Slip Calculation and Analysis for Four-wheel Drive Tractors

2005 ◽  
Vol 1 (1) ◽  
pp. 7-31 ◽  
Author(s):  
Márk Szente
Keyword(s):  
Rear Wheel ◽  
Front Wheel ◽  
Wheel Slip ◽  
Wheel Load ◽  
Low Profile ◽  
Wheel Drive ◽  
The Difference ◽  
Special Respect ◽  
Four Wheel Drive ◽  
Drawbar Pull

The objective of the research of tires was to determine the dynamic rolling radius and to apply it to wheel slip calculations with special respect to vertical wheel load and to tire inflation pressure. It is typical of mechanical four-wheel drive tractors that there is a definite additional power in the tractor power chain. This additional power is dependent on the difference between the front wheel and rear wheel peripheral speeds. Further-more, the purpose was to determine the effect of additional slip on four-wheel drive tractors operated without drawbar pull. Experiments were performed on asphalt surfaces and fields. A new measurement method was developed, and a device was constructed for the implementation of three tractor wheel drive operational modes (four-wheel drive, rear-wheel drive and front-wheel drive). As the result of the experiments, a relationship was found to describe the dynamic rolling radius for low-profile radial tires tested on rigid road surfaces. On this basis, the classical slip calculation method was modified. This phenomenon appears only on hard roads and soil surfaces with high adhesion coefficients and only within the low drawbar pull range.

scholarly journals Traction performance simulation for mechanical front wheel drive tractors: towards a practical computer tool

2013 ◽  
Vol 44 (2s) ◽  
Author(s):  
A. Battiato ◽  
E. Diserens ◽  
L. Sartori
Keyword(s):  
Field Tests ◽  
Front Wheel ◽  
Arable Soils ◽  
Wheel Load ◽  
Computer Tool ◽  
Performance Simulation ◽  
Wheel Drive ◽  
Silty Loam ◽  
Pulling Force ◽  
Drawbar Pull

An analytical model to simulate the traction performance of mechanical front wheel drive MFWD tractors was developed at the Agroscope Reckenholz-Tänikon ART. The model was validated via several field tests in which the relationship between drawbar pull and slip was measured for four MFWD tractors of power ranging between 40 and 123 kW on four arable soils of different texture (clay, clay loam, silty loam, and loamy sand). The pulling tests were carried out in steady-state controlling the pulling force along numerous corridors. Different configurations of tractors were considered by changing the wheel load and the tyre pressure. Simulations of traction performance matched experimental results with good agreement (mean error of 8% with maximum and minimum values of 17% and 1% respectively). The model was used as framework for developing a new module for the excel application TASCV3.0.xlsm, a practical computer tool which compares different tractor configurations, soil textures and conditions, in order to determine variants which make for better traction performance, this resulting in saving fuel and time, i.e. reducing the costs of tillage management.

Design and Performance Simulation of a Power-Integrated Transmission Mechanism

2013 ◽  
Vol 397-400 ◽  
pp. 388-392
Author(s):  
Chou Mo ◽  
Ji Qing Chen ◽  
Feng Chong Lan
Keyword(s):  
Hybrid Electric Vehicle ◽  
Rear Wheel ◽  
Front Wheel ◽  
Transmission Mechanism ◽  
System Structure ◽  
Performance Simulation ◽  
Operating Modes ◽  
Wheel Drive ◽  
And Performance ◽  
Four Wheel Drive

The power system structure of a hybrid electric vehicle (HEV) critically affects the performance of the vehicle. This study presents a power-integrated transmission mechanism that can provide six basic operating modes that can be further classified into 15 sub-modes. Switching clutch conditions helps transmission achieve speed and torque coupling. The proposed mechanism has CVT capability and an extended range capacity, and it is applicable to front-wheel-drive, rear-wheel-drive, or four-wheel-drive HEVs. A performance simulation on power and economy via Matlab and Cruise software demonstrates that the performance of the proposed transmission mechanism meets the target. Therefore, the mechanism is a feasible candidate for use in HEVs.

scholarly journals Mechanical Devices for Mass Distribution Adjustment: Are They Really Convenient?

Agronomy ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1820
Author(s):  
Massimiliano Varani ◽  
Michele Mattetti ◽  
Mirko Maraldi ◽  
Giovanni Molari
Keyword(s):  
Weight Distribution ◽  
Rear Wheel ◽  
Front Wheel ◽  
Original Position ◽  
Fuel Saving ◽  
Wheel Drive ◽  
Loam Soil ◽  
Mechanical Devices ◽  
Four Wheel Drive ◽  
Engine Power

Since the introduction of four-wheel drive (4WD) and especially front wheel assist (FWA), many studies have been conducted on the optimal weight distribution between tractor front and rear axles because this influences traction efficiency. The aim of this paper is to evaluate the traction and efficiency advantages in the adoption of mechanical ballast position adjustment devices. The tested device is an extendable ballast holder mounted on the front three-point hitch of the tractor, able to displace the ballast up to 1 m away from its original position. An estimation of the fuel consumption during ploughing with the extendable ballast holder in different configurations was performed. Tractive performance was evaluated through drawbar tests, performed on loam soil with a 4WD tractor having a maximum engine power of 191 kW and a ballasted mass of 9590 kg. Results show that changing the tractor weight distribution over the range allowed by the extendable ballast holder produces limited effects in terms of tractive performance and fuel saving. The adoption of such devices is thus ineffective if other fundamental factors such as tyre pressure, choice of the front-to-rear wheel combination and lead of the front wheels are not considered during tractor setup.

Analyses of the Relations Between Driving Types and Regenerative Braking in Electric Vehicles

2014 ◽  
Vol 926-930 ◽  
pp. 896-900
Author(s):  
Jin Long Liu ◽  
Zhi Wei Gao ◽  
Jing Ming Zhang
Keyword(s):  
Distribution Coefficient ◽  
Electric Vehicles ◽  
Theoretical Models ◽  
Rear Wheel ◽  
Front Wheel ◽  
Regenerative Braking ◽  
Force Distribution ◽  
Wheel Drive ◽  
Braking Force ◽  
Four Wheel Drive

The relations between Electric Vehicle (EV) drive arrangement and efficiency of regenerative braking were discussed. Firstly, conclusions were concluded according to the analyses of theoretical models. And then the validity of conclusions was proved by the simulations basing on the software of MATLAB/SIMULINK. The results indicate that the EV with four-wheel drive (4WD) pattern has the highest efficiency in regenerative braking mode. It also shows that whether the EV with front-wheel drive (FWD) pattern has higher efficiency than the EV with rear-wheel drive (RWD) pattern in regenerative braking mode depends on the braking force distribution coefficient.

Analytical Traction and Propulsion Analysis

2001 ◽  
Author(s):  
Junghsen Lieh
Keyword(s):  
Nonlinear Differential Equations ◽  
Rolling Resistance ◽  
Rear Wheel ◽  
Front Wheel ◽  
Inertia Force ◽  
Design Phase ◽  
Multiple Parameters ◽  
Electric Car ◽  
Wheel Drive ◽  
Four Wheel Drive

Abstract Conventional approach for vehicle traction and propulsion analysis used spreadsheets. This is inconvenient if one intends to vary a parameter, and it is even more difficult when multiple parameters are evaluated at the design phase. In this paper, it is intended to formulate two nonlinear differential equations representing road load and power consumption. By expanding inertia force, air drag, rolling resistance, gravitational force and tire tractive force, the equations can be simplified as the function of velocity v, i.e., s 1 v ˙ = s 2 - s 3 v 2 and m v ˙ = - r 1 v 3 - r 2 v + r 3 v , respectively. With these two equations, it allows engineers to use either numerical or analytical method to study key parameters at the design phase. To demonstrate the effectiveness of these equations, Wright State’s electric car model is used. The results for front-wheel drive (FWD), rear-wheel drive (RWD) and four-wheel drive (4WD) cases are presented.

Drive and Brake Joint Control of Acceleration Slip Regulation Road Test

2014 ◽  
Vol 971-973 ◽  
pp. 454-457
Author(s):  
Gang He ◽  
Li Qiang Jin
Keyword(s):  
Front Wheel ◽  
Driving Ability ◽  
Joint Control ◽  
Test Results ◽  
Road Test ◽  
Wheel Slip ◽  
Traction Control ◽  
Wheel Drive ◽  
Driving Wheel ◽  
Independent Design

Based on the independent design front wheel drive vehicle traction control system (TCS), we finished the two kinds of working condition winter low adhesion real vehicle road test, including homogenous pavement and separate pavement straight accelerate, respectively completed the contrastive experiment with TCS and without TCS. Test results show that based on driver (AMR) and brake (BMR) joint control ASR system worked reliably, controlled effectively, being able to control excessive driving wheel slip in time, effectively improved the driving ability and handling stability of vehicle.

Kinematic Displacement Analysis of a Double-Cardan-Joint Driveline

1987 ◽  
Author(s):  
I. S. Fischer ◽  
R. N. Paul
Keyword(s):  
Phase Angle ◽  
Relative Phase ◽  
Front Wheel ◽  
Constant Input ◽  
Computer Data ◽  
Output Displacement ◽  
Wheel Drive ◽  
In Series ◽  
The Difference ◽  
Cardan Joint

Abstract The input-output displacement relations of two Cardan joints arranged in series on a driveline has been investigated in detail, including the effects of unequal joints angles, the phase angle between the two Cardan joints and also such manufacturing tolerance errors as non-rigth angle link lengths and offset joint axes. A combined Newton-Raphson and Davidson-Fletcher-Powell optimization algorithm using dual-number coordinate-transformation matrices was employed to perform the analysis. An experiment was conducted to validate the results of the analysis. The apparatus consisted of a double-Cardan-joint driveline whose rotations were measured by optical shaft encoders that were sampled by a computer data-acquisition system. The equipment was arranged so that the phase angle between the joints and the offset angles between the shafts at each of the two joints could be readily varied. The “relative phase angle”, the difference between the phase angle of the two joints and the angle between the planes defined by the input and intermediate and the intermediate and output shafts, was found to be the significant factor. If the offset angles at both Cardan joints are equal, the double-Cardan-joint driveline function as a constant-velocity coupling when the magnitude of the relative phase angle is zero. If the offset angles at the two Cardan joints are unequal, a condition prevailing in the important front-wheel-drive automobile steering column, then fluctuation in output velocity for a constant input velocity is minimized although not eliminated for zero relative phase angle.

Test Results: Vehicle Responses to Simulated Drag Caused by Front Tire Tread Detachment — The Effect of Scrub Radius and Speed

2018 ◽  
Author(s):  
Mark W. Arndt ◽  
Stephen M. Arndt
Keyword(s):  
Lateral Displacement ◽  
Rear Wheel ◽  
Lateral Acceleration ◽  
Steering Wheel ◽  
Slip Angle ◽  
Yaw Rate ◽  
Wheel Drive ◽  
Steady State Responses ◽  
Four Wheel Drive ◽  
Left Front

The effects of reduced kingpin offset distance at the ground (scrub radius) and speed were evaluated under controlled test conditions simulating front tire tread detachment drag. While driving in a straight line at target speeds of 50, 60, or 70 mph with the steering wheel locked, the drag of a tire tread detachment was simulated by applying the left front brake with a pneumatic actuator. The test vehicle was a 2001 dual rear wheel four-wheel-drive Ford F350 pickup truck with an 11,500 lb. GVWR. The scrub radius was tested at the OEM distance of 125 mm (Δ = 0) and at reduced distances of 49 mm (Δ = −76) and 11 mm (Δ = −114). The average steady state responses at 70 mph with the OEM scrub radius were: steering torque = −24.5 in-lb; slip angle = −3.8 deg; lateral acceleration = −0.47 g; yaw rate = −8.9 deg/sec; lateral displacement after 0.75 seconds = 3.1 ft and lateral displacement after 1.5 seconds = 13.1 ft. At the OEM scrub radius, responses that increased linearly with speed included: slip angle (R2 = 0.84); lateral acceleration (R2 = 0.93); yaw rate (R2 = 0.73) and lateral displacement (R2 = 0.59 and R2 = 0.87, respectively). At the OEM scrub radius, steer torque decreased linearly with speed (R2 = 0.76) and longitudinal acceleration had no linear relationship with speed (R2 = 0.09). At 60 mph and 70 mph for both scrub radius reductions, statistically significant decreases (CI ≥ 95%) occurred in average responses of steer torque, slip angle, lateral acceleration, yaw rate, and lateral displacement. At 50 mph, reducing the OEM scrub radius to 11 mm resulted in statistically significant decreases (CI ≥ 95%) in average responses of steer torque, lateral acceleration, yaw rate and lateral displacement. At 50 mph the average slip angle response decreased (CI = 87%) when the OEM scrub radius was reduced to 11 mm.

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