Hook Position Research Articles

Modified Mandibular Lingual Arch for Orthodontic Traction of Impacted Mandibular Canine and Premolar: Case Reports

Impaction of the tooth can cause functional and esthetic problems, so early intervention is critical. This report describes two cases of orthodontic traction of impacted mandibular canine and mandibular premolar teeth using a modified mandibular lingual arch soldered with traction hooks rather than a conventional orthodontic appliance. By planning the position and shape of the traction hooks with consideration for the three-dimensional position and angulation of the impacted teeth, clinicians can apply the intended direction and magnitude of traction force. Furthermore, this appliance can be used for multiple impacted teeth in various locations within the mandibular arch by modifying the position and shape of the traction hooks.

Retraction Note: Study on optimization of vehicle exhaust system noise and hook position based on multi-source experimental data analysis

Retraction Note: Study on optimization of vehicle exhaust system noise and hook position based on multi-source experimental data analysis

Vision-Based Automated Recognition and 3D Localization Framework for Tower Cranes Using Far-Field Cameras.

Tower cranes can cover most of the area of a construction site, which brings significant safety risks, including potential collisions with other entities. To address these issues, it is necessary to obtain accurate and real-time information on the orientation and location of tower cranes and hooks. As a non-invasive sensing method, computer vision-based (CVB) technology is widely applied on construction sites for object detection and three-dimensional (3D) localization. However, most existing methods mainly address the localization on the construction ground plane or rely on specific viewpoints and positions. To address these issues, this study proposes a framework for the real-time recognition and localization of tower cranes and hooks using monocular far-field cameras. The framework consists of four steps: far-field camera autocalibration using feature matching and horizon-line detection, deep learning-based segmentation of tower cranes, geometric feature reconstruction of tower cranes, and 3D localization estimation. The pose estimation of tower cranes using monocular far-field cameras with arbitrary views is the main contribution of this paper. To evaluate the proposed framework, a series of comprehensive experiments were conducted on construction sites in different scenarios and compared with ground-truth data obtained by sensors. The experimental results show that the proposed framework achieves high precision in both crane jib orientation estimation and hook position estimation, thereby contributing to the development of safety management and productivity analysis.

RETRACTED ARTICLE: Study on optimization of vehicle exhaust system noise and hook position based on multi-source experimental data analysis

The exhaust system is one of the main sources of vehicle noise, and the hook position is one of the main factors affecting the exhaust system noise. Therefore, using the data optimization analysis method and optimizing the hook position parameters can improve the acoustic characteristics of the exhaust system and the vehicle ride comfort. In this paper, the method of multi-source test data analysis is proposed to obtain the A-weighted noise data of the exhaust system at different positions of the hook. Then, through preprocessing and regularization calculation and analysis of A-weighted noise characteristic data, the analysis results of multi-source test data with different location parameters are obtained. The noise contribution of multi-source test data analysis of hook C and hook A is 53.4% and 41.2%, while the noise contribution of multi-source test data analysis of hook B and hook D is negligible. Through the analysis and calculation of the multi-source test data of the hook position, the main influence data of the hook position on the noise is obtained, which provides a reference for further optimizing the vehicle exhaust noise characteristic parameters.

The Correspondence of G. H. Lewes and Charles Darwin

The Correspondence of G. H. Lewes and Charles Darwin

Parametric Optimization of Nozzle Turbine Vane Modal Characteristics by Means of Artificial System

Modal analysis is a fundamental assessment in the design phase of a nozzle guide vane in a low pressure turbine system. Evaluation is crucial for new concept design but also in case of design modification. The technical requirement is to ensure appropriate durability level (number of flight cycles) and the reliability of the system. An understanding of dynamic behavior is one of the key elements in the high cycle fatigue (HCF) evaluation. Finite element method (FEM) analyses are widely used in new product introduction phases to verify modal characteristics with respect to operating range and engine orders (forcing function, excitation). In the process used 2D representation of the nozzle guide vane approximated by axisymmetric and plane stress with thickness FEM plain elements. The optimization process used geometrical parameters (nozzle outer band and casing shell) and surrogate models to find optimal solutions from a frequency placement perspective. A sensitivity analysis and optimization process revealed casing shell thickness to be a major contribution in the modal response and weight. Excluding casing shell parameters led to a lower frequency shift with respect to the reference configuration. The presented optimization framework is very robust and time effective in completing the optimization task together with a sensitivity analysis for the defined design domain. An FEM model validation of the surrogate model showed consistency in the modal analysis results. A promising solution from the component weight standpoint is the optimization with hook position and leaning only. A future research recommendation is to study an extended parameter range to reduce weight impact for this set.

Fit and retention of complete denture bases: Part I – Conventional versus CAD-CAM methods: A clinical controlled crossover study

Statement of problemClinical evidence is sparse on whether dentures fabricated by computer-aided design and computer-aided manufacturing (CAD-CAM) methods afford superior fit and retention when compared with those fabricated conventionally. PurposeThe purpose of this clinical controlled crossover study was to evaluate the peak retention force and fit of CAD-CAM manufactured (3D printed and milled) maxillary complete denture bases and conventional heat-polymerized bases (control). Material and methodsTwenty participants with edentulous maxillary arches were recruited. Impressions were made with a border-molded custom tray, and the resulting definitive cast was scanned. The conventional base was manufactured on the definitive cast with a hook and a 45-degree platform with a central notch and 2 lateral notches. The scan of the definitive cast was used for the fabrication of a milled and a printed base. The platform and hook position on the conventional base were transferred digitally to the milled and printed bases. All bases were scanned. A traction dynamometer was orientated into the notches, and retention was evaluated in the post dam and tuberosity areas. Scans were imported into a comparison software program which matched scans to their corresponding reference and performed a 3-dimensional comparison. The Friedman and Wilcoxon tests were used to compare between groups (confidence interval: 95%, α=.05). ResultsNineteen participants with a mean ±standard deviation age of 64.1 ±14.7 years completed all clinical sessions. No significant difference in peak retention was measured between milled (MB1), printed (PB1), and conventional (CB) bases in the post dam (CB: 12.44 ±9.62 N, PB1: 16.08 ±15.28 N, MB1: 14.52 ±17.07 N) and right tuberosity area (CB: 8.99 ±7.82 N, PB1: 11.28 ±9.57 N, MB1: 11.99 ±12.10 N). In the left tuberosity area, peak retention was lower for CB (10.03 ±8.39 N) than PB1 (14.98 ±14.72 N) and MB1 (13.55 ±15.53 N; P=.05). Compared with the definitive cast, the fit of the conventional base (0.18 ±0.01 mm) was closer than the printed (0.21 ±0.03 mm) and milled bases (0.21 ±0.02 mm) (P<.001). ConclusionsThe CD bases manufactured by CAD-CAM techniques provided retention and fit similar to that of conventionally manufactured bases and can therefore be considered suitable techniques.

Relationship Between Subacromial Bone Erosion and Hook Position of Clavicular Plate in Distal Clavicle Fractures.

To evaluate the influence of posterior hook position on subacromial bone erosion during surgical treatment of distal clavicle fractures with locking compression plate clavicle hook plate (CHP). Single-center retrospective study. Level V trauma center (university hospital). Twenty-one patients (mean age, 45.8 years) treated with CHP were included. One, 3, 15, and 2 patients had Neer type I, IIa, IIb, and V fractures, respectively. Open reduction and internal fixation were performed with locking compression plate CHP. All implants were removed after a mean of 6.1 months postoperatively. Japanese Orthopaedic Association shoulder scores were used to assess recovery. Radiographically, the coracoclavicular distance was measured as the distance between the tip of the coracoid process and the undersurface of the clavicle. Three-dimensional computed tomography was performed to identify bone erosion at the hook tips after implant removal. The distance from the acromioclavicular joint center to the bone erosion was divided into 5 areas at 5-mm intervals, and the position and depth of bone erosion were measured in each area. The mean follow-up period was 17.4 months; mean ± SD Japanese Orthopaedic Association score was 75.9 ± 4.7 at the final follow-up, whereas the mean duration of bony union was 4.4 ± 1.0 (SD) months. Delayed bony union was observed in one patient, whereas a second surgery was required in another due to acromion cut-out. Radiography showed overreduction in 95% of cases. The correlation coefficient showed a difference between coracoclavicular distance and the position of bone erosion measured by CT (Rs = 0.32, P = 0.006). Erosion under the acromion surface was found in all patients. The depth of erosion correlated with the posterior hook position (Rs = 0.29, P = 0.023). Posterior hook tip placement increased the likelihood of bone erosion and complications due to overreduction. CHP should be set more anteriorly beneath the acromion to prevent complications. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Optimization of Loading Condition for Maxillary Molar Intrusion with Midpalatal Miniscrews by Using Finite Element Analysis

An anterior open bite is one of the most difficult malocclusions in orthodontic treatment. For such malocclusion, orthodontic miniscrew insertion into both buccal and palatal alveolar regions has been indicated for molar intrusion, but it involves a risk of tooth root injury. To solve the problem, a midpalatal miniscrew-attached extension arm (MMEA) is adopted. However, this method causes palatal tipping of the molar because intrusive loads were applied only from the palatal side. Currently, a transpalatal arch is added to avoi0d tipping movement, but it induces the patient’s discomfort. Hence, the objective of this study was to evaluate the loading conditions for maxillary molar intrusion without tipping movement, only by MMEA through finite element (FE) analysis. FE models of maxillary right first molar and surrounding tissues were created. Three hook positions of MMEA were set at 6.0 mm perpendicular intervals in the occluso-apical direction along the mucosal contour. An intrusive unit load was applied from the palatal side of the molar, and various counter loads were applied from the buccal side. An optimal counter load for molar intrusion without palatal tipping was observed in each hook position. In conclusion, an ideal maxillary molar intrusion can be achieved only by MMEA with an optimal counter load.

Biomechanical Analysis of Clavicle Hook Plates with a Range of Posterior Hook Offsets Implanted at Different Acromion Positions in the Acromioclavicular Joint: A Finite Element Analysis Study

The clavicle hook plate is commonly used in acromioclavicular injuries; however, the biomechanical effect of the posterior hook offset and hook position is unclear. This study applied a finite element analysis (FEA) to evaluate these parameters to improve the clinical strategy. Nine FEA models with 0-mm, 5-mm, and 10-mm posterior hook offsets implanted in the anterior, middle, and posterior acromion were established to evaluate the stress distribution and the reaction force on the acromion. The 5-mm and 10-mm posterior hook offsets at all acromion positions reduced the reaction force on the acromion but slightly increased the stress on the clavicle. The 0-mm offset increased the reaction force at all acromion positions and was relatively lower at the middle acromion. The clavicle hook plate with a posterior hook offset reduces the reaction force on the acromion, providing a flexibility of the hook position. These results provide surgeons with the biomechanical basis for the hook offset and position and engineers with the mechanical basis for the implant design.

Research on Position Recognition System of Gantry Hoisting Based on Machine Vision

During the process of steel casting, the task of worker is to identify the relative position of gantry hook and lifting lug of hot metal ladle so as to judge the appropriate time when gantry crane is to be lifted. Worker needs to stand near hot metal ladle, which does great damage to human’s body if exposed to such a bad environment. For this reason, the author has designed a machine vision system to displace artificial recognition. The machine vision system consists of the vision recognition algorithm based on AlexNet Convolution Neural Network (CNN) and the improved Canny edge detection algorithm. AlexNet CNN completes the preliminary recognition of the image and provides the samples that meet the recognition conditions to the improved Canny algorithm. The improved Canny algorithm completes the extraction of parameters such as the relative distance between the gantry hook and lifting lug and the tilt Angle of gantry hook. The sample images are extracted from two environments: model simulation and field simulation. Experimental data shows that the recognition algorithm based on AlexNet CNN can achieve 100% image recognition rate, which is higher than other traditional machine learning algorithms; the improved Canny edge detection algorithm can improve edge quality of extracting images in harsh environments.

Inferior vena cava filter tilting between placement and retrieval is associated with caval diameter and need for complex retrieval techniques

PurposeInferior vena cava (IVC) filter tilt may lead to apex embedment and need for advanced retrieval techniques. This study assesses factors associated with filter tilt change over time and need for complex retrieval procedures. Materials and methods252 consecutive patients underwent retrievable IVC filter placement and removal at a single academic institution over 58 months. 182 (72.2%) patients met inclusion criteria. IVC filters included 168 (92.3%) Gunther Tulip and 14 (7.7%) Option filters. The primary outcome was medial-to-lateral IVC filter tilt change between placement and retrieval. Secondary outcomes included advanced retrieval technique use and multiple retrieval attempts. Independent variables included demographics, IVC diameter, filter hook position relative to the renal veins, and dwell time. Associations were determined using student's t-tests, ANOVA, and linear and logistic regressions. ResultsMean IVC diameter at placement was 19.2 ± 3.3 mm. Mean filter tilts at placement and retrieval were 6.1 ± 4.9° and 5.2 ± 5.0°, respectively. Mean tilt change was 5.0 ± 5.0°. Larger IVC diameter was associated with greater filter tilt change (p = 0.0004). While IVC diameter did not independently predict retrieval difficulty, greater tilt change and prolonged dwell time were associated with increased advanced retrieval technique use (p = 0.01 and 0.002, respectively). Results were unchanged in a subgroup analysis of patients treated with Gunther Tulip filters. ConclusionLarger IVC diameter predicts increased filter tilt change, which in turn is associated with challenging retrievals. Attention to IVC diameter during filter placement may anticipate tilt-related complications.

Sigambra sundarbanensis sp. nov. (Annelida, Pilargidae) from the Indian sector of Sundarbans Estuarine System, with remarks on parapodial glands

A new pilargid species, Sigambra sundarbanensis sp. nov., is described from the rivers Matla and Thakuran, in the central Indian sector of the Sundarbans Estuarine System. This species is characterized by several characters such as the starting position of the notopodial hooks, the length of the median antenna and the variation in number of the neuropodial chaetae. These characters distinguish the new species from its congeners. Some parapodial glands have been found in individuals of this species. The new species closely resembles Sigambra parva (Day, 1963). Additionally, an updated key of genus Sigambra is provided, along with a table indicating their morphological variations and a global map showing their type localities.

Reproducibility and Concurrent Validity of Manual Palpation with Rehabilitative Ultrasound Imaging for Assessing Deep Abdominal Muscle Activity: Analysis with Preferential Ratios.

The abdominal drawing-in maneuver (ADIM) is a clinical tool used for identifying preferential activity of deep abdominal muscles. However, concurrent validity and reproducibility of palpation during the ADIM has not been formally investigated. The aims of this study were (1) to assess intra- and interrater reliability of manual palpation during the ADIM, and (2) to determine the concurrent validity of manual palpation during the ADIM by calculating preferential activation ratio cut-off as assessed with ultrasound imaging (RUSI). Thirty-two subjects (n = 16 patients with nonspecific low back pain and 16 comparable healthy individuals) performed the ADIM in a supine hook-lying position. Two experienced assessors evaluated the presence or absence of preferential contraction of the deep abdominal muscles by palpation during the ADIM on 2 different days. Intrarater (test-retest) and interrater reliability of palpation were calculated using Cohen’s kappa coefficients. Muscle thickness of the transverse abdominis (TrA), internal oblique (IO), and external oblique (EO) muscles at rest and during the ADIM were also measured. TrA-Contraction Ratio (TrA-CR), TrA-Preferential Activation Ratio (TrA-PAR), and Modified-TrA-PR (M-TrA-PAR) were calculated. The concurrent validity of manual palpation was determined using the correlation between manual palpation and imaging and by calculating ROC curve (operating characteristics curve), Youden index, and sensitivity and specificity. Intra- and interrater reliability of manual palpation during the ADIM was excellent (k: 0.82–1.00) and good to excellent (k: 0.71–1.00), respectively. Interrater reliability for muscle thickness ranged from good to excellent (ICC3,1 0.79–0.91). Manual palpation and TrA ratio showed low to moderate correlations (r: 0.36–0.60). When evaluating the diagnostic accuracy of manual palpation, the best predictive model (ROC value: 0.89; p < 0.001) for correct a preferential contraction of TrA was obtained when the M-TrA-PAR was ≥0.08 (sensitivity: 0.95–1.00; specificity: 0.62). Good to excellent intra- and interrater reliability of manual palpation was found during the ADIM in both patients and healthy groups. Manual palpation showed concurrent validity for identifying the preferential activity of the TrA muscle supporting its use in clinical practice.

Influence of the Hook Position on the Vertical Vibrations of an Automobile Exhaust System: Application of the Robust Optimization Design

A robust optimization design method is proposed to investigate the influence of the hook position on the vertical vibration (bending) of an automobile exhaust system. A block diagram for the robustness analysis of the exhaust system is initially constructed from the major affecting factors. Secondly, the second-order inertia force is set as the vibration excitation source of the exhaust system and the displacement of four hooks of the exhaust system is selected as the variable factor. Then tests are carried out to investigate the resulting vertical bending considering four influencing factors and three levels of analysis. Finally, a variance analysis of the vertical bending is performed. The present study provides a set of guidelines to control the key factors affecting the vibration of vehicle exhaust systems while proposing an effective method to reduce vehicle vibration and improve noise analysis.

The Relationship Between Hip And Thigh Muscle Strength After Acl-reconstruction

PURPOSE: Weakness post ACL reconstruction (ACLR) of hip and thigh muscles are evaluated to track rehabilitation progress and/or inform decisions about return to sports. Lower extremity muscle adaptations are common mechanisms by patients coping with muscle weakness. Relationships among hip and thigh strength measures after reconstruction in ACLR patients may help identify potential coping mechanisms and targets for therapeutic intervention. METHODS: Thirty-four patients with primary unilateral ACLR (21.09±6.70yr, 18M, 170.82±11.95cm, 76.82±21.36kg, 7.97±5.22 mo post ACLR) performed maximum isometric contractions for hip abduction (AB) and adduction (AD) in a supine hook-lying position with the hips flexed to 45-degrees and knee flexed to 90-degrees and knee extension (EX) and flexion (FL) while seated with the hip and knee flexed to 90-degrees; average peak torque was recorded and normalized to body mass. We used Pearson correlation coefficients to determine associations among hip and knee muscle strength. RESULTS: There were statistically significant positive relationships between all hip and thigh strength values of both limbs (Table 1). Correlations between knee EX and hip AB of the ACLR limb were between 0.640 and 0; the contralateral limb was between 0.583 and 0.769. Correlations between knee FL and hip AB of the ACLR limb were between 0.600 and 0.615; the contralateral limb was between 0.583 and 0.606. Correlations between knee EX and hip AD of the ACLR limb were between 0.579 and 0.726; the contralateral limb was between 0.574 and 0.754. Correlations between knee FL and hip AD of the ACLR limb were between 0.681 and 0.702; the contralateral limb was between 0.642 and 0.700. CONCLUSION: Statistically significant, moderate to strong, positive relationships among hip and thigh strength measures were found of both limbs about 7 months post ACLR. Relationships among hip and quadricep strength are all moderate to strong, appearing slightly weaker in the ACLR limb.

Trauma Mechanisms of Acute Knee injuries in Bouldering and Sport Climbing

BackgroundThere is limited insight into trauma mechanisms of knee injuries in bouldering and sport climbing for both non-competitive and competitive athletes.PurposeBased on a recent rapid increase of knee injuries caused by bouldering and sport climbing, we aimed to examine traumatic mechanisms of injury, demographics, distribution and severity of knee injuries in affected athletes.Study DesignCase series; Level of evidence, 4.MethodsWithin a four-year period, we performed a retrospective multi-center analysis of acute knee injuries in both competitive and non-competitive climbers. Traumatic mechanisms were inquired and severity levels, therapies and outcomes recorded using Visual Analog Scale (VAS), Tegner, Lysholm and a climbing-specific outcome score.ResultsA total number of 71 patients (35% competitive athletes and 65% non-competitive athletes) with 77 independent acute knee injuries were identified. Four different trauma mechanisms were thereby recorded: High step (20.8%), Drop knee (16.9%), Heel hook (40.3%) and (ground) Fall (22.1%). The leading structural damage was medial meniscal tear (29.3%), found significantly more often in non-competitive athletes. A specific climbing injury is iliotibial band strain during the heel hook position, causing 46.8 % of all injuries; most injuries resulted from indoor bouldering. Surgical procedures were predominantly necessary within the non-competitive group. One year after the injury, the average Tegner score was 5.6 ± 0.6 (3-6), Lysholm score was 97 ± 4.8 (74-100) and climbing specific outcome score was 4.8 ± 0.6 (2-5).Conclusion:Increased attention on the climber’s knee is required, especially due to the worldwide rise of indoor bouldering. Sport specific awareness- and training programs for both noncompetitive and competitive climbers to reduce acute knee injuries should be developed and sports medical supervision is mandatory.

Experimental and Numerical Investigation on Load-Bearing Performance of Aluminum Alloy Upright Column in Curtain Walls under Wind Pressure

In this paper, the wind resistance performance test and numerical simulation analysis of aluminum alloy columns with different structural measures in unit glass curtain walls are carried out. The two-layer experimental model were composed of 12 unit curtain walls, of which there are 2 beams at a distance of 1.2 m from the top and bottom in 9 unit curtain walls respectively, and there is only one beam at a distance of 1.2 m from the top in 3 unit curtain walls. The dimension of each unit curtain wall is 1.2 m × 4.0 m. The section shape of the experimental model is L-shaped. Firstly, the experimental investigation and analysis of the model with arrangement of one pair of hooks under positive and negative wind were carried out. Secondly, the experimental investigation and analysis of the model with no hooks under positive and negative wind were carried out. The out-of-plane deformation, in-plane deformation and the strain of the columns were collected and analyzed. Finally, finite element analysis model was established. The similarities and differences of the analysis results and the experimental results were analyzed. The results show that the beam has a small constraint on the columns whether the wind pressure is positive or negative when the number and position of hooks are reasonable. When the wind pressure is negative, the hook has little effect on the out-of-plane deformation and stability. Under the action of positive wind, the hooks can significantly reduce the in-plane deformation and restrain the lateral torsion deformation of the columns.

Mechanisms of Acute Knee Injuries in Bouldering and Rock Climbing Athletes

Background: There is limited insight into the mechanisms of knee injuries in rock climbing and bouldering in noncompetitive and competitive athletes. Purpose: To examine the traumatic mechanisms of injury, demographics, distribution, and severity of knee injuries in affected athletes. Study Design: Case series; Level of evidence, 4. Methods: During a 4-year period, we performed a retrospective multicenter analysis of acute knee injuries in competitive and noncompetitive climbing athletes. Traumatic mechanisms were inquired and severity levels, therapies, and outcomes recorded with visual analog scale, Tegner, Lysholm, and climbing-specific outcome scores. Results: Within the observation period, 71 patients (35% competitive athletes, 65% noncompetitive athletes) with 77 independent acute knee injuries were recorded. Four trauma mechanisms were identified: high step (20.8%), drop knee (16.9%), heel hook (40.3%), and (ground) fall (22.1%). The leading structural damage was a medial meniscal tear (28.6%), found significantly more often in the noncompetitive group. A specific climbing injury is iliotibial band strain during the heel hook position. Most injuries resulted from indoor bouldering (46.8%). Surgical procedures were predominantly necessary in noncompetitive climbers. One year after the injury, the Tegner score was 5.9 ± 0.8 (mean ± SD; range, 3-7); the Lysholm score was 97 ± 4.8 (range, 74-100); and the climbing-specific outcome score was 4.8 ± 0.6 (range, 2-5). Conclusion: Increased attention should be placed on the climber’s knee, especially given the worldwide rise of indoor bouldering. Sport-specific awareness and training programs for noncompetitive and competitive climbing athletes to reduce knee injuries should be developed, and sports medical supervision is mandatory.

The real-time vision measurement of multi-information of the bridge crane’s workspace and its application

The measurement of the workspace information of the bridge crane is the premise of its intelligent control and safety monitoring. Some existing vision systems can only obtain very limited information, like swing angle of the payload. In this paper, a monocular vision measurement method is proposed to acquire multi-information of the payload off-centered angle, the payload rotation angle and the obstacle height. A hierarchical calibration method is designed to divide the large lifting height of the crane into multi-layers. At each layer, four markers are fixed on a plate symmetrically to obtain the center position of hook via the Blob analysis and ellipse fitting algorithm. After calibration, two fitting equations of the payload lifting height and the pixel coordinate of vertical lifting center are established corresponding to the pixel distance between two markers and the height of each layer. On the base of the two fitting equations, the measurement models of the payload off-centered angle, the payload rotation angle and the obstacle height are established combining with the geometric relations in the crane’s workspace, respectively. Finally, a crane prototype is established to validate the effectiveness of the vision measurement models. Moreover, the strategies of auto-centering control and automatic obstacle avoidance are designed utilizing the vision measurement system. The corresponding experiments were carried out and achieved a good performance. The research results of this paper have practical significance to intelligent control and safety monitoring of the crane in future.