Orientation Accuracy Research Articles

Cortical Integration of Vestibular and Visual Cues for Navigation, Visual Processing, and Perception.

Despite increasing evidence of its involvement in several key functions of the cerebral cortex, the vestibular sense rarely enters our consciousness. Indeed, the extent to which these internal signals are incorporated within cortical sensory representation and how they might be relied upon for sensory-driven decision-making, during, for example, spatial navigation, is yet to be understood. Recent novel experimental approaches in rodents have probed both the physiological and behavioral significance of vestibular signals and indicate that their widespread integration with vision improves both the cortical representation and perceptual accuracy of self-motion and orientation. Here, we summarize these recent findings with a focus on cortical circuits involved in visual perception and spatial navigation and highlight the major remaining knowledge gaps. We suggest that vestibulo-visual integration reflects a process of constant updating regarding the status of self-motion, and access to such information by the cortex is used for sensory perception and predictions that may be implemented for rapid, navigation-related decision-making.

Стабилизирующая активная подвеска вращающейся антенны аэростатной радиолокационной станции

The paper considers the problem of the precision accurate angular orientation and stabilization of the radar station rotating antenna suspended from the tethered balloon and exposed to external vibrational influences capable of leading to significant amplitudes of the low-frequency oscillations in roll and pitch (±15°) at the angular velocity of 10 s-1. Analysis of the known solutions to this problem demonstrated that they all were reduced to the aerostat stabilizers in the form of the tail assembly, as well as to using passive or active stabilizing suspensions. It was noted that gimbal or other suspension with formation of a physical pendulum was used in passive suspensions that were unable to meet modern requirements for accuracy of orientation and stabilization of the rotation axis of the aerostat radar antenna (no more than 6’). Additional use of the servo drives with the self-braking mechanical gears or introduction of the active suspension based on a tripod in combination with the pendulum suspension would inevitably lead to an increase in mass, energy consumption and cost. Possibility of solving this problem is shown on the example of a stabilizing active suspension constructed using the pneumatic automation system elements. A stabilizing active suspension for the rotating antenna of an aerostat radar station is proposed. The proposed suspension is universal and could be used in other areas, for example, in lifting and transport systems designed to work with the objects of increased hazard, as well as in precise installation works in the hard-to-reach locations, for example, with using helicopters or high-altitude cranes.

Camera-Aided Orientation of Mobile Lidar Point Clouds Acquired from an Uncrewed Water Vehicle.

This article presents a system for recording 3D point clouds of riverbanks with a mobile lidar mounted on an uncrewed water vehicle. The focus is on the orientation of the platform and the lidar sensor. Rivers are areas where the conditions for highly accurate GNSS can be sub-optimal due to multipath effects from the water and shadowing effects by bridges, steep valleys, trees, or other objects at the riverbanks. Furthermore, a small measurement platform may have an effect on the accuracy of orientations measured by an IMU; for instance, caused by electromagnetic fields emitted by the boat rotors, the lidar, and other hardware decreasing IMU accuracy. As an alternative, we use exterior orientation parameters obtained by photogrammetric methods from the images of a camera on the boat capturing the riverbanks in time-lapse mode. Using control points and tie points on the riverbanks enables georeferenced position and orientation determination from the image data, which can then be used to transform the lidar data into a global coordinate system. The main influences on the accuracy of the camera orientations are the distance to the riverbanks, the size of the banks, and the amount of vegetation on them. Moreover, the quality of the camera orientation-based lidar point cloud also depends on the time synchronization of camera and lidar. The paper describes the data processing steps for the geometric lidar-camera integration and delivers a validation of the accuracy potential. For quality assessment of a point cloud acquired with the described method, a comparison with terrestrial laser scanning has been carried out.

THE EVALUATION OF STRUCTURE-FROM-MOTION WORKFLOW WITH THE TLS SYNTHETIC IMAGES SIMULATOR – THE CULTURAL HERITAGE APPROACH

Abstract. Modern measurement technologies such as Terrestrial Laser Scanning or combined Structure-from-Motion with Multi-View Stereo are commonly utilised to monitor, preserve and document cultural heritage objects and sites. For this reason, it is essential to know the capabilities and limitations of the sensor used, the data processing methods, and in particular, the orientation of the images. However, these algorithms tackle different errors and have different effects on the final accuracy of images orientation. For this reason, it is essential to know how the algorithms implemented in the Structure-from-Motion approach work. Due to the impossibility of obtaining this information for commercial solutions, it is necessary to use synthetic data to assess the quality of the SfM process. Therefore, this article aims to present the method of evaluation of SfM approach implemented in commercial Agisoft Metashape and COLLMAP open-source software based on the synthetic data generated from TLS point clouds of three different Cultural Heritage sites. In addition, obtained results were compared with the author's SfM approach based on BRISK, FAST, CenSurE, SIFT and SURF (and its Affine detectors equivalents) detector implemented (Fig. 1) and Learned-based -feature extraction approach SuperGlue and LoFTR. The second aim of this research is to propose an application to automatically generate scalable benchmark based on point clouds or 3D models of cultural heritage objects.

ROBOTIC ARM-ASSISTED SYSTEM IMPROVED ACCURACY OF CUP POSITION AND ORIENTATION IN CEMENTLESS TOTAL HIP ARTHROPLASTY FOR DYSPLASTIC HIPS: COMPARISON AMONG THE GROUPS WITH MANUAL PLACEMENT, CT-BASED NAVIGATION, AND ROBOTIC SURGERY

Accurate cup placement in total hip arthroplasty (THA) for the patients with developmental dysplasia of the hip (DDH) is one of the challenges due to distinctive bone deformity. Robotic-arm assisted system have been developed to improve the accuracy of implant placement. This study aimed to compare the accuracy of robotic-arm assisted (Robo-THA), CT-based navigated (Navi-THA), and manual (M-THA) cup position and orientation in THA for DDH.A total of 285 patients (335 hips) including 202 M-THAs, 45 Navi-THAs, and 88 Robo-THA were analyzed. The choice of procedure followed the patient's preferences. Horizontal and vertical center of rotation (HCOR and VCOR) were measured for cup position, and radiographic inclination (RI) and anteversion (RA) were measured for cup orientation. The propensity score-matching was performed among three groups to compare the absolute error from the preoperative target position and angle.Navi-THA showed significantly smaller absolute errors than M-THA in RI (3.6° and 5.4°) and RA (3.8° and 6.0°), however, there were no significant differences between them in HCOR (2.5 mm and 3.0 mm) or VCOR (2.2 mm and 2.6 mm). In contrast, Robo-THA showed significantly smaller absolute errors of cup position than both M-THA and Navi-THA (HCOR: 1.7 mm and 2.9 mm, vs. M-THA, 1.6 mm and 2.5 mm vs. Navi-THA, VCOR:1.7 mm and 2.4 mm, vs. M-THA, 1.4 mm and 2.2 mm vs. Navi-THA). Robo-THA also showed significantly smaller absolute errors of cup orientation than both M-THA and Navi-THA (RI: 1.4° and 5.7°, vs. M-THA, 1.5° and 3.6°, vs. Navi-THA, RA: 1.9° and 5.8° vs. M-THA, 2.1° and 3.8° vs. Navi-THA).Robotic-arm assisted system showed more accurate cup position and orientation compared to manual and CT-based navigation in THA for DDH. CT-based navigation increased the accuracy of cup orientation compared to manual procedures, but not cup position.

Research on the close-range photogrammetry accuracy of 3D digital interactive platform of Hunan intangible cultural heritage

Abstract This paper designed a three-dimensional digital interactive platform, which takes power supply module, image data acquisition module, control module, data transmission module and ESAM module as the main hardware and makes it feasible to realize power supply transmission, multiple data acquisition, platform process control, data transmission, data encryption and decryption, and identity authentication. Then, through relative orientation element calculation, model point coordinate calculation, relative orientation model proportion coefficient calculation, relative orientation model deformation accuracy calculation, and relative orientation accuracy calculation, this paper realized the relative control of close-range photogrammetry, improving the accuracy of close-range photogrammetry. The results show that the relative control method of close-range photogrammetry studied in this paper can increase the relative accuracy from 319 to 769 and improve the average value of the relative orientation model deformation accuracy from 0.4282 to 0.5938. In addition, in performance analysis, the response time of the platform is 0.32s, the accuracy of close-range photogrammetry is 96.3%, and the comprehensiveness of data detection is 94.37%. Therefore, it is concluded that using the method proposed in this paper, the relative orientation model deformation accuracy is increased, the accuracy of close-range photogrammetry is the highest, and the data detection is more comprehensive.

Observability Analysis and Optimization of Cooperative Navigation System With a Low-Cost Inertial Sensor Array

Low-cost inertial measurement unit (IMU) is gradually applied for providing reliable positioning and navigation information in the area of Internet of Things (IoT) applications recently. However, the accuracy of IMU is highly influenced by inertial sensor errors in GNSS-denied and indoor navigation environment. In order to improve the accuracy and robustness of IMU, rotation modulation and cooperative navigation techniques can serve as effective ways for indoor and outdoor seamless navigation and positioning. In this paper, we propose a cooperative navigation system with a low-cost inertial sensor array composed of four IMUs. For optimizing the configuration and information processing of this system, observability analysis is carried out based on the concept of the degree of observability. Furthermore, a criterion for calculating the degree of observability is formulated to simplify the observability analysis of rotational IMUs. According to the simulation experiments of unmanned vehicle at low, medium and high driving speeds, the IMU rotation technique can improve the observability of inertial sensor errors and thus increase the accuracy of orientation, while the cooperative navigation technique can highly improve the accuracy of positioning.

METHODOLOGY TO IMPROVE THE ACCURACY OF DETERMINING THE POSITION OF UAVS EQUIPPED WITH SINGLE-FREQUENCY RECEIVERS FOR THE PURPOSES OF GATHERING DATA ON AVIATION OBSTACLES

Low-altitude photogrammetric studies are often applied in detection of aviation obstacles. The low altitude of the Unmanned Aerial Vehicle (UAV) flight guarantees high spatial resolution (X, Y) of the obtained data. At the same time, due to high temporal resolution, UAVs have become an appropriate tool for gathering data about such obstacles. In order to ensure the required accuracy of orientation of the photogrammetric block, Ground Control Points (GCPs) are measured. The recently introduced UAV positioning solutions that are based on Post-Processing Kinematic (PPK) and Real Time Kinematic (RTK) are known to effectively reduce, or, according to other sources, even completely eliminate the necessity to conduct GCP measurements. However, the RTK method involves multiple limitations that result from the need to ensure continuous communication between the reference station and the rover receiver. The main challenge lies in achieving accurate orientation of the block without the need to conduct time-consuming ground measurements that are connected to signalling and measuring the GCPs. Such solution is required if the SPP code method is applied to designation the position of the UAV. The paper presents a research experiment aimed at improving the accuracy of the determination of the coordinates of UAV for the SPP method, in real time. The algorithm of the SPP method was improved with the use of IGS products.

Autonomous Respiratory Motion Compensated Robot for CT-Guided Abdominal Radiofrequency Ablations

Radiofrequency ablation (RFA) is an effective minimally-invasive treatment used for a variety of solid tumor cancers, including lung, breast, kidney, pancreatic, and liver. However, effective RFA for abdominal tumors relies on accurate ablation needle targeting, which can be a challenging task due to respiratory motion. This paper presents the design, fabrication, modeling, and benchtop characterization of a CT-guided parallel robot, and a novel respiration motion compensation protocol (RMCP) for effective robot-assisted abdominal RFA needle placement. The robot consists of a Stewart platform with a friction drive roller insertion module for autonomous needle deployment. Strain energy models are used to predict needle insertion force, the primary technical contribution of this work, providing a mean error of 0.49±0.28 N. The free-space accuracy characterization experiments indicate that the robotic platform is able to provide a needle tip position and orientation accuracy of 2.00±0.75 mm and 0.81±0.48±, respectively. A dynamic targeting experiment using an ex-vivo liver indicates an improvement in position and orientation error of 57% and 30%, respectively, when using the proposed RMCP. Finally, an animal study using a sexually-mature swine undergoing assisted respiration at nine breaths per minute indicates a 77% reduction in additional insertion displacement when using the RMCP.

An effective approach for non-singular trajectory generation of a 5-DOF hybrid machining robot

By taking a newly developed 5-DOF (degree of freedom) hybrid robot as an exemplar, this paper presents a novel and effective approach for non-singular tool trajectory generation. Based upon singularity analysis via inverse kinematics, an algorithm for the C-axis path optimization is developed using the weighted S-curve. Incorporated singular domain detection with the C-axis angle correction, the algorithm can easily be programmed and embedded into the CNC (computer numerical control) system as a postprocessing module and works in real-time. Then, an offline feedrate scheduling method is proposed by considering the drive and geometric accuracy constraints, allowing the rapid yet smooth movement in the neighborhood of singularity to be achieved. Additionally, it is found that the orientation accuracy can be improved by setting adequate cone angle and feedrate value. The results of both simulations and experiments on a prototype machine show that the C-axis can follow the non-singular tool trajectory well with relatively high rotary speed to pass through the singular domain, thereby verifying the effectiveness of the proposed approach.

Kinematic Calibration of a Space Manipulator Based on Visual Measurement System with Extended Kalman Filter

The calibration of kinematic parameters has been widely used to improve the pose (position and orientation) accuracy of the robot arm. Intelligent measuring equipment with high accuracy is usually provided for the industrial manipulator. Unfortunately, large noise exists in the vision measurement system, which is provided for space manipulators. To overcome the adverse effect of measuring noise and improve the optimality of calibrating time, a calibration method based on extended Kalman filter (EKF) for space manipulators is proposed in this paper. Firstly, the identification model based on the Denavit–Hartenberg (D-H) modeling method is established. Then, the camera which is rigidly attached to the end-effector takes pictures of a calibration board that is settled around the manipulator. The actual pose of the end-effector is calculated based on the pictures of the calibration board. Subsequently, different data between the actual pose and theoretical pose as input, whilst error parameters are estimated by EKF and compensated in the kinematic algorithm. The simulation result shows that the pose accuracy has been improved by approximately 90 percent. Compared with the calibration method of the least squares estimate (LSE), EKF is beneficial to further optimize the calibrating time with a faster computation speed and ensure the stability of the calibration.

Extension of the Application Range of Multipolar Bonded Ring Magnets by Thermosets in Comparison to Thermoplastics

To expand the range of applications of multipolar bonded magnets based on a thermoplastic matrix, the chemical and thermal resistance has to be increased and the reduced orientation in the rapid solidified surface layer has to be overcome. To meet these requirements, the matrix of multipolar bonded magnets can be based on thermosets. This paper investigates in the magnetic properties, especially in the orientation of hard magnetic fillers, the pole accuracy and the mechanical properties of multipolar bonded ring magnets based on the hard magnetic filler strontium-ferrite-oxide and compares the possibilities of thermoplastic (polyamide)- and thermoset (epoxy resin, phenolic resin)-based matrices. It was shown that the magnetic potential of the thermoset-based material can only be fully used with further magnetization. However, the magnetic properties can be increased using thermoset-based compounds compared to thermoplastics in multipolar bonded ring magnets. Further, a model of the orientation and pole accuracy is found in terms of thermoset-based multipolar magnets. In addition, the change of the mechanical properties due to the different matrix systems was shown, with an increase in E-Modulus, Et, and a reduction in tensile strength, σm, and elongation at break, εm, in terms of thermosets compared to thermoplastics.

Robust Orientation Method Based on Atmospheric Polarization Model for Complex Weather

Accurate and reliable navigation data is a key component in Internet of Things (IoT). High-precision and stable autonomous orientation has attracted considerable attention regarding environments in which the global navigation satellite system signal is unreliable. This study proposed a robust orientation method based on the atmospheric polarization mode called weather weighting sparse coding that includes weather classification, sparse coding, and fitting. In comparison with previous studies, the proposed method is effective in restoring the angle-of-polarization image and achieving accurate orientation under complex weather. Specifically, to achieve high-precision orientation in complex weather, a polarization compass was designed, which used the characteristics of the different levels of destruction of atmospheric polarization images under different weather conditions for classification and denoising. The proposed strategy was used to process atmospheric polarization images obtained in complex weather. Experimental results showed that the orientation accuracy was better than 0.31° (root-mean-square error) under conditions of overcast, sandstorms, clear with overexposed areas, and smog with tree-obscured and overexposed areas.

Online deep Bingham network for probabilistic orientation estimation

AbstractOrientation estimation is one of the core problems in several computer vision tasks. Recently deep learning techniques combined with the Bingham distribution have attracted considerable interest towards this problem when considering ambiguities and rotational symmetries of objects. However, existing works suffer from two issues. First, the computational overhead for calculating the normalisation constant of the Bingham distribution is relatively high. Second, the choice of loss functions is uncertain. In light of these problems, we present an online deep Bingham network to estimate the orientation of objects. We sharply reduce the computational overhead of the normalisation constant by directly applying a numerical integration formula. Additionally, we are the first to give theorems on the convexity and Lipschitz continuity of the Bingham distribution's negative log‐likelihood, which formally indicates that it is a proper choice of the loss function. We test our method on three public datasets, namely the UPNA, the T‐LESS and Pascal3D+, showing that our method outperforms the state‐of‐the‐art in terms of orientation accuracy and time efficiency, which can reduce the runtime by more than 6 h compared to the offline methods. The ablation experiments further demonstrate the effectiveness and robustness of our model.

Five-degree-of-freedom robust control of a magnetic endoscopic capsule using an electromagnetic system

Capsule endoscopy is a minimally invasive gastrointestinal diagnostic procedure. The active endoscopic capsule enables the physician to steer the device to any desired position and direction, resulting in a better diagnosis of the disease. Due to the model uncertainties and the existence of disturbances in the gastrointestinal system, traditional control methods cannot achieve robust performance and stability. To overcome this issue, in this paper, a robust sliding mode controller is proposed for 5 Degrees Of Freedom (DOF) control (3-DOF closed-loop control for position and 2-DOF open-loop control for orientation) of the capsule endoscope using an electromagnetic actuation system. The efficiency of the proposed control method is compared with a Proportional–Integral–Derivative (PID) controller considering the model uncertainties and external disturbances. The results of simulations considering 5% of uncertainty in the model parameters show that the suggested approach can precisely and efficiently actuate the capsule to follow the desired trajectory, with position and orientation accuracy of 0.53 mm and 0.69 degree, respectively. Experiments demonstrate the efficiency of the proposed controller, revealing a tracking error of about 0.73 mm in the capsule position. Furthermore, it has been proven by experiments that even in the presence of external disturbances, the proposed control system performs very well and keeps the capsule on the desired trajectory.

Подход к снижению виброактивности малых космических аппаратов

Flawless spacecraft operation and successful implementtation of their research in orbit mainly depend on technical and operational characteristics of the spacecraft orientation and stabilization control systems in space relative to the base frame of reference axes achieved through stabilizing properties of certain external and internal perturbations. The research was aimed at determining static and dynamic imbalances and analyzed the levels of influence of forces and moments created by non-contact electric motor-flywheel operating at the various rotor speeds. In order to reduce the static and dynamic imbalance of the non-contact electric motor-flywheel obtained as a result of ongoing experimental studies, it was proposed to introduce a vibration isolator with natural frequency significantly lower than that in the conventional systems in order to statically hold the non-contact electric motor-flywheel during ground and flight operation. The vibration isolator should have small mass and rigidity, as well as a wide range of operating temperatures, etc. Depending on the orbit altitude, the moments of external disturbing forces acting on the Iskra-5 spacecraft were determined. Electric DC motor-flywheels of various types were analyzed. It was shown that introduction of the non-contact electric motor-flywheel as the executive element of the orientation and stabilization control systems on small spacecraft improved the orientation accuracy. Ways to reduce the effect of vibration disturbances on the spacecraft structure from the non-contact electric motor-flywheel were considered

Contemporary, non-navigation, cup orientation techniques improve accuracy and eliminate differences seen between the anterior and posterior approach in THA.

This study aimed to: (1) Determine the ability to achieve the surgeons' desired cup orientation, without navigation, using contemporary measures with the anterior- (AA) and posterior- approaches (PA); and (2) assess whether surgical approach is associated with cup orientation accuracy, as previously reported, when contemporary measures are used. A prospective, 2-centre, multi-surgeon study of 400 THAs (200 AA; 200 PA) was performed. Intraoperative radiographs were obtained with the AA. A digital inclinometer and 3-point pelvic support were used with the PA. With the PA, intraoperative cup inclination at impaction was recorded. Radiographic inclination/anteversion (RI/RA) was measured from intraoperative radiographs (AA-only) and from postoperative radiographs for all cases. Optimum inclination/anteversion was defined as 40°/20° (±10°). The difference between intra- and postoperative orientations allowed for determination of the difference in pelvic position at impaction. Optimum RI and RA were achieved in 91.3% (n = 365) and 92% (n = 368) of cases respectively. Optimum cup orientation was detected in 84% of cases (n = 336). There was equivalent ability to achieve cup orientation between approaches (AA: 82.5% vs. PA: 85.5%; p = 0.41). The use of an inclinometer in the PA was associated with a smaller variability of inclination at implantation (10° vs. 14°) and counteracted the greater difference in pelvic position (4.4° vs. 2.1°) seen with the PA. Over 80% of cases can have optimum orientation without navigation, using simple, cheap contemporary measures. Such measures eliminate differences between approaches, related to patient position. Narrower implantation angles will further reduce variability in cup orientation achieved.

Joint space-based optimal measurement configuration determination method for Stewart platform kinematics calibration

The accuracy problem is one of the most concerning problems for the industrial application of a Stewart platform, and kinematic calibration is a feasible way to solve it. Although various calibration methods have been proposed, there is still room for improvement in the accuracy and robustness of these studies. In this article, a dimensionless error model is investigated, and the kinematic parame-ter errors are identified via the least-square method. Moreover, a novel method for measurement configurations selected based on the joint space is proposed. The simulation results show that the identification accuracy of the proposed method is better than that of the conventional method whose measurement configurations are uniformly selected in the workspace. A measurement method of the calibration experiment is suggested by the AICON 3D system - MoveInspect XR. The experimental results indicate that the position and orientation accuracy of the proposed method enhanced by 5% and 11% relative to the uniform selection method.

Diagnostic Accuracy of CHROMagar Orientation for Identification of Uropathogens

Objective: To determine the diagnostic accuracy of CHROMagar Orientation for its ability to support the growth and identification of uropathogens by keeping API 20E/20NE as a gold standard.
 Study Design: Cross-sectional study.
 Place and Duration of Study: Department of Microbiology, Armed Forces Institute of Pathology, Rawalpindi Pakistan, from Jun to Nov 2019.
 Methodology: A total of 470 midstream specimen of urine from patients suspected of UTIs were analyzed. Urine specimens were inoculated by 1µL calibrated sterilized loop each on CLED Agar, Blood agar and CHROMagar Orientation media plates.Culture plates were incubated at 35.00±2.00ºC for 18 to 24 hours. As per standard protocols, isolates were identified by colony morphology, Gram stain, catalase, oxidase, DNAase, coagulase, and API 20E/20NE. In addition, the appearance of microorganism on CHROMagar Orientation media were identified according to the manufacturer’s instructions.
 Results: Out of 470 samples, 211 showed no growth, 90 were classified as mix growth (polymicrobial), and 169 samples were positive (unimicrobial) for the growth of uropathogens. All the samples positive for bacterial growth on conventional media were also positive on CHROMagar orientation and vice versa. The sensitivity and specificity of CHROMagar Orientation for differentiation of uropathogens were 99% and 100%, respectively.
 Conclusion: The overall findings of our study suggested that CHROMagar supports the growth of all uropathogens. It provided the rapid identification of organisms based on their colour morphology, even in a mixed bacterial culture, growth within 24 hours easily.

An Optimized Heading De-Noising Method of the Polarization Compass for Improving Orientation Accuracy

In recent years, the polarization compass (PC) has been extensively applied in the field of autonomous navigation due to its strong autonomy and anti-interference characteristics. Nevertheless, the existing research shows that the PC with high extinction ratio polarization sensor still offers poor orientation accuracy since there is a great quantity of noise in the heading data output from the compass. Here, we present a novel and promising scheme to denoise heading data to improve deficiency in heading data denoising of existing research. The purpose of this study aims to solve the problem that the orientation accuracy of PC caused by noise needs to be improved. Concretely, the major points of this research include an effective separation strategy of noise and useful signal based on the optimized variational mode decomposition (OVMD) and an effective heading data denoising method based on an adaptive singular spectrum analysis (AD-SSA). OVMD based on the center frequency is employed to decompose the original noisy heading data into a finite number of band-limited data intrinsic mode functions (DIMFs) so that the best number of decomposed layers for the noising data can be obtained. Subsequently, the above decomposed DIMFs are divided into low-frequency signal components, mixed components, and high-frequency noise components exploiting the maximum similar eigenvalue of the autocorrelation matrix corresponding to each DIMF as a classification method. An AD-SSA uses the correlation coefficient to further suppress the noise in classified DIMFs. These approaches are combined effectively to improve the orientation accuracy of the PC significantly and very contribute to the navigation application of unmanned mobile platforms such as unmanned aerial vehicles (UAVs). Compared to existing prior arts, the effectiveness of the proposed heading denoising scheme for the PC is demonstrated through the results obtained from the heading data sets on two representative sunny and dust days.