Auxiliary Frame Research Articles

Lightweight tomato ripeness detection algorithm based on the improved RT-DETR.

Tomatoes, widely cherished for their high nutritional value, necessitate precise ripeness identification and selective harvesting of mature fruits to significantly enhance the efficiency and economic benefits of tomato harvesting management. Previous studies on intelligent harvesting often focused solely on identifying tomatoes as the target, lacking fine-grained detection of tomato ripeness. This deficiency leads to the inadvertent harvesting of immature and rotten fruits, resulting in economic losses. Moreover, in natural settings, uneven illumination, occlusion by leaves, and fruit overlap hinder the precise assessment of tomato ripeness by robotic systems. Simultaneously, the demand for high accuracy and rapid response in tomato ripeness detection is compounded by the need for making the model lightweight to mitigate hardware costs. This study proposes a lightweight model named PDSI-RTDETR to address these challenges. Initially, the PConv_Block module, integrating partial convolution with residual blocks, replaces the Basic_Block structure in the legacy backbone to alleviate computing load and enhance feature extraction efficiency. Subsequently, a deformable attention module is amalgamated with intra-scale feature interaction structure, bolstering the capability to extract detailed features for fine-grained classification. Additionally, the proposed slimneck-SSFF feature fusion structure, merging the Scale Sequence Feature Fusion framework with a slim-neck design utilizing GSConv and VoVGSCSP modules, aims to reduce volume of computation and inference latency. Lastly, by amalgamating Inner-IoU with EIoU to formulate Inner-EIoU, replacing the original GIoU to expedite convergence while utilizing auxiliary frames enhances small object detection capabilities. Comprehensive assessments validate that the PDSI-RTDETR model achieves an average precision mAP50 of 86.8%, marking a 3.9% enhancement over the original RT-DETR model, and a 38.7% increase in FPS. Furthermore, the GFLOPs of PDSI-RTDETR have been diminished by 17.6%. Surpassing the baseline RT-DETR and other prevalent methods regarding precision and speed, it unveils its considerable potential for detecting tomato ripeness. When applied to intelligent harvesting robots in the future, this approach can improve the quality of tomato harvesting by reducing the collection of immature and spoiled fruits.

Deep Video Super-Resolution Using Hybrid Imaging System

High-resolution high-frame-rate videos can record motion scenes detailedly and smoothly, but usually only professional cameras have enough transmission bandwidth to meet the video capture requirement. The conventional solutions use video processing methods such as video super-resolution (VSR) and video frame interpolation (VFI), but their results suffer from unreal spatial-temporal details in complex dynamic cases. To address this problem, we reconstruct a more real high-resolution high-frame-rate video using a hybrid video input, including a low-resolution high-frame-rate video (main video) and a high-resolution low-frame-rate video (auxiliary video). We propose a deep learning model named HIS-VSR, which consists of three parts: super-resolution of the main video, detail feature extraction of the auxiliary video and hybrid video information aggregation. Among them, the first part processes the main video to generate preliminary high-resolution frames; the second part warps the auxiliary frames for alignment and extracts their high-resolution detail features; the last part uses a weighted aggregation method to fuse the results of the first and second part. We train our model on synthetic datasets and demonstrate its excellent performance of reconstructing dynamic scenes by comparing it with Deep-SloMo on synthetic and real videos.

Coupling numerical and experimental methods to characterise the mechanical behaviour of the Mona Lisa: a method to enhance the conservation of panel paintings

A numerical FEM (Finite Element Method) model was implemented to represent the mechanical state of the wooden panel of the Mona Lisa, as it is conserved in its exhibition case, and constrained in its auxiliary frame. The model is based on the integration of advanced numerical analysis and various experimental examinations carried out non-invasively on the artwork by the authors during over 15 years. This includes visual, microscopic and X-ray observations together with mechanical measurements and monitoring of panel deformations and constraining external forces. In addition to the development of non-invasive techniques to characterise the mechanical properties of the panel, the FEM model reliably evaluated the strains and stresses generated in the panel by the various actions it experiences. The paper consists of the following parts: (i) a short summary of the experimental measurements and other observations, (ii) a detailed description of the FEM numerical model, of the hypotheses it is based on, and of its advantages and limits, (iii) the main results obtained by running the model. This includes the identification of local strains and stresses, the location of most critical areas, an evaluation of the risk that the existing ancient crack may propagate, and an evaluation of safe ranges for the forces acting on the wooden panel, (iv) the validation criteria for such results, and (v) a discussion about the significance of the mechanical model.

Unilateral External Fixator Combined with Lateral Auxiliary Frame for Ultimate Treatment of Tibia and Fibula Shaft Fractures with Poor Soft Tissue Conditions.

Background For severe soft tissue damage or open fracture, unilateral external fixation is one of the treatment choices. In the current study, a unilateral external fixator combined with a lateral auxiliary frame was used to treat tibia and fibula shaft fractures with poor soft tissue conditions to verify its feasibility for the ultimate treatment. Methods We retrospectively analyzed the patients with tibia and fibula shaft fractures who underwent unilateral external fixator combined with lateral auxiliary frame between December 2018 and October 2020. The clinical outcomes were recorded. Results 31 patients with tibia and fibula shaft fractures who received unilateral external fixator combined with lateral auxiliary frame were included in the current study. Among them, 23 cases had closed fractures with poor soft tissue and 8 cases had Gastilo type I open fractures. The average duration of hospital stay was 7.3 ± 2.3 days. The causes of injury were traffic accidents in 15 cases (48.4%), fall from height in 7 cases (22.6%), crush injury in 5 cases (16.1%), and other causes in 4 cases (12.9%). During follow-up, the clinical healing time was 3.0 ± 0.85 months. Additionally, the infection rate of pin-tract and reoperation rate was 12.9% and 3.2%. Fortunately, all patients achieved fracture healing and recovered well without joint dysfunction and obvious claudication. The Johner-Wruh scores showed that 27 cases (87.1%) were “excellent” and 4 cases (12.9%) were “good.” Conclusions The unilateral external fixator combined with lateral auxiliary frame is an effective option for ultimate treatment of the tibia and fibula shaft fractures with poor soft tissue conditions.

An improved minimal error model for the robotic kinematic calibration based on the POE formula

SummaryThe conventional product of exponentials $\left(\rm POE\right)$ -based methods dissatisfy the parametric minimality for the kinematic calibration of serial robots due to overlooking the magnitude and pitch constraints. Thus, the minimal kinematic model is presented to solve this problem, which can be developed further. This paper puts forward an improved algorithm for the minimal parameter calibration. An actual kinematic model with the minimal parameters $\left(\rm MP\right)$ is constructed according to the geometric properties of actual joint twists in the auxiliary frames established on the basis of the nominal joint axes. Then, the initial pose error is defined in the tool coordinate frame, which is expressed as the exponential map of the twist, and all twist descriptions are unified, so as to give a unified kinematic model in mathematics. By differentiating the kinematic model, a minimal error model is derived in explicit form. Subsequently, we propose a novel parameter identification method, which identifies the orientation error and position error parameters separately by the iterative least-squares method and updates the MP uniformly. Finally, the simulations and experiments on the different serial robots are conducted to verify the correctness and effectiveness of the proposed algorithm. The simulation results show our calibration algorithm outperforms the existing ones in the accuracy aspect, and the experiment result shows that the absolute pose accuracy of the UR5 industrial robot is upgraded about 9 times under a statistics sense after the calibration.

Hydraulic System Design of Temporary Support for Fast Excavation of Top Coal

Aiming at the problems of long time-consuming auxiliary operation, low excavation efficiency, high labor intensity and poor production safety in mechanized excavation construction of coal roadway, a temporary support for rapid excavation of top coal in thick coal seam is developed. The support is composed of inner frame assembly, outer frame assembly, inner and outer outrigger oil cylinders, walking oil cylinder, deviation rectification oil cylinder, auxiliary frame, hydraulic pipeline and hydraulic system. Through the design of the hydraulic system of the temporary support for the fast excavation of top coal in thick coal seam, the working pressure of the hydraulic system is determined, the composition and working principle of the hydraulic control system are analyzed and designed, and the hydraulic cylinder of inner frame outrigger, the hydraulic cylinder of outer frame outrigger, the hydraulic cylinder of auxiliary frame, the horizontal hydraulic cylinder and the adjustable spring hydraulic cylinder of the temporary support for the fast excavation of top coal in thick coal seam are designed and verified. The temporary support for fast excavation of top coal in thick coal seam can timely support the new exposed roof cut by roadheader, protect the safety of personnel and equipment in the working space, shorten the working time of support, improve the working efficiency of excavation support, reduce the labor intensity of workers, improve the production safety, accelerate the excavation speed of heading face, and improve the economic and social benefits of enterprises.

A modified velocity updating algorithm for a strapdown INS

Velocity updating typically involves integration of the transformed specific force and gravity Coriolis velocity increments. If the angular rate and specific force vectors maintain fixed directions relative to a frame, updating the velocity in that frame will be straightforward. In practice, the coning angular rate and sculling specific force vectors cause a calculation error in velocity updating on the navigation frame. Thus, the development of sculling compensation algorithms for the reduction of the sculling error is necessary. In this study, a new method for the propagation of vehicle velocity is proposed. This method utilizes an auxiliary frame that slews along with the angular rate and specific force vectors, which remain fixed in the auxiliary frame. This transforms and integrates the specific force vector in this auxiliary frame such that it is error-free. Additionally, the updated velocity can be obtained by translating the above results to the navigation frame, thereby avoiding the need for sculling correction. The validity of this proposed method under the influence of a typical slewing motion was established experimentally, suggesting that it provides an efficient and accurate velocity propagation method that can be employed in aerospace applications.

Velocity updating based on two auxiliary frames

The conventional velocity updating algorithms are sufficient for the low and medium-accuracy strapdown INS. However, the accuracy of conventional algorithms is not sufficient for a high-accuracy strapdown INS and the high-dynamic environment. To solve this issue, a new velocity updating algorithm is proposed in this paper. It employs two auxiliary frames to reduce the rate of change in direction of the specific force and angular rate vectors. The first slewing frame slews at a constant rate about a fixed axis in the vehicle frame and the second slewing frame slews at a constant rate about a fixed axis in the first slewing frame. With the proper choice of slew rates, the angular rate and specific force vectors of the second slewing frame changes direction more slowly than that of the vehicle frame. Integrating of the transformed specific force vector in the second slewing frame and then translating it to the navigation frame could determine the updated velocity. The velocity updating algorithm presented in this paper does not involve sculling correction. Simulation and trial results demonstrated that this algorithm has a higher accuracy than the conventional algorithms. This algorithm plays an important role in the high-dynamic environment and a high-accuracy strapdown INS.

Deep Slow Motion Video Reconstruction With Hybrid Imaging System.

Slow motion videos are becoming increasingly popular, but capturing high-resolution videos at extremely high frame rates requires professional high-speed cameras. To mitigate this problem, current techniques increase the frame rate of standard videos through frame interpolation by assuming linear object motion which is not valid in challenging cases. In this paper, we address this problem using two video streams as input; an auxiliary video with high frame rate and low spatial resolution, providing temporal information, in addition to the standard main video with low frame rate and high spatial resolution. We propose a two-stage deep learning system consisting of alignment and appearance estimation that reconstructs high resolution slow motion video from the hybrid video input. For alignment, we propose to compute flows between the missing frame and two existing frames of the main video by utilizing the content of the auxiliary video frames. For appearance estimation, we propose to combine the warped and auxiliary frames using a context and occlusion aware network. We train our model on synthetically generated hybrid videos and show high-quality results on a variety of test scenes. To demonstrate practicality, we show the performance of our system on two real dual camera setups with small baseline.

Structural and energy storage retrofit of an electric bus for high-power flash recharge

The activity here presented describes the retrofit performed on a small-size electric urban bus, which has been transformed in a laboratory vehicle for flash charge functionality using energy transfer between supercapacitors. The existing motor and driveline has been maintained, while the energy storage, originally based on lead batteries, has been modified reducing battery capacity and installing high voltage supercapacitors; such hybrid energy storage system is able to accept high recharge power (approximately about 150kW-peak in the used configuration), while smoothing power load on battery during traction. The system is therefore also able to extend the life of aged batteries. The so-called flash charge occurs through a pantograph connection to the infrastructure, typically in case of bus stops, during ascent and descent of passengers. The structure of the vehicle used for the transformation, which is still widely used worldwide, is constituted by as a glass fiber bodywork installed on a steel frame; since the body was not designed for the support of a significant mass as the one of the pantograph, it has been necessary to install an additional frame anchored to the main vehicle frame; such auxiliary frame has been designed also to substitute the internal fittings of the vehicle, in order to be used as stanchions for the standing passengers. In parallel, the battery compartment has been redesigned in order to install the supercapacitors and the new power converters needed. The contents of the article include the description of the mechanical components installed for the retrofit, the definition of the main power management strategy for the new powertrain and the results of preliminary testing activities.

Trefftz polygonal finite element for linear elasticity: convergence, accuracy, and properties

In this paper, the accuracy and the convergence properties of Trefftz finite element method over arbitrary polygons are studied. Within this approach, the unknown displacement field within the polygon is represented by the homogeneous solution to the governing differential equations, also called as the T-complete set. While on the boundary of the polygon, a conforming displacement field is independently defined to enforce the continuity of the field variables across the element boundary. An optimal number of T-complete functions are chosen based on the number of nodes of the polygon and the degrees of freedom per node. The stiffness matrix is computed by the hybrid formulation with auxiliary displacement frame. Results from the numerical studies presented for a few benchmark problems in the context of linear elasticity show that the proposed method yields highly accurate results with optimal convergence rates.

Lightweight Design on Auxiliary Frame of Mixer Truck

Lightweight Design on Auxiliary Frame of Mixer Truck

A Virtual Reality Environment for 5-DOF Robot Manipulator based on XNA Framework

ABSTRACT This work presents a complete solution for the Forward and Inverse Kinematics for a 5DOF robot manipulator and use XNA game studio as a simulator. The work include mathematical modeling of the robot Kinematics which it used in a 3D virtual environment. This text show that it can be use XNA GS as an excellent tool to simulate robots behavior. Keywords inverse kinematics, Lab volt 5150, XNA, Simulation, Virtual reality. 1. INTRODUCTION Many researches dealt with the analysis for inverse Kinematics of a 5-DOF manipulator considered that it should deal with the problem as an analysis for 6-DOF manipulator losing one degree of freedom [1], [2] and deficiency of degrees of freedom makes the control of manipulators with less than 6-DOF very difficult when following a given trajectory[3]. Some algebraic solutions for inverse Kinematics of a 5-DOF manipulator assume that summation of joint angles 2,3 and 4 (θ_234) is a constant value, so it didn't solve all the joint angles. [4] introduced analysis for Forward Kinematics of 5-Dof and didn't deal with inverse Kinematics of the robot. C. S. G Lee, M. Ziegler [5] solve the problem of choosing a solution among multi solutions generated as a result of left and above arm, right and above arm, left and below arm, right and below arm and wrist flip configurations by assuming an indicators, this way need that joint angles already known. In this paper, a 5-DOF manipulator which is Lab-Volt 5150 series was modeled and analyzed without assuming any auxiliary frame. All the driven forward and inverse Kinematics shows a great deal of accuracy theoretically and experimentally, also the problem of multi solutions was solved by suggesting an algorithm that choose the best configuration for a point in space represented by a position vector and orientation matrix. A virtual reality environment developed to simulate the movements of the robot arm using C#.Net language XNA framework. Virtual reality is a system which allows one or more users to move and react in a computer generated environment. The basic VR systems allow the user to visual information using computer screens [6]. Section 2 shows the modeling of the robot manipulator and D-H parameters associated with the model. Section 3.1 introduces the analysis of the forward Kinematics and use Lab-Volt 5150 as a case study. Section 3.2 introduced the problem of the singularity and it was proved that there are no singularity. Section 4 offer the inverse Kinematics analysis and set all the governing equations for all the joints angles. Section 5 give the theoretical and experimental results done. finally section 6 give the conclusions.

Hybrid Fundamental Solution Based Finite Element Method: Theory and Applications

An overview on the development of hybrid fundamental solution based finite element method (HFS-FEM) and its application in engineering problems is presented in this paper. The framework and formulations of HFS-FEM for potential problem, plane elasticity, three-dimensional elasticity, thermoelasticity, anisotropic elasticity, and plane piezoelectricity are presented. In this method, two independent assumed fields (intraelement filed and auxiliary frame field) are employed. The formulations for all cases are derived from the modified variational functionals and the fundamental solutions to a given problem. Generation of elemental stiffness equations from the modified variational principle is also described. Typical numerical examples are given to demonstrate the validity and performance of the HFS-FEM. Finally, a brief summary of the approach is provided and future trends in this field are identified.

Based on the Structural Mechanics of Dump Truck Chassis Frame of Design Improvement

EQ3090 dump truck in the basis of EQ1090 modification and become, the chassis choose EQ1090 chassis. The modification of the main frame, including the main frame of the drilling and welding, the main frame of extension design, main frame of reinforcing plate design. Auxiliary frame modified, include the auxiliary frame of the cross section shape and size, reinforcing plate decorate, deputy frame front shape and installation location, rail and beam connection design, auxiliary frame and the main frame connection design, and finally, the auxiliary frame in intensity. The refit vehicle meet the using performance and achieve the anticipated goal.

Optimization Design on Triangle Plate of Auxiliary Frame of Mixer Truck

In order to solve the question of crack of the auxiliary frame of mixer truck, especially with the life of the triangle welding position is low, the triangle support of auxiliary frame optimization design is put forward Firstly, three dimensional structure model of auxiliary frame is established by Pro/E and the model is imported into HyperMesh software for meshing. The solver RADIOSS is used to calculate the maximum stress and the positions at the different full load conditions. Including the static, left front wheel lifted up by 210 mm, the right rear wheels (double) lifted up by 210 mm and the left front and right rear wheels lifted simultaneously up by 210 mm. Then the experimental vehicle test is performed. The test results and simulation results are compared and show a good consistency and the accuracy of the finite element model is validated. Then the three optimization design schemes of the triangle are put forward and the maximum stress of the optimal auxiliary frame are calculated in contrast with the original stress. The scheme 2 is found to be the most optimal, which provides an effective method for solving the fatigue of the auxiliary frame.

Modal Distribution and Optimization for Auxiliary Frame Based on Hypermesh

Auxiliary frame, as a skeleton of a front and rear axle, in order to improve its performance, this paper takes a SUV auxiliary frame as an example. Make the finite element modeling and do Strength and modal analysis through Hypermesh. Show the previous six order modal frequency, take the idle vibration frequency of engine, the second harmonic vibration frequency and the target vehicle auxiliary frame mode for the target to do modal optimizations.Finally make each order modal of the auxiliary frame satisfy the target, reduce the risk of vibration noise, the incoming road vibrations and enhance comfort of the vehicle.

A Novel Line Scan Camera Calibration Technique With an Auxiliary Frame Camera

A practical line scan camera calibration technique for close-range photogrammetric applications is proposed. It is implemented by rigidly coupling the line scan camera to an auxiliary frame camera whose intrinsic parameters have been obtained in advance. Then, the calibration is divided into two independent stages. First, images of a 2-D dynamic pattern are acquired by the two cameras from several different views. Based on these images and line scan camera model, intrinsic parameters of the line scan camera and rigid transform parameters between the two coupled cameras are calibrated. This work can be accomplished previously in workroom. Secondly, in photogrammetry, extrinsic parameters of the line scan camera are determined indirectly via space resection of the auxiliary frame camera and the obtained rigid transform parameters of the two cameras. Experiments show that our calibration can provide robust and accurate results.

Fundamental Solution Based Finite Element Method

assumed fields (intra-element filed and auxiliary frame field) are employed and the domain integrals in the variational functional can be directly converted to boundary integrals without any appreciable increase in computational effort as in HT-FEM.the assumed intraelement field was constructed by the linear combination of fundamental solutions at points outside the elemental domain under consideration, The independent frame field was introduced to guarantee the interelement continuity and the stationary condition of the new variational functional is used to obtain the final stiffness equations.

An Improved Difference Method Based on Three Asymmetric Frames and its Applications in the Vehicle Detection

Original difference method based on three sequential frames is a common method in the moving objective detection. After the introduction of the original method, the formation cause of the internal cavity in vehicle region was analyzed. Then, an improved difference method based on three asymmetric frames, which were abstracted according to the judgment rule of optimal frame interval, has been proposed in this paper. The area of the moving vehicle region is assumed as the criterion to calculate the best frame interval. In the improved method, the best benchmark frame and the best auxiliary frame were firstly abstracted out and used to subtract the current frame separately. Subsequently, the two difference images were transformed to binary images separately. Lastly, the final moving vehicles were detected in the current frame after logical "and" operation was carried out between the two binary images. The experimental results showed that the improve difference method based on three asymmetric frames can effectively reduce the internal cavities in the vehicle region, comparing with the original one.