TY - JOUR A1 - Sauer, Timm A1 - Gorks, Manuel A1 - Spielmann, Luca A1 - Zindler, Klaus A1 - Jumar, Ulrich T1 - Adaptive self-learning controllers with disturbance compensation for automatic track guidance of industrial trucks JF - SICE Journal of Control, Measurement and System Integration N2 - This paper presents an extended control concept for automatic track guidance of industrial trucks in intralogistic systems. It is based on Reinforcement Learning (RL), a method of Artificial Intelligence (AI). The presented approach is able to adapt itself to different industrial truck variants and to the associated specific vehicle parameters. In order to avoid starting the whole training of the controller for each truck variant from scratch, the training process is divided into two steps. In the first step, the controller is trained on a simplified linear model using parameters of a nominal vehicle variant. Based on this, the control parameters are only fine-tuned in the second step using a more complex nonlinear model, representing the real industrial truck. In this way, the controller is adapted to the actual truck variant and the corresponding parameter values. By using the nonlinear model, it can be ensured that the forklift’s dynamic is approximated within the entire operating range, even at high steering angles. Moreover, the influence of the disturbance variable of the system (path curvature) is compensated by considering this a priori knowledge within the control design. Therefore, the Artificial Neural Networks (ANN) of the RL controller and the observation vector are suitably adjusted. In this way, the occurring path curvatures can be considered in both training steps and the control parameters can be optimized accordingly. Thus, the influence of the disturbance variable can be compensated, which significantly improves the control quality. In order to demonstrate this, the new approach is compared to an RL control concept, which is not considering the disturbance variable and to a classical two-degrees-of-freedom (2DoF) control approach. KW - Flurförderer KW - Spurführung KW - Künstliche Intelligenz Y1 - 2023 U6 - https://doi.org/10.1080/18824889.2023.2183009 VL - 2023 IS - Vol. 16, No. 1 SP - 84 EP - 97 ER - TY - CHAP A1 - Sauer, Timm A1 - Spielmann, Luca A1 - Gorks, Manuel A1 - Zindler, Klaus A1 - Jumar, Ulrich T1 - Model Predictive Control of Industrial Trucks with AI-based Plant Model Selection T2 - 9th International Conference on Control, Decision and Information Technologies (CoDIT) N2 - In this paper, a new control concept for automatic track guidance of forklifts within a heterogeneous logistics fleet is presented. The proposed control scheme is universally applicable and based on Artificial Intelligence (AI). The lateral control is realized using a Model Predictive Controller (MPC). In order to take into account the diversity of the industrial truck variants, a multi-model approach is used. Therefore, a plant model for each truck variant is integrated into the MPC. In a practical application, the most suitable model has to be selected. This decision is based on AI in the form of an Artificial Neural Network (ANN). It is able to distinguish the different truck variants based on that part of the plant's state vector, which represents the vehicle dynamic characteristics. Thus, the appropriate model can be used, which significantly improves the control quality and guarantees an accurate track guidance of different forklifts. Due to the AI-based selection of the model, the computational effort can be kept low and real-time capability can be ensured. In order to classify the performance of the proposed control concept, its simulation results are compared to the closed-loop behavior, using a classical MPC. KW - automatic control KW - robust control KW - AI KW - ANN KW - Flurförderer KW - Künstliche Intelligenz Y1 - 2023 UR - https://ieeexplore.ieee.org/abstract/document/10284427 U6 - https://doi.org/10.1109/CoDIT58514.2023.10284427 VL - 2023 IS - Conference Proceedings SP - 263 EP - 268 ER - TY - CHAP A1 - Sauer, Timm A1 - Gorks, Manuel A1 - Spielmann, Luca A1 - Hepp, Nils A1 - Zindler, Klaus A1 - Jumar, Ulrich T1 - AI-based control approaches for lateral vehicle guidance of industrial trucks T2 - IFAC WC 2023 – The 22nd World Congress of the International Federation of Automatic Control 2023, Yokohama, Japan, 09.07.2023 - 14.07.2023 N2 - Two different control concepts for the automatic track guidance of forklifts are proposed. Both approaches are based on Reinforcement Learning (RL), a method of Artificial Intelligence (AI), and are able to take into account time-variant parameters, such as the vehicle velocity, and to reduce the influence of the path curvature, the most important disturbance variable of lateral vehicle control. In the first approach, both, the path curvature and the vehicle velocity signal, are provided to the controller in addition to the state variables of the controlled system. By varying the corresponding parameters in the training process, both signals can be considered and the control parameters can be optimized accordingly. In the second approach, several controllers (multi-model concept) considering the path curvature are used and the varying vehicle velocity is taken into account using a gain-scheduling concept. Considering time-variant vehicle parameters and the influence of the disturbance variable during operation, a stable track guidance is guaranteed within the whole speed range of the industrial trucks. KW - Artificial intelligence, Lateral vehicle control, Intelligent transportation systems KW - Flurförderer KW - Künstliche Intelligenz Y1 - 2023 UR - https://www.sciencedirect.com/science/article/pii/S2405896323019092 U6 - https://doi.org/https://doi.org/10.1016/j.ifacol.2023.10.1501. ER -