Abstract: The fuel economy of wheel loaders is deeply affected by the efficiency of their propelling transmissions, however, the torque converter (TC) in existing propelling transmissions is a low-efficiency component and leads to excessive energy consumption. Accordingly, this paper replaces the TC with a hydrodynamic mechanical power split transmission (HMPST) for improving the fuel economy o...

A controller for a miniature wheel loader is developed to scoop rock piles autonomously. During a scooping task operation, the load of the bucket varies momentarily according to the phase of scooping. Before the insertion of the bucket into the rock pile, the load is just the bucket weight, but after the insertion the reaction force from the rock piles is applied to the bucket. The values of th...

We suggest that planning for automated earthmoving operations such as digging a foundation or leveling a mound of soil, be treated at multiple levels. In a system that we have developed, a coarse-level planner is used to tessellate the volume to be excavated into smaller pieces that are sequenced in order to complete the task efficiently. Each of the smaller volumes is treated with a refined pl...

The vibration control of a construction vehicle must be carried out in order to meet the aims of sustainable environmental development and to avoid the potential human health hazards. In this paper, based on market feedback, the driver seat vibration of a type of wheel loader in the left and right direction, is found to be significant over a certain speed range. In order to find abnormal vibrat...

Heavy duty powertrains are complex systems with components from various domains, different response times during transient operations and different efficient operating ranges. To ensure efficient transient operation of a powertrain, e.g. with low fuel consumption or short transient duration, it is important to come up with proper control strategies. In this dissertation, optimal control theory ...

The main purpose of this study is to review the cause for the crankshaft failure of six-cylinder diesel engine of a wheel loader after passing a short period of time. The failure had occurred after 4800 hours of in-service in the fifth crankpin of the crankshaft. Hardness and tensile tests were carried out to study their mechanical properties. Spectrophotometer machine was used to examine the c...

Wheel loaders are prone to lateral tilting accidents due to their complex working environment, variable structure frame and the large offset of the centroid position. The accidents may seriously threaten the driver’s safety. This paper proposes a steady-state margin (SSM) angle as a new instability threat indicator to analyse lateral stability of wheel loaders. Firstly, the structural character...

The transmissions of present heavy wheel loaders are in general based on torque converters. The characteristics of this component suits these machines, especially in that it enables thrust from zero vehicle speed without risk of stalling the engine, without active control. Unfortunately, the component also causes losses which might become large compared to the transmitted power. One approach fo...