit not detecting a fault in the rotary transformer excitation signal provided to the second rotary transformer control circuit, then: The gain of the second resolver amplifier is doubled using the second resolver control circuit; and The second switch of the second rotary transformer control circuit, which is in the first position, provides the rotary transformer excitation signal to the second rotary transformer amplifier.

2. The method according to claim 1, wherein, The first rotary transformer control circuit is independent of the second rotary transformer control circuit.

3. The method according to claim 2, wherein, The first rotary transformer control circuit is disposed on the first silicon element, and the second rotary transformer control circuit is disposed on a second element separate from the first silicon element.

4. The method according to claim 1, further comprising: In response to the first rotary transformer control circuit not detecting a fault in the rotary transformer excitation signal provided to the first rotary transformer control circuit, a first switch of the first rotary transformer control circuit is set to a first position, wherein, in response to the first switch being set to the first position, the rotary transformer excitation signal provided to the first rotary transformer control circuit is provided to the first rotary transformer amplifier.

5. The method according to claim 1, further comprising: In response to the second rotary transformer control circuit detecting a fault in the rotary transformer excitation signal provided to the second rotary transformer control circuit, and in response to the second rotary transformer control circuit receiving, via the communication bus, an indication that the first rotary transformer control circuit detected a fault in the rotary transformer excitation signal provided to the first rotary transformer control circuit, and: Set the second switch of the second rotary transformer control circuit from the first position to the second position; The gain of the second resolver amplifier is doubled using the second resolver control circuit; A second output signal is provided to the second resolver amplifier via the second switch. This second output signal has an output frequency and amplitude associated with a desired resolver excitation signal, which corresponds to the resolver excitation signal provided to the second resolver control circuit. The communication bus between the first and second rotary transformer control circuits transmits an indication to the first rotary transformer control circuit that the second rotary transformer control circuit has detected a fault in the rotary transformer excitation signal provided to the second rotary transformer control circuit.

6. The method according to claim 1, further comprising: In response to the second rotary transformer control circuit not detecting a fault in the rotary transformer excitation signal provided to the second rotary transformer control circuit, the second switch of the second rotary transformer control circuit is set to a first position, wherein, in response to the second switch being set to the first position, the rotary transformer excitation signal provided to the second rotary transformer control circuit is provided to the second rotary transformer amplifier.

7. The method according to claim 1, further comprising: In response to the second rotary transformer control circuit detecting a fault in the rotary transformer excitation signal provided to the second rotary transformer control circuit, and in response to the absence of a fault in the rotary transformer excitation signal provided to the first rotary transformer control circuit, then: The second resolver control circuit is used to bias the second resolver amplifier; and The communication bus between the first and second rotary transformer control circuits transmits an indication to the first rotary transformer control circuit that the second rotary transformer control circuit has detected a fault in the rotary transformer excitation signal provided to the second rotary transformer control circuit.

8. The method according to claim 1, further comprising: In response to receiving an indication from the second rotary transformer control circuit via the communication bus between the first rotary transformer control circuit and the second rotary transformer control circuit that the second rotary transformer control circuit has detected a fault in the rotary transformer excitation signal provided to the second rotary transformer control circuit, and: The gain of the first resolver amplifier is doubled using the first resolver control circuit; and The first switch of the first rotary transformer control circuit, which is in the first position, provides the rotary transformer excitation signal to the first rotary transformer amplifier.

9. The method according to claim 1, wherein, The step of using the first resolver control circuit to bias the first resolver amplifier includes fixing the first resolver amplifier to a midpoint voltage.

10. A system for exciting a fail-safe rotary transformer, the system comprising: A controller having a processor and a memory, the memory including instructions that, when executed by the controller, cause the controller to: Generate excitation signal for the rotary transformer; The excitation signal of the rotary transformer is provided to the input terminal of the first rotary transformer control circuit and the input terminal of the second rotary transformer control circuit. The first resolver control circuit is configured to, in response to detecting a fault in the resolver excitation signal provided to the first resolver control circuit, wherein: Biased first rotary transformer amplifier; and The communication bus between the first and second rotary transformer control circuits transmits an indication to the second rotary transformer control circuit that the first rotary transformer control circuit detected a fault in the rotary transformer excitation signal provided to the first rotary transformer control circuit. The first rotary transformer control circuit is further configured to, in response to the second rotary transformer control circuit receiving via the communication bus an indication that the first rotary transformer control circuit has detected a fault in the rotary transformer excitation signal provided to the first rotary transformer control circuit, and in response to the second rotary transformer control circuit not detecting a fault in the rotary transformer excitation signal provided to the second rotary transformer control circuit, wherein: The gain of the second resolver amplifier is doubled using the second resolver control circuit; and The second switch of the second rotary transformer control circuit, which is in the first position, provides the rotary transformer excitation signal to the second rotary transformer amplifier.

11. The system according to claim 10, wherein, The first rotary transformer control circuit is independent of the second rotary transformer control circuit.

12. The system according to claim 11, wherein, The first rotary transformer control circuit is disposed on the first silicon element, and the second rotary transformer control circuit is disposed on a second element separate from the first silicon element.

13. The system according to claim 10, wherein, In response to the absence of a fault detected in the rotary transformer excitation signal provided to the first rotary transformer control circuit, the first switch of the first rotary transformer control circuit is set to a first position, wherein, in response to the first switch being set to the first position, the rotary transformer excitation signal provided to the first rotary transformer control circuit is provided to the first rotary transformer amplifier.

14. The system according to claim 10, wherein, The second rotary transformer control circuit responds to detecting a fault in the rotary transformer excitation signal provided to the second rotary transformer control circuit, and responds to receiving an indication via the communication bus that the first rotary transformer control circuit detected a fault in the rotary transformer excitation signal provided to the first rotary transformer control circuit, wherein: Set the second switch of the second rotary transformer control circuit from the first position to the second position; The gain of the second resolver amplifier is doubled using the second resolver control circuit; A second output signal is provided to the second resolver amplifier via the second switch. This second output signal has an output frequency and amplitude associated with a desired resolver excitation signal, which corresponds to the resolver excitation signal provided to the second resolver control circuit. The communication bus between the first and second rotary transformer control circuits transmits an indication to the first rotary transformer control circuit that the second rotary transformer control circuit has detected a fault in the rotary transformer excitation signal provided to the second rotary transformer control circuit.

15. The system according to claim 10, wherein, In response to the absence of a fault detected in the rotary transformer excitation signal provided to the second rotary transformer control circuit, the second switch of the second rotary transformer control circuit is set to a first position, wherein, in response to the second switch being set to the first position, the rotary transformer excitation signal provided to the second rotary transformer control circuit is provided to the second rotary transformer amplifier.

16. The system according to claim 10, wherein, The second rotary transformer control circuit responds to detecting a fault in the rotary transformer excitation signal provided to the second rotary transformer control circuit, and responds to the absence of a fault in the rotary transformer excitation signal provided to the first rotary transformer control circuit, wherein: Biased second rotary transformer amplifier; and The communication bus between the first and second rotary transformer control circuits transmits an indication to the first rotary transformer control circuit that the second rotary transformer control circuit has detected a fault in the rotary transformer excitation signal provided to the second rotary transformer control circuit.

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