Expectations for noise and vibration performance of personal vehicles such as golf carts, ATVs, and side-by-side vehicles continue to evolve, requiring additional efforts from manufacturers to meet customer expectations in comfort and the ability to converse with passengers.
As the marketplace for personal vehicles continues to grow, so does the need for additional refinements as manufacturers look for opportunities to differentiate their products from competitors. Noise and vibration performance has become a selling point, offering customers additional comfort and a sense of quality.
Currently, the golf cart market is comprised of two segments – electric- and petrol/gasoline-powered vehicles. The electric power train is very quiet in operation but costlier and more complex than its counterpart. Petrol-powered carts are cheaper and easier to maintain, but they are also significantly louder. In general, this cost-vs-NVH performance is leveraged in marketing quieter petrol-powered carts, touting them as the low-cost/same-performance alternative to electric.
While the problems generated by golf carts resemble those of other ground vehicles, the low speeds of golf carts means that most of the problems are power train related. This paper focuses on the power train source and describes the combined efforts of Brüel & Kjær Engineering Services and a golf cart manufacturer to identify opportunities within two different product types to improve the noise and vibration signature. The main goal was to reduce the overall sound pressure level as much as possible.
The most objectionable operating condition identified for further troubleshooting was the full-throttle start from standstill. For the operational data, baseline measurements on the golf cart were made outdoors in a parking lot, in a grass lot and up a grassy hill. As the NVH performance was similar for all operating conditions, the parking lot was chosen for ease of access. To evaluate potential countermeasures, the vehicle was operated on a hemi-anechoic chassis dynamometer to ensure repeatability. The investigations were used to identify design recommendations, providing the manufacturer with several opportunities to improve both product and customer experience.