Travel Reduction Control of Distributed Drive Electric Agricultural Vehicles Based on Multi-Information Fusion

In agricultural vehicles with internal combustion engines, owing to the use of rear-wheel drive or four-wheel drive, it is difficult to obtain information regarding the slip of the driving wheels. Excessive wheel slip, an inevitable phenomenon occurring during agricultural activities, can easily damage the original soil surface and result in excessive energy consumption. To solve these problems, a distributed drive agricultural vehicle (DDAV) based on multi-information fusion was proposed. The actual travel reduction of each wheel was calculated by determining the vehicle parameters in order to deliver the required torque to the four drive wheels via sliding mode control (SMC) and incremental proportional-integral (PI) control. Through this process, the vehicle always operates in a straight line. Test results show that, on a uniform surface, the travel reduction of each wheel can be maintained at the target value by using the incremental PI control strategy, with only minor fluctuations, to make the vehicle run in a straight line (R2 = 0.9999). Furthermore, on a separated surface, the travel reduction of each wheel can be maintained at the target value, and using the SMC strategy enables more identical coefficient of gross tractions for each wheel to make the vehicle run in a straight line (R2 = 0.9902). Unlike the non-control strategy, the vehicle reaches a stable state within 1 s, owing to the use of a controller that can effectively reduce the impact of road changes on vehicle velocity. This study can provide a reference for the drive control of DDAVs.

Methodology for choosing a propulsion device for special-purpose vehicles

The ability to move on different types of soils is one of the main indicators of the efficiency of mobile vehicles in off-road conditions. The movement of such special mobile machines is carried out due to the interaction of the propulsion with the support surface. Therefore, significant reserves to increase productivity and reduce the cost of technological and transport works are laid in reducing energy consumption when the engine interacts with the surface. On the process of interaction of the wheel drive with the deformable support surface it is established that the parameters of this interaction depend on a number of factors: normal load, angular velocity and torque. In the General case, the parameters of interaction of each engine change when changing the mode of movement of the wheeled vehicle, and the ability to change the air pressure in the tires when driving on different support surfaces allows to increase the performance of the wheeled vehicle In the study of the caterpillar, it was found that the pitch of the caterpillar, the stiffness of the caterpillar, the angular stiffness of two adjacent tracks, reducing the pitch of the caterpillar chain, reducing the stiffness of the caterpillar, increasing the angular stiffness of two adjacent tracks, affect the efficiency of the machine. The scientific novelty of the study is to develop a method of choosing the engine of a special mobile machine that works off-road, in the process of its design. Wheel or crawler solutions will mainly determine the performance and efficiency of special purpose vehicles. The choice of engine for special mobile machines is based on a set of criteria. The criteria determine the importance of the implementation of the tasks in relation to the efficiency of functioning. Knowing the sowing capacity of the soil, and taking into account the possibility of movement of a particular special mobile machine depending on the type of soil, you can choose one or another type of engine.

A Finite-Time Speed and Direction Control for Four-Wheel Drive System

With the rapid use of the Four-Wheel Drive System (FWDS) worldwide, the necessity of having an adequate control system to control speed and direction in FWDS is extremely required. For this purpose, several control schemes are available in the literature to control the speed and direction in FWDS which should be fast convergence of the control, continuous control performance, and solving external disturbances. In latest years, finite-time controllers (FTC) have gained more consideration from many researchers in the control area, who have expressed applications in several procedures and systems. This research provides a major review of the FTC approaches via both input and output feedbacks for controlling FWDS.

Phase Portrait Trajectory of a 3DOF Vehicular Dynamic Model

This article formulates a front-wheel-drive three-degree-of-freedom (3DOF) four-wheel planar vehicle model with the Magic Formula tire model. The state variables' evolutions of the model, i.e., trajectories of the model under acceleration and deacceleration conditions, are analyzed. The process of evolution is divided into desirable and undesirable phases based on the response characteristics of the vehicle to the driver input during the process. The trajectories are categorized as unsaturated trajectories and saturated trajectories by the existence of saturated tires during these phases. The response of state variables to driver input under acceleration conditions during undesirable phases are zero or even opposite, while the response of undesirable phases under the deacceleration condition is partially positive. Besides, the existing yaw rate safety envelope is recalibrated by using a longitudinal and lateral tire force coupling model. A more accurate yaw rate safety envelope is obtained from the given driver input. Furthermore, a longitudinal speed safety envelope is proposed according to the relationships among slip angle, yaw rate, and longitudinal speed. These safety envelopes are determined by driver input, tire properties, and grip condition. After overlaying yaw rate and longitudinal speed safety envelopes in the state space, the feasibility of using the safety envelope as trajectory classification criteria is discussed.

Designing and performance investigation of permanent magnet motor prototype for UTV electric drive train application

<span lang="EN-US">The dynamic design specifications of a vehicle are used to define the required torque and speed of a permanent magnet motor. This is due to providing clear instructions on the intent, performance, and construction of a vehicle. Therefore, this study aims to determine an engineering design and prototyping process of a Permanent Magnet Motor, to be used as an electric powertrain in a Utility Vehicle. Based on being used in severe road condition (steep inclination and off road), the vehicle should be able to handle a 45° inclination with total payload of approximately 250 kg. Using a rear-wheel-drive traction, its weight should also be less than 1000 kg. Furthermore, the motor should be operated at a maximum battery voltage of 100 V. According to the requirements, the electric powertrain should further have the ability to deliver a torque of approximately 1600 Nm on both rear wheels. Using a finite element method to simulate performances, transmission was coupled to the motor in providing the required torque. In addition, the motor prototype was subsequently manufactured and tested using a dynamometer. The results showed that the motor produced 19.6 kW, 5600 RPM, and 75 Nm at 96 V. Therefore, the design and prototyping process of the motor satisfied all the required specification.</span>

METHODS FOR ASSESSING THE TECHNICAL CONDITION OF BEARING HUBS IN MEANS OF TRANSPORT

This article presents two methods of testing bearing hubs, which may supplement the existing subjective and unreliable methods of diagnostics of rolling bearings used in wheel bearing hubs of motor vehicles and other means of road transport. One of the most important elements responsible for the safety of a vehicle is the bearing hub. Regular monitoring of the technical condition of bearings should become an obligation at vehicle inspection stations when carrying out a technical inspection of a vehicle, authorising it to travel on public roads. This article presents the results of vehicle tests with signs of damage to rolling bearings, using two test stands: one on which the dynamic balancer acted as a device for accelerating the wheel, and the other, which was designed as a test dedicated to automotive rolling bearings, where a dynamic weighbridge was used as the wheel drive, made it impossible to test the wheel at lower rotational speeds. The newly designed and manufactured bearing testing device eliminates the disadvantages of the previous stand, and additionally, enables the measurement of a fully loaded bearing hub, which enables the simulation of real operating conditions on the bearing hub.

Wheel drive with integrated differential

The performance indicators of wheeled arable machine-tractor units, which are accelerated on the working gear, depend on the operating modes of the wheels during this period. When the wheel is skidding, soil lumps break down in the contact spot, the soil structure is destroyed. Based on the system analysis of the wheels operation, the method of their improvement is justified by continuous control of the eccentric point of application of the driving torque and external load. As a result of the analysis for the first time, a soil-sparing wheel mover with the properties of a differential, a tangential force regulator and clearance regulator was developed. In the case of an eccentric application of a vertical load and a longitudinal pushing force, one of the satellites of the wheeled planetary gearbox is the leading and bearing one. The purpose of the article is to analyze the factors influencing the automatic adaptation of the wheel drive to changing operating conditions. It is established the relationship between the driving moment and the rolling resistance moment, the moments of inertia of the wheel and the drive gear of the integrated differential.

Kinematics and dynamics of an incomplete circular wheel drive of an agricultural tractor

The disadvantage of wheeled tractors is soil compaction, slipping due to limited traction, low tangential force. Experimental studies of a tractor with incomplete circular wheel mover on stubble, sand and virgin snow showed an increase in cross-country ability, a decrease in skidding, an increase in traction, and an increase in productivity. The purpose of the study is to develop a methodology for kinematic and dynamic analysis of incompletely rounded wheel propellers with a built-in differential. The equation of motion of the wheel is obtained on the basis of two-stage overcoming by the wheel of a single threshold obstacle taking into account the longitudinal and radial stiffness of the tire, its deformation, air resistance in the tire. The main influence is provided by translational speed, wheel radius and radial stiffness, the moment of inertia of the wheel and the shoulder of the application of mass. Planetary gearbox proposed in which the shaft of the driving satellite is a bearing, while the radius of the gear is an order of magnitude smaller than the radius of the wheel. The direction of improvement of wheel mover, increasing their traction properties is justified.