A novel assist-steering method with direct yaw moment for distributed-drive articulated heavy vehicle

Abstract

This paper presents a novel assist-steering method for distributed-drive articulated heavy vehicles (DAHVs) to reduce its dependency on hydraulic steering method and improve the pressure characteristics of hydraulic struts. The objective is to realise the electrification of steering process for DAHVs, which is the basis of unmanned design with more stable control in the following studies. The theory and purpose of the proposed assist-steering method in this paper distinguishes it from the traditional direct yaw-moment control method or assist-steering methods in the previous studies, which easily produce interference with hydraulic steering method in DAHVs during steering process. In this paper, an accurate vehicle model is developed along with the field test for its satisfactory verification. Meanwhile, with the decoupling analyses of two different effects of steering methods on vehicle steering process, the assist-steering method is developed. In order to show the advantages brought on by this method, a case study is performed and analyzed. The results demonstrate that this proposed method can reduce the pressure of hydraulic steering system to about 41.2% without any changes of steering process, which is limited by the drive ability of wheel-side motor. Moreover, the pressure of inlet chamber in hydraulic struts is always reduced to about 40%–60% without any changes of the pressure in outlet chamber, which can improve the working performance of hydraulic steering system.

Rollover Prevention Control for Autonomous Electric Road Sweeper

“…In the pure pursuit method, the steering angle or the articulation angle is only determined with P(x,y) and ρ. From Figure 6, the curvature κ of the circular arc connecting P(x,y) and the rear wheel is calculated as Equation (19). With the definition of κ, the reference articulation angle is calculated as Equation ( 20) [34].…”

“…In this type of vehicle, steering is achieved by changing the articulation angle using the hydraulic cylinder between the front and rear bodies. This type of steering has generally been adopted in construction machines such as wheel loaders, scrapers, loaders, and skidders [18,19]. Boschung's Urban-Sweeper S2.0 as well as the KIIT and AMSV's AERS have this type of a steering mechanism as well, i.e., AFS.…”

“…Moreover, this vehicle has rear-wheel drive with a single motor and a pneumatic braking system without an independent braking function. In other words, this vehicle has no differential braking or torque vectoring functions [18,19]. As such, it is impossible for one to apply yaw moment control with differential braking or torque vectoring in this vehicle.…”

Differential Drive Based Yaw Stabilization Using MPC for Distributed-Drive Articulated Heavy Vehicle

“…The vehicle is driven by all wheels with independent wheel-side motors. Its steering motion is realized with the coupling effect of hydraulic struts and articulation joint, which have been introduced in literature [3,17]. In terms of the traditional design of AHVs, there is no suspension in the chassis system.…”

“…The vehicle structure parameters used in the co-simulation can refer to the literature [3]. Due to the physical limitation of wheel-side motor, the output saturation issue is considered in the controller, and the maximal value of the direct yaw moment for the front and rear vehicle parts are all chosen as 146.7kNm (the maximum output torque of wheel-side motor is 2577Nm, the tyre effective radius is 1.032m, and the gear ratio is 25, which has been introduced in literature [17]). For the upper controller, including EKF and MPC algorithms, the gains are chosen according to the structure characteristics of DAHVs, which are shown in Table 2.…”