Agricultural Electric Vehicles Research Articles

Evaluation of gear reduction ratio for a 1.6 kW multi-purpose agricultural electric vehicle platform based on the workload data

Evaluation of gear reduction ratio for a 1.6 kW multi-purpose agricultural electric vehicle platform based on the workload data

Study on the Change of Power Consumption Structure in Xumai Township, Nimu County, Lhasa, Xizang

The research on the evolution of rural power consumption structure in Xizang reflects the information on rural power development in Xizang, and the information on rural power development shows the people's living standards and demand trends. In order to understand the depth of changes in the power consumption structure of farmers and herdsmen households, the project team conducted a field survey of the changes in power supply sources, power consumption structure, power consumption equipment, and operation and management status of Sumai Township, a typical village in Nimu County, Lhasa City, Xizang over the years, and explored the history and trend of power development in remote villages in Xizang. Field research has found that before 2014, the township mainly relied on small-scale independent solar photovoltaic power supply, which was almost used for lighting; Since the implementation of the State Grid in 2014, electricity consumption has shifted from low voltage to wide voltage. In the past three years, the annual electricity consumption growth rate in Xumai Township has exceeded 6%, and the power supply stability has reached 90%. At the same time, the township utilizes solar photovoltaic street lights. The electrical appliances used have developed from a single lamp to power appliances such as household appliances, agricultural electric vehicles, tsamba machines and oil presses. The distribution line of the township is gradually being replaced with medium and low voltage, and is equipped with a 35kV Xumai substation. The 10kV medium and low voltage distribution network project of the rural power grid is gradually being put into operation and put into practice. However, research has found that villagers hope to use more clean energy such as solar energy for power supply and heating, in order to reduce the cost of electricity and gas bills.

Zigbee Enabled Iot Based Intelligent Lane Control System for Autonomous Agricultural Electric Vehicle Application

Zigbee Enabled Iot Based Intelligent Lane Control System for Autonomous Agricultural Electric Vehicle Application

Model predictive control system based on direct yaw moment control for 4WID self-steering agriculture vehicle

A model predictive control (MPC) approach based on direct yaw moment control (DYC) was proposed to realize the self-steering drive for a newly autonomous four-wheel independent-drive (4WID) agricultural electric vehicle. The front axle and rear axle of the vehicle chassis could rotate simultaneously around their respective center points and cut the turning radius in half at most through specific mechanical chassis structure design and four-wheel electrical drive. It had great potential to reduce wheel traffic damage to field crops if two rear electrical drive wheels can be controlled to follow wheel tracks of two front wheels during self-steering operation. Therefore, firstly, a two-degree-freedom dynamics model presenting this agricultural electric vehicle was constructed. Then, an MPC controller combined with DYC was applied to arrange torques from four wheels to match desired turning angles, direct yaw moments and travel speeds. The simulation results existed small steady error of steering angles below 0.22% as they were set at 5°, followed with yaw moment under 0.17% and velocity less than 1%. Finally, according to experiment results, the vehicle successfully made a working turning radius of 9.1 m with maximum error of 0.55% when desired steering angles were 5° at the speed of 1 m/s and a minimum turning radius of 1.51 m with maximum error of 6.6% when steering angles were 30° at the speed of 0.5 m/s. It verified that the 4WID agricultural electric vehicle could drive autonomously and steady with small self-steering angle error under the proposed control system and has a feasibility to reduce wheel traffic damage during driving and operation. Keywords: agriculture mechanization, 4WID electric vehicle, self-steering, model predictive control DOI: 10.25165/j.ijabe.20211402.5283 Citation: Liu H, Yan S C, Shen Y, Li C H, Zhang Y F, Hussain F. Model predictive control system based on direct yaw moment control for 4WID self-steering agriculture vehicle. Int J Agric & Biol Eng, 2021; 14(2): 175–181.

Model predictive control system based on direct yaw moment control for 4WID self-steering agriculture vehicle

A model predictive control (MPC) approach based on direct yaw moment control (DYC) was proposed to realize the self-steering drive for a newly autonomous four-wheel independent-drive (4WID) agricultural electric vehicle. The front axle and rear axle of the vehicle chassis could rotate simultaneously around their respective center points and cut the turning radius in half at most through specific mechanical chassis structure design and four-wheel electrical drive. It had great potential to reduce wheel traffic damage to field crops if two rear electrical drive wheels can be controlled to follow wheel tracks of two front wheels during self-steering operation. Therefore, firstly, a two-degree-freedom dynamics model presenting this agricultural electric vehicle was constructed. Then, an MPC controller combined with DYC was applied to arrange torques from four wheels to match desired turning angles, direct yaw moments and travel speeds. The simulation results existed small steady error of steering angles below 0.22% as they were set at 5°, followed with yaw moment under 0.17% and velocity less than 1%. Finally, according to experiment results, the vehicle successfully made a working turning radius of 9.1 m with maximum error of 0.55% when desired steering angles were 5° at the speed of 1 m/s and a minimum turning radius of 1.51 m with maximum error of 6.6% when steering angles were 30° at the speed of 0.5 m/s. It verified that the 4WID agricultural electric vehicle could drive autonomously and steady with small self-steering angle error under the proposed control system and has a feasibility to reduce wheel traffic damage during driving and operation. Keywords: agriculture mechanization, 4WID electric vehicle, self-steering, model predictive control DOI: 10.25165/j.ijabe.20211402.5283 Citation: Liu H, Yan S C, Shen Y, Li C H, Zhang Y F, Hussain F. Model predictive control system based on direct yaw moment control for 4WID self-steering agriculture vehicle. Int J Agric & Biol Eng, 2021; 14(2): 175–181.

Optimization of the Housing Shape Design for Radiated Noise Reduction of an Agricultural Electric Vehicle Gearbox

As the demand for agricultural electric vehicles increases, it is becoming important to conduct noise reduction in consideration of the characteristics of an electric powertrain. This study was conducted to optimize the shape design of gearbox housing for radiated noise reduction of an agricultural electric vehicle gearbox. The noise and vibration of the gearbox were measured considering the noise characteristics of the electric vehicle gearbox, which radiates high-frequency pure tone noise. The main noise source radiated by the structural vibration of the gearbox housing was identified and considered when modeling the loading conditions in the numerical analysis. To improve the reliability, the finite element (FE) model was updated and validated. Internal machine elements were modeled as a substructure through a reduced-order modeling method to reduce the computing time and apply a constant gear excitation force. The weak areas of structure were determined and it was used as the design area for optimization. The topology optimization technique was used to reduce the equivalent radiated power (ERP) which was used as an indicator of radiated noise level. The maximum value of the ERP decreased under all operating conditions at the rated speed.

Rib Design for Improving the Local Stiffness of Gearbox Housing for Agricultural Electric Vehicles

In this work, a rib design process is proposed to improve the local stiffness of gearbox housing for agricultural electric vehicles. Unlike conventional engines, electric powertrain noise includes high frequency factors and pure tones. Considering these characteristics, local stiffness was evaluated in the frequency range of interest for the prediction of dynamic behavior. The local stiffness of the gearbox housing was evaluated using the finite element (FE) model. Experimental modal analysis and FE model update were conducted to ensure the reliability of the results. Using the results of local stiffness evaluations, the stiffness weak point was identified, and the rib design location was selected through a strain analysis. The shape of the ribs was parameterized by width, length, and height, and parameter studies were used to compare the local stiffness increase rate according to the rib design pattern. According to the results, the stiffness increase rate against the same mass was distributed differently according to the rib shape, and the most efficient rib shape was selected from a manufacturing perspective.

State of the art of autonomous agricultural off-road vehicles driven by renewable energy systems

Achieving independence from fossil fuels and reducing emissions by increasing energy efficiency and utilizing green vehicles, such as hybrid electric vehicles and alternative green fuels, are among the main goals of energy policies globally. Although electric cars were introduced many years ago, agricultural electric vehicles have recently gained attention. Beyond emissions reductions, the benefits of agricultural electric vehicles include precise control, continuous variable speeds, and overload capability functionality. Moreover, such technology paves the way for the emergence of autonomous connected vehicles, which enhance work quality and increase operator comfort. Along with the electrification of agricultural vehicles, on-site production of renewable energy to supply their required power enhances the benefits in terms of increased efficiency and energy independence as a future-oriented approach. This paper outlines the trends in development and future perspectives of autonomous farm vehicles premised on green energies, with on-site energy production as a byproduct.

Power Conversion System for Electric Power Take-off of Agricultural Electric Vehicle

Power Conversion System for Electric Power Take-off of Agricultural Electric Vehicle

Assessment of agricultural electric vehicles based on photovoltaics in China

Solar-powered agricultural vehicles facilitate the reduction in the use of fossil fuel, decreasing the emissions of air pollutants and greenhouse gases. This paper assessed the agricultural electric vehicle (AEV) based on photovoltaics in China, taking into consideration three aspects, i.e., power supply mode for AEV, power of AEV, and economy analysis. The power supply mode, whether on-board photovoltaic (PV) system or off-board PV system, is subjected to the size and the power of the designed AEV, but the AEV's power depends on the area of PV panels which affects the initial investment cost of the PV system and the AEV. Three analysis indicators including payback period, net present value, and benefit-cost ratio were taken into consideration when comparing the projects of 10 kW and 30 kW AEVs based on PV system and the respective conventional tractors. Results show that the off-board PV system is more applicable to the AEV, the PV-based AEV with low power is a wise, economical investment, and this type of system is particularly appropriate for rural and remote areas in China, although the initial investment cost is huge for the most of the Chinese farmers.

Study on Reducing Cogging Torque of Interior PM Motor for Agricultural Electric Vehicle

This paper proposes a new design of rotor shape of Interior Permanent Magnet Synchronous Motor (IPMSM) used for agricultural electric vehicle (AEV). The distribution of the residual magnetic flux density at the air gap is modified by rotor surface shape and V-type magnet angle. As a result, cogging torque and physical characteristic have been improved, and back electromotive force (back-EMF) of the suggested model has been improved to be closest to sine wave form compared to initial model. The validity of the proposed rotor shape optimization is confirmed by the manufactured IPM rotor core and measured the performance of the cogging torque.

Fundamental Study on the Improvement of Efficiency of a Fuel Cell Hybrid Power System for Agricultural Electric Vehicles

Fundamental Study on the Improvement of Efficiency of a Fuel Cell Hybrid Power System for Agricultural Electric Vehicles

Electromagnetic Field and Thermal Linked Analysis of Interior Permanent-Magnet Synchronous Motor for Agricultural Electric Vehicle

This paper presents a 3D numerical analysis of the thermal transient behavior of the air-cooled interior permanent-magnet synchronous motor (IPMSM) for agricultural electric vehicle (AEV) using finite-element method (FEM). The air-cooled IPMSM is investigated the temperature variation for the insulation of winding coil and demagnetization of permanent-magnet during the rated operation. Therefore, the prediction of a motor temperature is necessary at the motor design stage. This paper shows a good agreement both the numerical calculation and experimental results. The proposed method, electromagnetic field and thermal linked analysis, is able to predict the temperature distribution of IPMSM with the rated 7.5 kW continuous power.

Traction Control for an Agricultural Electric Vehicle

Traction Control for an Agricultural Electric Vehicle