Application of Cubature Information Filter for Underwater Target Path Estimation

Bearings-only tracking plays a pivotal role in passive underwater surveillance. Using noisy sonar bearing measurements, the target motion parameters (TMP) are extensively estimated using the extended Kalman filter (EKF) because of its simplicity and low computational load. The EKF utilizes the first order approximation of the nonlinear system in estimation of the TMP that degrades the accuracy of estimation due to the elimination of the higher order terms. In this paper, the cubature Kalman filter (CKF) that captures the system nonlinearity upto third order is proposed to estimate the TMP. The CKF is further extended using the information filter (IF) to provide decentralized data fusion, hence the filter is termed as cubature information filter (CIF). The results are generated using Matlab with Gaussian assumption of noise in measurements. Monte-Carlo simulation is done and the results demonstrate that the CIF accuracy is same as that of UKF and this indicates the usefulness of the algorithm for state estimation in underwater with the required accuracy.

Stage performance layout design based on artificial intelligence technology

The main purpose of stage performance arrangement is to improve the audience’s satisfaction with the stage performance. For this purpose, the stage performance arrangement design method based on artificial intelligence technology was explored. In the process of stage performance action retrieval, the offline link uses the method of frame distance definition based on quaternion in artificial intelligence technology to construct the structure of motion database digraph; the real-time link determines the corresponding vertex and edge in the digraph. According to the vertices and edges in the directed graph, the performer’s trajectory was determined, and the multi-resolution filtering algorithm in artificial intelligence technology was used to extract the motion path in the performer’s trajectory. The target path of stage performance arrangement was obtained by mapping the performer’s motion path through zoom processing. Based on the goal path, by arranging the control position of the performer’s root joint and correcting the direction of the performer, the movement track of the performer in the stage performance process was reconstructed, and the stage performance layout design was realized by combining with the position arrangement of the stage performance motion segment. The experimental results show that the method can accurately plan the performers’ path and improve the user’s satisfaction with the stage performance.

A Novel Path Planning Algorithm for Truck Platooning Using V2V Communication

In truck platooning, the leading vehicle is driven manually, and the following vehicles run by autonomous driving, with the short inter-vehicle distance between trucks. To successfully perform platooning in various situations, each truck must maintain dynamic stability, and furthermore, the whole system must maintain string stability. Due to the short front-view range, however, the following vehicles’ path planning capabilities become significantly impaired. In addition, in platooning with articulated cargo trucks, the off-tracking phenomenon occurring on a curved road makes it hard for the following vehicle to track the trajectory of the preceding truck. In addition, without knowledge of the global coordinate system, it is difficult to correlate the local coordinate systems that each truck relies on for sensing environment and dynamic signals. In this paper, in order to solve these problems, a path planning algorithm for platooning of articulated cargo trucks has been developed. Using the Kalman filter, V2V (Vehicle-to-Vehicle) communication, and a novel update-and-conversion method, each following vehicle can accurately compute the trajectory of the leading vehicle’s front part for using it as a target path. The path planning algorithm of this paper was validated by simulations on severe driving scenarios and by tests on an actual road. The results demonstrated that the algorithm could provide lateral string stability and robustness for truck platooning.

A Dual Quaternion Based Method for Estimating Margins for Planning Target Volumes in Radiotherapy

This objective of this paper is to develop a dual quaternion based method for estimating target volumes in radiation therapy for head and neck cancer. Inaccuracies in radiation targeting are responsible for incidental exposure of healthy adjacent tissues, causing significant morbidity and mortality. This paper focuses on inaccuracies incurred when a tumor is displaced during treatment. To address this problem, the clinical target must be expanded to cover the region through which the tumor might move. The resulting expanded target is known as the Planning Target Volume (PTV). In the current practice, the rotational components of displacements are neglected, producing planning target volumes that either miss the true target motion or are larger than needed to cover the target path. By using the dual quaternion based kinematic formulation, this paper represents and captures both translational and rotational inaccuracies. It then presents a framework for calculating the PTV swept out by the target as it shifts within its range of translations and rotations.

Research on autonomous vehicle path tracking control considering roll stability

For autonomous vehicle path tracking control, the general path tracking controllers usually only consider vehicle dynamics’ constraints, without taking vehicle stability evaluation index into account. In this paper, a linear three-degree-of-freedom vehicle dynamics model is used as a predictive model. A comprehensive control method combining Model Predictive Control and Fuzzy proportional–integral–derivative control is proposed. Model Predictive Control is used to control the vehicle yaw stability and track the target path by considering the front wheel angle, sideslip angle, tire slip angles, and yaw rate during the path tracking. Fuzzy proportional–integral–derivative algorithm is adopted to maintain the vehicle roll stability by controlling the braking force of each tire. Co-simulation with CarSim and MATLAB/Simulink shows the designed controller has good tracking performance. The controller is smooth and effective and ensures handling stability in tracking the target path.

Segment-Resolved Gas Concentration Measurements by a Time Domain Multiplexed Dual Comb Method

Locating gas concentration changes in widespread locations can be conducive to environmental atmospheric detection, gas emissions monitoring, production process control, etc. A time domain multiplexed dual-comb system for segment-resolved gas concentration measurement is reported in this work. Both absorption spectra and path lengths for multiple path-segments in a target path can be derived from the time domain separated interferograms and then the equivalent gas concentrations in each segment can be retrieved separately. A benchtop experiment aiming at a target path with three path-segments of different gases has been demonstrated. The relative deviation of gas concentration retrieval is 1.08% in 1 s. Besides, additional numerical simulations prove that the crosstalk between the interference signals affects the spectrum analysis by no more than 0.1% for a kilometer-long atmospheric absorption detection. Therefore, achieving a gridded measurement of regional gas concentration in the open air can be foreseen using this method.

Motion-Assist Arm with a Passive Joint for an Upper Limb

This study proposes a motion-assist arm that can accurately support the positioning of a human upper limb. The motion-assist arm is a three-degree-of-freedom (DOF) planer under-actuated robotic arm with a 1-DOF passive joint that can be driven by an human. A control method for the robot arm is as follows. First, when the human moves an output point of the arm manually, the passive joint is rotated with the movement of the output point. Then, for accurate positioning of the output point on a target path, the actuated joints are controlled according to the displacement of the passive joint. Based on the above method, the human can adjust the velocity of the output point deliberately while its position is accurately corrected by the actuated joints. To confirm its effectiveness, the authors conducted tests to assist the human’s upper limb movement along straight target paths, a square path, and free curves paths such as italic letters with the proposed robot arm prototype. From the results of the tests, the authors confirmed that the proposed robot arm can accurately position the upper limb of the human on the target paths while the human intentionally moves the upper limb. It is expected that the proposed arm will be used for rehabilitation because it can aid patients to move their arms correctly. In addition, the proposed arm will enable any human to achieve complex work easily.