Abstract: Apparatus and methods for controlling unmanned systems (UMSs), such as unmanned aircraft, are provided. A UMS can be provided that includes a physical computer, one or more auxiliary systems for the UMS, and a payload. The physical computer can execute software to cause the physical computer at least to instantiate a plurality of virtual computers that include a mission virtual computer and a payload virtual computer for: controlling the one or more auxiliary systems for the UMS using the mission virtual computer, communicating with the payload using the payload virtual computer, determining whether a software fault has occurred on one virtual computer of the plurality of virtual computers, and after determining that a software fault has occurred on one virtual computer of the plurality of virtual computers, preventing the software fault from causing a fault on a different virtual computer of the plurality of virtual computers.

Abstract: Apparatus and methods for controlling unmanned systems (UMSs), such as unmanned aircraft, are provided. A UMS can be provided that includes a physical computer, one or more auxiliary systems for the UMS, and a payload. The physical computer can execute software to cause the physical computer at least to instantiate a plurality of virtual computers that include a mission virtual computer and a payload virtual computer for: controlling the one or more auxiliary systems for the UMS using the mission virtual computer, communicating with the payload using the payload virtual computer, determining whether a software fault has occurred on one virtual computer of the plurality of virtual computers, and after determining that a software fault has occurred on one virtual computer of the plurality of virtual computers, preventing the software fault from causing a fault on a different virtual computer of the plurality of virtual computers.

Abstract: A digital sine wave may be converted to an analog signal at a digital to analog converter (DAC). The converted analog signal may be supplied to a device and an analog return signal from the device may be passed through a relaxed anti-aliasing filter and converted to digital code words at an analog to digital converter (ADC). An impedance may be calculated from the results of a Fourier analysis of the digital code words. The ADC and DAC clock frequencies may be asynchronous, independently variable, and have a greatest common factor of 1. The clock frequencies of the ADC and/or DAC may be adjusted to change a location of images in the ADC spectrum. By using these different, adjustable clock frequencies for the ADC and the DAC, an analog signal may have increased aliasing without introducing signal errors at a frequency of interest.

Abstract: A digital sine wave may be converted to an analog signal at a digital to analog converter (DAC). The converted analog signal may be supplied to a device and an analog return signal from the device may be passed through a relaxed anti-aliasing filter and converted to digital code words at an analog to digital converter (ADC). An impedance may be calculated from the results of a Fourier analysis of the digital code words. The ADC and DAC clock frequencies may be asynchronous, independently variable, and have a greatest common factor of 1. The clock frequencies of the ADC and/or DAC may be adjusted to change a location of images in the ADC spectrum. By using these different, adjustable clock frequencies for the ADC and the DAC, an analog signal may have increased aliasing without introducing signal errors at a frequency of interest.