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.
A New Adaptive Mass Estimation Approach of Heavy Truck Based on Engine Torque Local Convex Minimum Characteristic at Low Speeds
This paper proposes a new mass estimation for a vehicle system, utilizing the characteristics of engine torque local convex minimum, where the mass can be estimated based on the driving forces and the longitudinal accelerations only. Fundamentally, this approach generally requires no other information about an aerodynamic effect, a road grade, or a rolling friction, which is usually demanded by the existing well-known longitudinal dynamics and adaptive filter-based estimation methods. The effectiveness of the proposed approach was evaluated and validated by both TruckSim/Simulink co-simulation and actual field test data. It is found that the proposed estimation technique is more favorable for a situation where the vehicle is exposed to low-speed regions. In addition to this new mass estimation strategy, other new and current existing methods were explored and are reviewed here. Moreover, this study suggested a guideline for a hybrid-type mass estimation strategy to predict a mass by combining a new method with an existing one for every speed.
Provincial Highway Vehicle Weight Management Review and New Policy Development in Saskatchewan
Saskatchewan economy largely depends on bulk commodity export. With the changes in provincial economy and transportation patterns, there has been a significant increase in truck traffic and increasing demand for primary weight highways in rural Saskatchewan. Depending on truck configurations, typically the gross vehicle weight allowed for primary weight is approximately 15-20% higher than for secondary weight and the payload increase for primary weight is about 24-50%. Many Saskatchewan rural areas are only served by secondary weight highway, which is viewed as a competitive disadvantage. Higher vehicle weight will reduce freight transportation costs however it will also results in faster deterioration to the pavements. Saskatchewan Highways and Transportation conducted a comprehensive review on weight management and developed a new policy framework in 2006. This paper describes the details of the review and policy development, including problem identification, criteria development, costs and haul benefit analysis. The new policy makes the process of designating primary highways rational, transparent, and consistent. The paper also discussed some related difficult policy and technical issues.