Lateral guidance control of a low-speed vehicle

This thesis examines the lateral guidance control of a low-speed vehicle. Several topics are studied in detail: (1) vehicle error-state model for lateral guidance based on Ackerman steering and (2) lateral guidance control of a low-speed vehicle using fuzzy logic. Independently written research papers address each topic. The first paper presents a second order error-state kinematic model based on Ackerman steering appropriate for studying the lateral guidance control of low-speed vehicles traversing on roads of constant curvature. Lateral guidance control of vehicles is of great interest to the Advanced Vehicle Control Systems (AVCS) Division of the Intelligent Transportation System (ITS) community. Both linear and nonlinear models are derived in detail. The error states considered are the vehicle\u27s lateral error and heading error measured with respect to the instantaneous road centerline tangent. In addition to the derivation, both simulation and experimental results are presented with very good correspondence being achieved. The second paper investigates the performance of several different controllers used to perform lateral guidance control of a low-speed vehicle described as a linear nonminimum-phase error-state bicycle model based on Ackerman steering. Both a conventional type I proportional-integral (PI) controller and a fuzzy logic controller (FLC) are considered. The PI controller is designed using standard techniques and the two-level FLC / PI controller adjusts both proportional and integral feedback control gains around the baseline values based on heuristics and the current conditions as measured by the lateral error. Time-based simulations using MATLAB / SIMULINK permit a comparison between both controllers for several different simulation scenarios of interest. Primary performance metrics considered were percent overshoot and settling time in response to a step input. In general, the two-level FLC / PI controller performed better; 6 % reduction in overshoot and 21 % reduction in settling time

Robot grasping and regrasping kinematics using Lie algebra, the geodesic, and Riemann curvature tensor

Differential geometry is a strong and highly effective mathematical subject for robot gripper design when grasping within the predetermined trajectories of path planning. This study in grasping focuses on differential geometry analysis utilizing the Lie algebra, geodesic, and Riemann Curvature Tensors (RCT). The novelty of this article for 2RR robot mechanisms lies in the approach of the body coordinate with the geodesic and RCT. The importance of this research is significant especially in grasping and regrasping objects with varied shapes. In this article, the types of workspaces are clarified and classified for grasping and regrasping kinematics. The regrasp has not been sufficiently investigated of body coordinate systems in Lie algebra. The reason for this is the difficulty in understanding relative coordinates in Lie algebra via the body coordinate system. The complexity of the equations has not allowed many researchers to overcome this challenge. The symbolic mathematics toolbox in the Maxima, on the other hand, aided in the systematic formulation of the workspaces in Lie algebra with geodesic and RCT. The Lie algebra se(3) equations presented here have already been developed for robot kinematics from many references. These equations will be used to derive the followingworkspace types for grasping and regrasping. Body coordinate workspace, spatial coordinate workspace with constraints, body coordinate workspace with constraints, spatial coordinate workspace with constraints are the workspace types. The RCT and geodesic solutions exploit these four fundamental workspace equations derived using Lie algebra

The Modular Nonoverlapping Grasp Workspaces and Dynamics for the Grippers using the Micro and Macro C-Manifold Design

The toolbox for the gripper workspace analyses using Lie algebra is developed for shape variables (α1-4 − θ1,2) of the skew revolute joints. The unique methodology for grippers comprises to enable the variety of manifold analyses for kinematics and dynamics using symbolic mathematics. The Controllable Instantaneous Screw Axes (C-ISA) are defined through the shape variables considering the twists of the skew revolute joints se(3). The derivation and analyses of the kinematics and dynamics equations are made possible using the developed methodology with the defined constraints for gripper mechanisms. The Modular Gripper with Lie Algebra Toolbox (M-GLAT) is developed for the defined constraints of the angle between C-ISA 1 and C-ISA 2. The novelty subject of this article is the development of the M-GLAT method for derivation of the constraint based workspaces with the shape variables (α1-4 − θ1,2) in the field of the spatial 2-RR gripper mechanisms. The gripper dynamics with constraint based workspaces of the skew revolute joints are developed for varied configurations of α1-4 with ICs of θ1,2. The modular rule-based workspaces are analyzed for the shape variables of the (α1‑4 − θ1,2) with the task spaces. This design produces dexterity with the modular grasp workspaces for the gripper fingers with skew revolute joints. One can select a combination of C-manifolds of (π/20, π/40, π/80) for the requirement of the nonoverlapping workspaces of the gripper finger designs as the grasp surfaces to control.  The modular nonoverlapping workspace design with dynamics herein is based on the shape variables (α1-4 − θ1,2) using skew revolute joint which produce the high dexterity for the grasping capability of the grippers. The modular micro and macro C-manifold designs obtained the constraint based workspace algorithms of the 2-RR gripper which is expandable into the higher modular revolute joints of the n-R for the grippers. The n-R modular expandable grippers are increasing the precision and power grasping capability

Impedance responses and size-dependent resonances in topolectrical circuits via the method of images

Resonances in an electric circuit occur when capacitive and inductive components are present together. Such resonances appear in admittance measurements depending on the circuit's parameters and the driving AC frequency. In this study, we analyze the impedance characteristics of nontrivial topolectrical circuits such as one- and two-dimensional Su-Schrieffer-Heeger circuits and reveal that size-dependent anomalous impedance resonances inevitably arise in finite $LC$ circuits. Through the \textit{method of images}, we study how resonance modes in a multi-dimensional circuit array can be nontrivially modified by the reflection and interference of current from the structure and boundaries of the lattice. We derive analytic expressions for the impedance across two corner nodes of various lattice networks with homogeneous and heterogeneous circuit elements. We also derive the irregular dependency of the impedance resonance on the lattice size, and provide integral and dimensionally-reduced expressions for the impedance in three dimensions and above.Comment: 24 pages, 10 figure

Effective detection of proteins following electrophoresis using extracts of locally available food species

Procedures in life sciences research laboratories often require chemicals and plasticware that are costly, toxic or pose a risk to the environment. Therefore, sustainable alternatives would be of interest, provided that they generate suitable data quality. Coomassie blue and silver staining are the most widely used methods for detecting proteins following electrophoresis in the laboratory. However, their use presents challenges in terms of safety and waste management. In the current study, aqueous extracts were prepared from a series of common food species and evaluated as alternative stains for protein detection. Beets, blueberries, purple cabbage, raspberries and strawberries were employed to stain identical proteins separated under the same conditions in electrophoresis gels. Extracts of the first two species resulted in protein bands that were detectable through visible light transillumination, whereas extracts from all five species generated specific protein bands under ultraviolet light. The raspberry-derived extract was selected for further study based on the brightness of the fluorescent protein bands and minimal background staining. For both bovine serum albumin and lysozyme at 2.5 μg and 0.5 μg protein per band, the mean signal intensities obtained with raspberry extract staining were just below half of those obtained with Coomassie blue. Furthermore, the mean intensities using raspberry extract were equivalent to those obtained using Coomassie blue in the detection of 0.1 μg protein. Therefore, raspberry could be used to produce an effective stain for the routine laboratory analysis of proteins

Robot grasping and regrasping kinematics using Lie algebra, the geodesic, and Riemann curvature tensor

Differential geometry is a strong and highly effective mathematical subject for robot gripper design when grasping within the predetermined trajectories of path planning. This study in grasping focuses on differential geometry analysis utilizing the Lie algebra, geodesic, and Riemann Curvature Tensors (RCT). The novelty of this article for 2RR robot mechanisms lies in the approach of the body coordinate with the geodesic and RCT. The importance of this research is significant especially in grasping and regrasping objects with varied shapes. In this article, the types of workspaces are clarified and classified for grasping and regrasping kinematics. The regrasp has not been sufficiently investigated of body coordinate systems in Lie algebra. The reason for this is the difficulty in understanding relative coordinates in Lie algebra via the body coordinate system. The complexity of the equations has not allowed many researchers to overcome this challenge. The symbolic mathematics toolbox in the Maxima, on the other hand, aided in the systematic formulation of the workspaces in Lie algebra with geodesic and RCT. The Lie algebra se(3) equations presented here have already been developed for robot kinematics from many references. These equations will be used to derive the following workspace types for grasping and regrasping. Body coordinate workspace, spatial coordinate workspace with constraints, body coordinate workspace with constraints, spatial coordinate workspace with constraints are the workspace types. The RCT and geodesic solutions exploit these four fundamental workspace equations derived using Lie algebra

Evaluation of marginal adaptation in three-unit frameworks fabricated with conventional and powder-free digital impression techniques

PURPOSE. The purpose of this in vitro study was to evaluate the marginal misfits three-unit frameworks fabricated with conventional and digital impressions techniques. MATERIALS AND METHODS. Thirty brass canine and second premolar abutment preparations were fabricated by using a computer numerical control machine and were randomly divided into 3 groups (n=10) as follows: conventional impression group (Group Ci), Cerec Omnicam (Group Cdi), and 3shape TRIOS-3 (Group Tdi) digital impression groups. The laser-sintered metal frameworks were designed and fabricated with conventional and digital impressions. The marginal adaptation was assessed with a stereomicroscope at x30 magnification. The data were analyzed with 1-way analysis of variances (ANOVAs) and the independent simple t tests. RESULTS. A statistically significant difference was found between the frameworks fabricated by conventional methods and those fabricated by digital impression methods. Multiple comparison results revealed that the frameworks in Group Ci (average, 98.8 +/- 16.43 mu m; canine, 93.59 +/- 16.82 mu m; premolar, 104.10 +/- 15.02 mu m) had larger marginal misfit values than those in Group Cdi (average, 63.78 +/- 14.05 mu m; canine, 62.73 +/- 13.71 mu m; premolar, 64.84 +/- 15.06 mu m) and Group Tdi (average, 65.14 +/- 18.05 mu m; canine, 70.64 +/- 19.02 mu m; premolar, 59.64 +/- 16.10 mu m) (P=.000 for average; P=.001 for canine; P.05). CONCLUSION. The three-unit frameworks fabricated with digital impression techniques showed better marginal fit compared to conventional impression techniques. All marginal misfit values were clinically acceptable

Additively Manufactured Custom Soft Gripper with Embedded Soft Force Sensors for an Industrial Robot

Soft robotic grippers are required for power grasping of objects without inducing damage. Additive manufacturing can be used to produce custom-made grippers for industrial robots, in which soft joints and links are additively manufactured. In this study, a monoblock soft robotic gripper having three geometrically gradient fingers with soft sensors was designed and additively manufactured for the power grasping of spherical objects. The monoblock structure design reduces the number of components to be assembled for the soft gripper, and the gripper is designed with a single cavity to enable bending by the application of pneumatic pressure, which is required for the desired actuation. Finite element analysis (FEA) using a hyperelastic material model was performed to simulate the actuation. A material extrusion process using a thermoplastic polyurethane (TPU) was used to manufacture the designed gripper. Soft sensors were produced by a screen printing process that uses a flexible material and ionic liquids. The grasping capability of the manufactured gripper was experimentally evaluated by changing the pneumatic pressure (0-0.7 MPa) of the cavity. Experimental results show that the proposed monoblock gripper with integrated soft sensors successfully performed real-time grasp detection for power grasping

Examining the relationship between symptoms watched in lung cancer patients and illness perception

Objective: To examine the relationship between the symptom experience of lung cancer patients and their illness perception of the disease. Methods: The descriptive and cross-sectional study was conducted from April to September 2015 at the Chemotherapy Treatment Centre of the Medicine Chest Diseases Clinic at the Ege University, Izmir, Turkey, and comprised lung cancer patients of either gender aged >18 years. Data was collected using a predesigned Patient Questionnaire as well as the standard Lung Cancer Symptom Scale, Illness Perception Questionnaire and Karnofsky Performance Scale. The patients' sociodemographic characteristics and data on their illness, the symptoms they experienced and the numerical and percentage distribution of the items on the illness perception scale, mean and standard deviation values were examined. Pearson Correlation analysis was used to examine the correlation between illness perception and Karnofsky Performance Scale scores and other variables. Results: Of the 105 patients, 86(81.9%) were males, 86(81.9%) were married, 49(46.7%) were elementary school graduates, 101(96.2%) were unemployed, and 95(90.5%) were receiving chemotherapy. The overall mean age of the sample was 61.43 +/- 8.24 years, the period since diagnosis was 11.38 +/- 17.84 months, and the duration of chemotherapy was 4.28 +/- 2.37 months. The mean symptom burden score was 22.75 +/- 10.85 and the Lung Cancer Symptom Scale score was 22.75 +/- 10.85. The mean score of the type of illness domain was 5.53 +/- 2.12. The overall mean global quality of life score was 64.30 +/- 12.60. Conclusions: As the symptom burden experienced by the lung cancer patients increased, their perception of the illness became more negative, and the longer the cyclical periods and the period of diagnosis, the patients' control over their illness decreased