Anyone with young children or grandchildren probably automatically thinks of a T-Rex or some other type of dinosaur, but in our case “dyno” is short for dynamometer. (Explain That Stuff has a great explanation of the different types and uses of dynos on their website, here.) In short, a dyno is a device that measures force, torque, or power by measuring rotational speed and force supplied by a motor or engine.
In August of this year, Lightning Hybrids acquired and installed a dynamometer custom-designed for our system (not to be confused with the chassis dyno used for emissions tests). When we connect our system to this machine we can test nearly any aspect of the system with essentially unlimited data acquisition capabilities and without being constrained by vehicle mounting and drivability.
In our case, we mount our hydraulic system to a driveshaft that interfaces with a water brake and then an electric rotor. As the system runs through cycles, the water brake applies a load to the driveshaft, which simulates friction from the road to the wheels, as a tachometer records RPM and the rotor measures the axial forces.
Its basic operation is the same as an engine dynamometer – common in the automotive industry – that controls the inputs and measures the power output from any generic engine. Similarly, our dynamometer controls the inputs and measures the outputs, but it is designed specifically to drive a standalone LH hydraulic hybrid system. This allows us to test nearly any aspect of the system with essentially unlimited data acquisition capabilities and without being constrained by vehicle mounting and drivability.
This dyno will be used for three types of testing: acceptance, development, and reliability testing. Several of our hydraulic systems have already completed rounds of acceptance testing, where we run the system on the dyno for a specified amount of time or equivalent distance and verify operability. Compared to on-vehicle acceptance testing, the dyno allows us to periodically check for and assess any fluid leaks before costly installation, wear in all the components with engineering-specified system inputs, and “drive” the system on a predefined route for much longer daily durations than are feasible for a vehicle driver. Along with running the tests faster, we can make vehicle-specific tweaks to the system more quickly.
The development testing is an exploratory role of the dyno for system prototypes. The flexibility of the dyno means that the system inputs can be anything the engineers deem pertinent. Development testing can identify issues before costly vehicle integration or direct a redesign before resources are spent on refining the prototype. It also can allow quick turnaround for iterations to the control system.
Reliability testing is a category LH has not yet been able to perform at the system level. For the first time, we can monitor component interactions and their effect on reliability throughout the lifespan of a system. With end-of-life considerations, we can even safely take the full system to failure. System failure on the dyno will have no environmental impact, we have a controlled environment for easier failure analysis, and failures are contained for easy repair.