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Contribution of dynamic vehicle loads to pavement failure
Published in Inge Hoff, Helge Mork, Rabbira Garba Saba, Eleventh International Conference on the Bearing Capacity of Roads, Railways and Airfields, Volume 2, 2022
To perform sample calculations of DALS, the data from weigh-in-motion were used. The WIM station is located on national road DK 22 (GPS coordinates 53.68499N, 17.42860E). The measurements were conducted from 1 January to 14 October 2014 (286 days). Data delivered from 141 448 commercial vehicles were used. Data were verified in order to filter invalid records and were processed to minimize the effect of systematic and random error (D. Rys, 2019; Dawid Rys & Burnos, 2021). Figure 5 presents Static Axle Load Spectra SALS, which were obtained on the basis of WIM data, as well as Dynamic Axle Load Spectra DALS, which were calculated according to equation (4). SALS were determined for six groups of axles: 1) front single axle(steering axle of the vehicle), 2) second single axle (which is a drive axle), 3) all remaining single axles in trailers, 4) tandem axles in trucks (both steering and drive), 5) tandem axles in trailers, and 6) tridem axles, which are found only in semi-trailers. In order to further simplify the analysis, ALS were determined without distinguishing between particular vehicle classes. Due to this fact, the shape of ALS of single axles includes several “peaks”. The first peaks correspond to the group of lighter commercial vehicles (e.g. 2-axle single-truck units), peaks shifted towards heavier loads correspond to articulated trucks with trailer or semi-trailer. Triple axles occur only in the group of heavy articulated trucks with semi-trailer. Two peaks which are observed in ALS of triple axles correspond to empty and optimally loaded vehicles, respectively.
What Is Intermodal Freight Transport?
Published in Lowe FCILT David, Intermodal Freight Transport, 2006
For readers unfamiliar with the technicalities of road vehicles, an articulated vehicle is one comprising a towing vehicle, correctly called the tractive unit, but often referred to as the cab or towing unit or incorrectly as the tractor unit, and a load-carrying trailer, the semi-trailer. They are hitched together with the front end of the semi-trailer superimposed on the rear of the tractive unit (transferring at least 20 per cent of the weight of the load carried by the semi-trailer onto the drawing vehicle, to meet legal requirements), being attached by means of a kingpin on the semi-trailer engaging in a ‘fifth-wheel’ turntable on the tractive unit. When detached from the tractive unit a semi-trailer is supported on forward-mounted landing legs (or landing gear) that are raised or folded away for travel.
Articulation angle estimation and control for reversing articulated vehicles
Published in Johannes Edelmann, Manfred Plöchl, Peter E. Pfeffer, Advanced Vehicle Control AVEC’16, 2017
In this paper, a steering control system is proposed for reversing semi-trailer trucks without using the articulation angle sensor. The proposed system consists of two main algorithms. First, the articulation angle estimation algorithm is designed based on the articulation dynamics model and the Kalman filter is applied to obtain the accurate articulation angle information. Secondly, the steering angle control algorithm for the semi-trailer tractor is designed based on the articulated vehicle kinematic model. The MPC (Model Predictive Control) method is utilized to calculate the proper steer angle such that both the tractor and the trailer follow the given path without departing from the road boundary. The structure of the proposed control system is illustrated in Figure 1.
A deep reinforcement learning-based optimization method for vibration suppression of articulated robots
Published in Engineering Optimization, 2023
Tie Zhang, Hubo Chu, Yanbiao Zou, Tao Liu
Articulated robots play a significant role in the industrial manufacturing field owing to their compact structure, wide working range and strong adaptability. However, the joint flexibility and coupling of articulated robots usually cause long-term vibration after movement, which seriously reduces positioning accuracy and work efficiency. As a feedforward method for suppressing residual vibration, input shaping technology (Singhose 2009) has attracted extensive attention and research. Early input shaping technology includes the zero-vibration (ZV) shaper (Singer and Seering 1990) and optimal arbitrary delay filter (Magee and Book 1998). Since the vibration-suppression effect of the above technology relies excessively on vibration mode accuracy, researchers have investigated a series of robust shapers, such as zero-vibration derivative (ZVD), zero-vibration derivative-derivative (ZVDD), extra-insensitive (EI), multi-bump EI and specified-insensitivity (SI) shapers (Vaughan, Yano, and Singhose 2008). However, the vibration mode of the articulated robot varies significantly with configuration, running speed and other factors. Simply improving the robustness of the shaper may fail to suppress the residual vibration effectively.
Optimal and Robust Control of Multi DOF Robotic Manipulator: Design and Hardware Realization
Published in Cybernetics and Systems, 2018
Syed Ali Ajwad, Jamshed Iqbal, Raza Ul Islam, Ahmed Alsheikhy, Abdullah Almeshal, Adeel Mehmood
Articulated robotic arms are the most common types of robots deployed in industrial processes (Manzoor et al. 2014). These robots usually resemble human arm in mechanical shape and kinematic configuration. However, they are more powerful, strong and fast. Precise and accurate operations of such arms demand a sophisticated and well-defined control strategy. In fact, the stability, precision, repeatability and throughput of a robotic arm can only be obtained with a complex and nonlinear control law. Furthermore, the robot operations should be safe and harmless as they may be deployed in close vicinity of human. The control means to formulate input torques so as to force the actuator to precisely follow a specified trajectory.
Development of a folding arm on an articulated mobile robot for plant disaster prevention
Published in Advanced Robotics, 2020
Nobutaka Matsumoto, Motoyasu Tanaka, Mizuki Nakajima, Masahiro Fujita, Kenjiro Tadakuma
Articulated mobile robots have many links serially connected by joints and can move on rough terrain, pass through narrow spaces, and move along the inside or outside of piping. Thus, many articulated mobile robots have been developed for search and rescue operations [1–5], in-pipe inspections [6–13], and inspection tasks inside nuclear reactors [14, 15].