| Summary: | Hardware-in-the-Loop (HIL) test platform for planetary rovers was designed, fabricated and tested in
the present work. The ability for planetary rover designers and mission planners to estimate the rover’s
performance through software simulation is crucial. HIL testing can further the benefits of software
simulations by allowing designers to incorporate hardware components within traditionally pure software
simulations. This provides more accurate performance results without having access to all hardware
components, as would be required for a full prototype testing.
The test platform is designed with complete modularity such that different types of tests can be
performed for varying types of planetary rovers and in different environments. For demonstrating the
operation of the test platform, however, the power system operation of a solar powered rover was
examined. The system consists of solar panels, a solar charge controller, a battery, a DC/DC converter, a
DC motor and a flywheel. In addition, a lighting system was designed to simulate the solar radiation
conditions solar panels would experience throughout a typical day. On the software side, a library of
component models was developed within MapleSim and model parameters were tuned to match the
hardware on the test bench. A program was developed for real-time simulations within Labview allowing
communication between hardware components and software models. This program consists of all the
component models, hardware controls and data acquisitioning. The GUI of this program allows users to
select which component is to be tested and which component is to be simulated, change model parameters
as well as see real time sensor measurements for each component. A signal scaling technique based on
non-dimensionalization is also presented, which can be used in an HIL application for obtain scaling
factors to ensure dynamic similarity between two systems.
A demonstration of power estimation was performed using the pure software model simulations as
well as the pure hardware testing. Hardware components were then added into the software simulation
progressively with results showing better accuracy as hardware is added. The rover’s power flow was also
estimated under different load conditions and seasonal variation. These simulations clearly demonstrate
the effectiveness of an HIL platform for testing a rover’s hardware performance.
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