Bela Lantos

6701694668

Publications - 6

Time optimal control of ground vehicles

Gyorgy Max Bela Lantos

Publication Name: Sisy 2014 IEEE 12th International Symposium on Intelligent Systems and Informatics Proceedings

Publication Date: 2014-10-14

Volume: Unknown

Issue: Unknown

Page Range: 245-250

Description:

The paper deals with the time optimal control of automatically driven cars modeled with gear shift as discrete control input beside the continuous ones in a test path between corridors. The car is required to avoid a static obstacle or performing double lane change. The problem can be formulated as a mixed-integer optimal control problem (MIOCP). The resulting MIOCP is solved by reformulating it to static mixed-integer nonlinear program (MINLP) using time discretization and direct multiple shooting method. Non-commercial open software packages are applied that substantially use the gradients of the objective function and the Jacobians of the constraints exploiting sparsity. A novel algorithm and implementation is presented for computing the derivatives of the complex state trajectory joining equations. This algorithm was given in the form of matrix differential equations whose structure allowed to compute their solution using RK4 in matrix form. The elaborated method can be applied both for combustion engine and electric driven cars. It can form the basis to generate an offline database of a central general collision avoidance system (CAS) for varying path parameters on a grid which can support real time applications.

Open Access: Yes

DOI: 10.1109/SISY.2014.6923594

Formation control of a large group of UAVs with safe path planning and obstacle avoidance

Gergely Regula Bela Lantos

Publication Name: 2014 European Control Conference Ecc 2014

Publication Date: 2014-07-22

Volume: Unknown

Issue: Unknown

Page Range: 1522-1529

Description:

In this article we propose a hierarchical control structure for multi-agent systems. The main objective is to perform formation change manoeuvres, with guaranteed safe distance between each two vehicles throughout the whole mission, even if motion is restricted to a limited space and static obstacles are present. The key components that ensure safety are a robust control algorithm that is capable of stabilising the group of vehicles in a desired formation and a higher level path generation method that provides all the vehicles with safe paths, based on graph theoretic considerations. The method can efficiently handle a large group of any type of vehicles. As an illustration, the results are applied to a group of 18 quadrotor UAVs, where 2 of the UAVs cannot receive information from the others.

Open Access: Yes

DOI: 10.1109/ECC.2014.6862411

Nonlinear moving horizon predictive control of ground vehicles

Gyorgy Max Bela Lantos

Publication Name: Cinti 2014 15th IEEE International Symposium on Computational Intelligence and Informatics Proceedings

Publication Date: 2014-01-30

Volume: Unknown

Issue: Unknown

Page Range: 421-426

Description:

The paper deals with the approximately time-optimal control of automatically driven cars modeled with gear shift as discrete control input beside the continuous ones in a path between two path boundaries. The path boundaries are defined by their corner points that may be the result of image processing in real time or prescribed in advance. The path is divided into sections for which separate optimum control problems are solved in a nonlinear moving horizon predictive control (NMHPC) fashion increasing the semi-online character of the approach. In each section the problem can be formulated as a mixed-integer optimal control problem (MIOCP). The resulting MIOCP is solved by reformulating it to static mixed-integer nonlinear program (MINLP) using time discretization and direct multiple shooting method. Non-commercial open software packages are applied that substantially use the gradients of the objective function and the Jacobians of the constraints exploiting sparsity. The elaborated method can be applied both for combustion engine and electric driven cars. It can also form the basis to generate an offline database of a central general collision avoidance system (CAS) for varying path parameters on a grid which can further support real time applications.

Open Access: Yes

DOI: 10.1109/CINTI.2014.7028712

Time optimal control of four-in-wheel-motors driven electric cars

Gyorgy Max Bela Lantos

Publication Name: Periodica Polytechnica Electrical Engineering and Computer Science

Publication Date: 2014-01-01

Volume: 58

Issue: 4

Page Range: 149-159

Description:

The paper deals with the time optimal control of automatically driven electric cars in a test path under state and input constraints. The problem can be formulated as a dynamic nonlinear optimal control problem (DNOCP). The resulting DNOCP is solved by reformulating it to a static nonlinear program (NLP) using time discretization and direct multiple shooting methods. A novel method is presented to convert the optimal solution obtained using the single-track model to the optimal control of four-in-wheels-motors driven (4WD) cars. The conversion assures similar motion of the COG of both models and optimal distribution of the longitudinal wheel forces. A discrete model predictive control (MPC) is proposed for the linearized 4WD vehicle model under perturbations which uses the distributed wheel forces and optimizes the perturbations with analytically solvable end constraints. The elaborated method can form the basis to generate an offline database of a general collision avoidance system (CAS).

Open Access: Yes

DOI: 10.3311/PPee.7806

High precision GPS positioning with multiple receivers using carrier phase technique and sensor fusion

László Kis Bela Lantos

Publication Name: Periodica Polytechnica Electrical Engineering and Computer Science

Publication Date: 2013-01-01

Volume: 57

Issue: 3

Page Range: 83-97

Description:

This paper presents a carrier phase differential GPS technique for vehicle navigation. The orientation and position of the vehicle can reliably be calculated by the proposed solutions. The developed methods are aided by inertial and magnetic sensors. They are designed for dead reckoning and to handle phase slip. Therefore these solutions can be applied when the set of the available satellites changes frequently. Extended Kalman filters perform state estimation. The paper also presents the low-cost hardware/software architecture of the navigation system. The effectiveness of the methods have been proven in real car and flight tests.

Open Access: Yes

DOI: 10.3311/PPee.2102

Formation control of quadrotor helicopters with guaranteed collision avoidance via safe path

Gergely Regula Bela Lantos

Publication Name: Periodica Polytechnica Electrical Engineering and Computer Science

Publication Date: 2012-01-01

Volume: 56

Issue: 4

Page Range: 113-124

Description:

In this article we propose a hierarchical control structure for multi-agent systems. The main objective is to perform formation change manoeuvres, with guaranteed safe distance between each two vehicles throughout the whole mission. The key components that ensure safety are a robust control algorithm that is capable of stabilising the group of vehicles in a desired formation and a higher level path generation method that provides safe paths for all the vehicles, based on graph theoretic considerations. The method can effciently handle a large group of any type of vehicles. In the article we focus on the control of quadrotor UAVs, thus the results are illustrated in 4D on a group of such vehicles.

Open Access: Yes

DOI: 10.3311/PPee.7080