Remotely detected vehicle mass from engine torque-induced frame twisting
Abstract. Determining the mass of a vehicle from ground-based passive sensor data is important for many traffic safety requirements. This work presents a method for calculating the mass of a vehicle using ground-based video and acoustic measurements. By assuming that no energy is lost in the conversion, the mass of a vehicle can be calculated from the rotational energy generated by the vehicle’s engine and the linear acceleration of the vehicle over a period of time. The amount of rotational energy being output by the vehicle’s engine can be calculated from its torque and angular velocity. This model relates remotely observed, engine torque-induced frame twist to engine torque output using the vehicle’s suspension parameters and engine geometry. The angular velocity of the engine is extracted from the acoustic emission of the engine, and the linear acceleration of the vehicle is calculated by remotely observing the position of the vehicle over time. This method combines these three dynamic signals; engine induced-frame twist, engine angular velocity, and the vehicle’s linear acceleration, and three vehicle specific scalar parameters, into an expression that describes the mass of the vehicle. This method was tested on a semitrailer truck, and the results demonstrate a correlation of 97.7% between calculated and true vehicle mass.
Automotive transmission efficiency measurement using a chassis dynamometer
Automotive transmission efficiency measurements are usually performed on purpose-built rigs. A simple model was developed for calculating the overall transmission efficiency of passenger cars by using a chassis dynamometer. Wheel power and engine output were measured, and these values were used for calculations. The proposed method can only be employed for vehicles with manual drive because it requires constant speed measurements. Two case studies were investigated, with front-wheel and rear-wheel drive passenger cars. The results obtained from using the proposed model are in good agreement with data provided in the literature.
Effects of Heavy Truck Operations on Repair Costs of Low-Volume Highways
The economic impact of overweight permitted vehicles hauling sugar cane on Louisiana highways is evaluated. The highway routes that are used to haul this commodity are identified and statistical samples are selected and analyzed. Two different vehicle types and three different gross vehicle weights are chosen including 100,000-lb. and 120,000-lb. AASHTO design guidelines are used to determine the effects of heavy loads on pavements and bridges. The approach requires the overlay thickness needed to carry traffic from each gross vehicle weight for the design period and costs based on 20-year period. The state bridges are evaluated to satisfy regulations for the loading requirements and a fatigue cost is estimated for each safe crossing of a bridge. Results indicate that the damage from each FHWA Type 9, with a gross vehicle weight of 100,000-lb sugar cane load, to pavement and the bridge fatigue cost is at bout $5,500/year. Therefore, the current sugar cane trucks permit fee of $100 per vehicle per year is not adequate to recover these costs. It is recommended that the current 100,000-lb. gross vehicle weights be maintained, but the permit fees are increased, or the vehicle type is changed from a FHWA-Type-9 to a Type-10 vehicle. Under the second alternative, the permit fee can be reduced to zero and a tax incentive of $683 can be given to each truck for the conversion. Also, it is necessary to increase the highway funds to handle the extra damage caused by the increase of truck load limits.