Renewable energy sources are a growing branch of industry. One such source is wind farms, which have significantly increased their number over recent years. Alongside the increased number of turbines, maintenance problems are growing. There is a need for newer and less intrusive predictive maintenance methods. About 40% of all turbine failures are due to bearing failure. This paper presents a modified neural direct classifier method using raw accelerometer measurements as input. This proprietary platform allows for better damage prediction results than convolutional networks in vibration spectrum image analysis. It operates in real time and without signal processing methods converting the signal to a time–frequency spectrogram. Image processing methods can extract features from a set of preset features and based on their importance. The proposed method is not based on feature extraction from image data but on automatically finding a set of features from raw tabular data. This fact significantly reduces the computational cost of detection and improves the failure detection accuracy compared to the classical methods. The model achieved a precision of 99.32% on the validation set, and 96.3% during bench testing. These results were an improvement over the method that classifies time–frequency spectrograms of 97.76% for the validation set and 90.8% for the real-world tests, respectively.
Optimal control of multivariable systems is a complex dynamic process that minimizes the cost function to obtain the optimal control strategy. Unfortunately, for nonlinear systems, it is not possible to use the traditional linear quadratic regulator (LQR), which would be optimal over the entire range of parameter variation. The problem of nonlinear multivariable systems and their optimal control is very momentous. The solution presented in this paper is based on the application of Reinforcement Learning (RL) networks in controlling a five-degree-of-freedom overhead crane system. Additionally, unlike the classical approach, the algorithm is adapted to directly analyze tabular data of inputs and outputs of the controlled model instead of analyzing its state as feedback (model-free). Implementing the new control structure for the multivariable system improved control quality compared to the classical LQR controller with linearization at the operating point. In addition to quality, the resource indicators, which in the LQR controller are represented by the matrix R, have been significantly improved. The architecture of the neural control system is presented, ensuring that over the entire range of nonlinearity, the quality of control is preserved while reducing the cost of its resource intensity. Obtaining optimal control with reduced resources for its implementation induces a wide range of applications of such neural control in engineering systems. The effectiveness of the proposed control system has been demonstrated in simulation studies. The simulation results present the system’s excellent control performance and adaptability over the entire range of object nonlinearity. The neural algorithm resulted in significantly shorter adjustment time and better control quality with significantly less system resource consumption and increased system dynamics.
This paper presents methods for modelling and optimising the industrial limestone grinding process carried out using a real limestone plant. Two key process evaluation indicators were developed: specific electric energy consumption and an extended indicator that also includes gas usage. Using process data collected from the SCADA system and results from industrial factorial experiments, regression artificial neural network models were developed, with controllable process parameters used as inputs. In the next phase, black-box optimisation was performed using Bayesian and genetic algorithms to identify optimal mill operating settings. The results demonstrate significant improvements in energy efficiency, with energy savings reaching up to 48% in selected cases. The proposed methodology can be effectively applied to enhance energy performance in similar industrial grinding processes.
Overhead cranes are a key component of many industrial processes, enabling the rapid and safe transportation of loads. An important aspect of their operation is reliability, including fault tolerance of components such as sensors. In the event of a sensor failure, the control system must be able to continue operation, using only the available information about the object's condition. This paper presents a control system for a bridge crane based on reinforcement learning, taking into account the object's state estimates. The system was designed to be robust to sensor failures while maintaining high control quality. In simulation studies, the effectiveness of control with different state estimation accuracy was investigated. The results showed that the system is able to ensure stable and safe operation of the crane, even in the case of errors in state estimation.
The growing number of wind farms is creating an increased demand for their trouble-free operation. Damage to their components can be catastrophic. A particular component that can be subject to damage during long-term operation and is difficult to diagnose is the mechanical gearbox located in the turbine. Traditional approaches to the subject of damage detection require, in the final stage, the involvement of an expert. Therefore, the article proposes a method based on the Deep Learning solution. A transfer learning method and a pre-trained Inception V3 network were used. A gearbox with in three states of healthy, worn out but still working and damaged was analyzed. Signal spectrograms were created from accelerometric measurements and then used as input for the neural network. Various approaches to creating spectrogram images were tested. The InceptionV3 network was taught on images generated in grayscale, and RGB and HSV. Channel reduction in the form of using grayscale improved the speed of the algorithm at the expense of precision. The use of HSV scale, on the other hand, made it more precise in detecting a worn out state.