A method for monitoring property changes in a composite material structure includes: transmitting a radio-frequency (RF) signal towards the composite material structure using a millimeter-wave radar sensor embedded in the composite material structure; receiving a reflected signal from the composite material structure using the millimeter-wave radar sensor; processing the reflected signal; and determining a property change in the composite material structure based on processing the reflected signal.

A method of controlling an active aerodynamic system of a vehicle includes calculating a first spring force estimated value from at least one sensed vehicle handling characteristic, and a second spring force estimated value from a nominal spring characteristic curve. When a difference between the first and second spring force estimated values is equal to or greater than a spring threshold value, a nominal spring characteristic curve is adjusted to define an adjusted spring characteristic curve, and the active aerodynamic system is controlled using the adjusted spring characteristic curve. When the difference between the first and second spring force estimated values is equal to or greater than the spring threshold value, a signal may also be engaged to provide a service recommendation.

A method for controlling a climate test chamber for conditioning air and a test chamber includes a fuel cell assembly exposed to at least one physical test condition in a test space. The fuel cell assembly includes at least one electrochemical fuel cell having an anode compartment and a cathode compartment each having a feed opening for introducing reactants and a discharge opening for discharging waste products of the fuel cell assembly. The fuel cell assembly is operated in the test space, and a fuel gas and an oxidation gas is fed to the fuel cell assembly as reactants. The test space is supplied with conditioned supply air and exhaust air is discharged from the test space by an air conditioning and ventilation system. An oxygen concentration is determined using a sensor and a controller controls the oxygen concentration.

A method of controlling an active aerodynamic system of a vehicle includes calculating a first spring force estimated value from at least one sensed vehicle handling characteristic, and a second spring force estimated value from a nominal spring characteristic curve. When a difference between the first and second spring force estimated values is equal to or greater than a spring threshold value, a nominal spring characteristic curve is adjusted to define an adjusted spring characteristic curve, and the active aerodynamic system is controlled using the adjusted spring characteristic curve. When the difference between the first and second spring force estimated values is equal to or greater than the spring threshold value, a signal may also be engaged to provide a service recommendation.

A method for monitoring property changes in a composite material structure includes: transmitting a radio-frequency (RF) signal towards the composite material structure using a millimeter-wave radar sensor embedded in the composite material structure; receiving a reflected signal from the composite material structure using the millimeter-wave radar sensor; processing the reflected signal; and determining a property change in the composite material structure based on processing the reflected signal.