High speed PXI resolver simulation modules for automotive

Addressing the increasing demand for precise and reliable testing of advanced servo systems, Pickering Interfaces has expanded its PXI and PXIe resolver simulator modules to include high-speed resolver simulation up to 130k RPM rotation. This development comes as higher speed resolver simulation has become crucial for modern control systems used in automotive designs, with excitation frequencies reaching up to 80 kHz. The goal is to enhance signal bandwidth, reduce noise susceptibility, and improve dynamic response. Testing embedded software with lower speed resolver simulations may lead to lower fidelity and missed software bugs.

The updated 41-670 PXI and 43-670 PXIe modules are designed to enable the simulation of multiple resolver pole pairs. While most electromechanical resolvers typically have a maximum rotational speed of 20k RPM when simulating, for example, four pole pairs, the corresponding x4 factor means this becomes 80k RPM electrical cycles to simulate. This enhancement caters to the need for more accurate and efficient testing methodologies in the realm of servo systems.

Stephen Jenkins, Simulation Product Manager at Pickering Interfaces, highlighted the unique approach taken by the company in developing these resolver simulators. “Rather than rely on FPGA approximations, our updated family of resolver simulators use actual transformers on board,” Jenkins explained. This approach ensures that the modules deliver precise, real-world analog signals with high-resolution angle simulation, guaranteeing reliable performance even at the highest speeds.

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The modules are versatile and can be used to simulate variable differential transformers (VDT), including both linear (LVDT) and rotary (RVDT) types, as well as resolvers with high-speed simulation up to 130k RPM rotation. With two (41/43-670-303) or four (41/43-670-301) banks, each capable of simulating the output of a single 5- or 6-wire VDT or resolver, or dual 4-wire utilizing a shared excitation signal, the modules offer flexibility in testing various configurations.

Moreover, the PXI high-channel density feature allows for the testing of multiple resolver channels in a compact footprint. The addition of built-in relays in the 41/43-670 modules further enhances their functionality by providing short or open circuits for each channel’s inputs and outputs. This reduces the need for external switching for fault insertion requirements, streamlining the testing process and improving efficiency. Additionally, the programmable phase delay feature can be utilized for simulating imperfect sensors and cabling, artificially offsetting single or multiple outputs for comprehensive testing scenarios.