Operational Feasibility Assessment of Battery Electric Construction Equipment Based on In-Use Activity Data

Despite the significant progress in on-road vehicle electrification, the majority of construction equipment types are still using conventional diesel engines. Though there has been a steady flow of studies in this field, not all equipment types have yet been evaluated. This paper contributes to filling that data gap by analyzing real-world second-by-second activity data from 17 off-road vehicles across six equipment types to investigate their electrification potential. The collected data are used to determine real-world power and torque demands—which are then used to select currently available electric motors suited for electrification of these types of equipment. Required battery sizes for battery electric operation are also calculated considering recorded energy demands, and battery sizes are standardized across equipment types for realistic implementation. The resulting battery electric systems are simulated to determine their effectiveness in fulfilling real-world activity demands. The results show that four of the six types can be electrified to a significant extent using battery electric powertrains with a single-motor set-up, while the remaining two types are more suitable for hybridization because of their high energy needs.

Digital twin of the rotor-shaft of a lightweight electric motor during aerobatics loads

Purpose This paper aims to present airworthiness considerations regarding a shaft of an electric motor. A fatigue lifetime prediction analysis based on one-step load spectrum is performed during high-cycle fatigue. Time-dependent normal and shear stress components are estimated using a high-fidelity digital twin built in Siemens PLM Nx Nastran as a finite element model (FEM). Linear and centrifugal acceleration as well as gyroscopic moment, motor torque, propeller thrust and thermal loads are considered. The equivalent cyclic degree of utilisation and a safety margin against the slip of a press-fitted shaft to rotor hub connection is estimated. Design/methodology/approach A load analysis using FEM is presented. The numerically obtained results are verified on an analytical and a semi-empirical basis. Findings The shaft of the electric motor can sustain 74 h of operation if burdened with aerobatic loads. Its load capacity equals 48% for the overall safety factor of 2.25. Practical implications The paper presents a specific, easily identifiable advance in knowledge that can be applicable in safety flight analysis issues. Originality/value The work presents a rotor of a novel lightweight electric motor for aircraft applications, which is a successor of the electric motor set recently in Extra 330E. The work delivers a computational estimation of the shaft life.

Cost Analysis Based Algorithm for Load Shared Multiple Induction Motor Set-up

Majority of the industrial processes are generally carried out using a motor-drive arrangement. The quality of the final output of a process largely depends on the performance and reliability of the motor drive sets. Failure of motor running the process can result in a complete shutdown of the process. Certain processes may not even afford to offer downtime for maintenance. Downtime of motors can severely affect the quality of the endproduct of a process. Although there are many tools and algorithms to predict the failure and maintenance patterns for motor, this paper presents a novel means to increase the reliability of motor-drive arrangements. It also presents a cost analysis framework in choosing a motor-drive arrangement for a particular load.

Context-dependent tactile texture-sensitivity in monkey M1 and S1 cortex

Caudal primary motor cortex (M1, area 4) is sensitive to cutaneous inputs, but the extent to which the physical details of complex stimuli are encoded is not known. We investigated the sensitivity of M1 neurons (4 Macaca mulatta monkeys) to textured stimuli (smooth/rough or rough/rougher) during the performance of a texture discrimination task and, for some cells, during a no-task condition (same surfaces; no response). The recordings were made from the hemisphere contralateral to the stimulated digits; the motor response (sensory decision) was made with the nonstimulated arm. Most M1 cells were modulated during surface scanning in the task (88%), but few of these were texture-related (24%). In contrast, 44% of M1 neurons were texture related in the no-task condition. Recordings from the neighboring primary somatosensory cortex (S1), the potential source of texture-related signals to M1, showed that S1 neurons were significantly more likely to be texture related during the task (57 vs 24%) than M1. No difference was observed in the no-task condition (52 vs. 44%). In these recordings, the details about surface texture were relevant for S1 but not for M1. We suggest that tactile inputs to M1 were selectively suppressed when the animals were engaged in the task. S1 was spared these controls, as the same inputs were task-relevant. Taken together, we suggest that the suppressive effects are most likely exerted directly at the level of M1, possibly through the activation of a top-down gating mechanism specific to motor set/intention. NEW & NOTEWORTHY Sensory feedback is important for motor control, but we have little knowledge of the contribution of sensory inputs to M1 discharge during behavior. We showed that M1 neurons signal changes in tactile texture, but mainly outside the context of a texture discrimination task. Tactile inputs to M1 were selectively suppressed during the task because this input was not relevant for the recorded hemisphere, which played no role in generating the discrimination response.

Flywheel Energy Storage for Wind Energy System with SEIG-Motor Set

Intermittent wind energy in producing optimal power flow could lead to unstable generated power. Due to this, an energy storage that can release and absorb energy need to be used in order maintains the generated voltage at the permitted quality for the load. Nowadays, tons of energy storage systems are used in storing the energy. Flywheel energy storage system (FESS) becomes one of potential mechanism that can be used to smooth the voltage output of wind turbine due to its advantages. The aim of this study is to design and implement a FESS for critical load in a wind energy system that can store energy for a short time period. Then, period of the voltage generated by FESS using different capacitance is analyzed. FESS consists of a self-excited capacitance induction motor-generator set (SEIG), controller circuit and flywheel rotor. In this study, a three phase asynchronous induction machine is used as a motor-generator due to its simplicity, cheap, robust and less maintenance. The flywheel and SEIG-motor set could store the energy for a short period of time, which can be used to compensate for wind instability. Results show that FESS generates variable powers that compensate short time power to the wind system.

Test System of the Static and Dynamic Performance of the Proportional Solenoid

Proportional solenoid is the key component in electro-hydraulic proportional control systems. The static and dynamic performance of the proportional solenoid directly affects the control accuracy, response speed and reliability of the whole system. To test the static and dynamic performance of the proportional solenoid accurately, reliably as well as conveniently, an automatic test system with the combination of the sensor and control technology is developed in this paper. The entire system consists of mechanical structure which could position the proportional solenoid and adjust the displacement, the control and measurement part whose main function is to control the motion of the stepper motor ,set the drive current of the solenoid through the proportional amplifier and collect data. The experimental apparatus allows rapid switch between static test and dynamic test through two vertically-positioned pins and other accessories, which makes this test system different from the others. The experimental results demonstrate the feasibility and the rationality of the design.