404 results about "Rigid body" patented technology

The invention belongs to the technical field of hypersonic flight vehicle control, and relates to a rigid-elastic coupling-oriented active and passive integrated control method for a hypersonic flight vehicle. The invention aims to realize stable tracking control of the elastic hypersonic flight vehicle. The method comprises the following steps: constructing a longitudinal dynamic model of the elastic hypersonic aircraft; self-adaptive identification of the elastic vibration frequency is realized through a cascaded self-adaptive filter; an elastic modal filtering estimation method is designed, and high-precision and low-cost elastic modal state quantity is provided for subsequent active feedback controller design; and then rigid-elastic coupling model decomposition is carried out, the control performance is ensured by using active disturbance rejection passive control for a rigid body subsystem, an RBF neural network is introduced for an elastic subsystem, an elastic mode is actively inhibited by using sliding mode control, and stable tracking of a reference instruction is realized. The method is an active and passive integrated control method for the hypersonic flight vehicle oriented to rigid-elastic coupling, and the application prospect is wide.

The invention relates to the technical field of computer vision and industrial automation, and particularly discloses a MARK point high-precision PCB positioning and mechanical mapping method based on multi-coordinate system fusion, which is composed of PCB positioning and mechanical mapping in a template stage and PCB positioning and mechanical mapping in a production stage. Wherein the PCB positioning and mechanical mapping in the template stage comprises the steps of coordinate system establishment and image coordinate distortion correction; the PCB positioning and mechanical mapping in the production stage comprises Mark point real-time detection and offset calculation, real-time attitude solution and dynamic matrix calculation, and mechanical coordinate calculation of any PCB point. According to the method, a three-coordinate system collaborative modeling mechanism of an image coordinate system, a PCB coordinate system and a mechanical coordinate system is introduced, so that board attitude change and equipment fixing errors are separated, and the system robustness and the mapping precision are greatly improved; rigid body affine transformation is constructed by adopting double Mark points, the rotation angle, the proportion and the translation amount are solved in real time through two-point geometric constraint, and self-adaptive compensation of the posture change of the PCB is achieved.

The invention relates to a basketball player motion capture analysis method and system based on an industrial camera. The method comprises the following steps: based on a preset three-dimensional human body model, obtaining a three-dimensional human body surface grid sequence and internal skeleton joint kinematics data by combining a pixel-level mask of each multi-view image frame set; detecting a body contact event and a continuous time period based on the Euclidean distance of the three-dimensional human body surface grid sequence; based on the internal skeleton joint kinematics data, calculating a multi-dimensional kinematics feature time sequence; constructing a dynamic causal hypothesis based on the body contact event, checking the dynamic causal hypothesis based on a preset differentiable forward dynamic multi-rigid-body human body model and a multi-dimensional kinematics characteristic time sequence to obtain a loss function value, and judging the hypothesis with the smaller loss function value as a real dynamic causal relationship. And the identity identification information is combined to obtain the identity of the active force generation party and the identity of the passive force bearing party. By adopting the method, a real force exerting main body and a real force bearing main body in confrontation can be accurately identified.

The invention discloses a welding robot welding seam positioning method for shipyard part machining. The problems that an existing method is poor in deformation adaptation, weak in interference resistance and insufficient in positioning precision for shipyard large-size parts are solved. The method comprises the four steps that 1, a to-be-welded part is pre-fixed through a shipyard special tool, and a laser contourgraph, a millimeter wave radar and an industrial camera are combined to collect multi-source features; 2, obtaining a final welding seam positioning coordinate through multi-source feature layered extraction (a global reference feature layer builds a coordinate network, and a local welding seam feature layer improves a groove / gap parameter), global-local correlation matching (a rigid body transforms a mapping coordinate and calculates a deformation deviation) and dynamic deviation compensation (cubic spline interpolation fits a deformation curve and generates a three-dimensional compensation amount); 3, a positioning coordinate calibration robot TCP is imported, and a path is generated according to the welding seam type; and 4, verifying the precision in a no-load manner, and recalculating the compensation amount if the deviation exceeds 0.1 mm. The method is high in positioning precision, strong in interference resistance and suitable for complex working conditions of shipyards.

The invention discloses a shaft system alignment key process identification and optimization method based on an error flow model, and the method comprises the steps: constructing an error source set in a shaft system assembly process, and building a related space coordinate system based on an assembly topological relation; establishing a nominal pose transfer equation based on an infinitesimal rigid body coordinate transformation principle; constructing a joint surface contact error vector by combining the diameter of the flange on the basis of a flange opening value and a dislocation value measured on site; performing first-order linearization processing on the nominal pose transfer equation based on the joint surface contact error vector, and obtaining a sensitivity matrix; constructing a state equation for describing error accumulation according to the sensitivity matrix and the error source set; a sensitivity coefficient is constructed based on a state equation and is compared with a judgment threshold, key control characteristics are identified, accurate errors can be predicted by quantifying a transmission mechanism of each error source, and key procedures are accurately identified in combination with the sensitivity coefficient, so that a reasonable strategy is adopted for optimization, and the product quality is ensured to be qualified.

The invention provides a three-dimensional water elasticity response calculation method based on boundary element-explicit finite element coupling, and belongs to the technical field of water elasticity response calculation based on computer data processing. The wave evolution of a fluid domain is solved by adopting a boundary element method, and the dynamic response of the elastic plate is solved by adopting an explicit finite element method. Inspired by an implicit boundary condition method of a wave-rigid body coupling effect, an explicit dynamic control equation of a structural domain elastic plate is substituted into a boundary condition met by an object plane acceleration potential of a fluid domain elastic plate, and an additional relation between an elastic plate surface fluid velocity potential time derivative and a normal derivative of the elastic plate surface fluid velocity potential time derivative is established; the implicit boundary condition is satisfied by the surface of the elastic plate. The deduced implicit boundary condition and the satisfied Laplacian equation are combined, and the value of the surface of the elastic plate can be accurately obtained. According to the three-dimensional time domain numerical method for wave-elastic plate coupling provided by the invention, stable and accurate calculation of wave load and structural response can be realized.

The invention discloses an autonomous underwater vehicle hydrodynamic coefficient solving method based on multi-degree-of-freedom coupling driving, and provides a multi-degree-of-freedom dynamic coupling driving joint simulation strategy aiming at the limitations of low efficiency, step-by-step calculation error accumulation and the like of a traditional hydrodynamic coefficient calculation method. Through deep fusion of a system identification theory and a six-degree-of-freedom rigid body motion equation, a full-degree-of-freedom coupling simulation platform based on dynamic grid self-adaption is developed, transverse fluid power interference under plane constraint motion is decoupled, and synchronous iterative solution of six-degree-of-freedom hydrodynamic parameters of surging, swaying, heaving, pitching, rolling and yawing is achieved. According to the method, six-degree-of-freedom coupling motion numerical simulation is carried out by taking an independently researched and developed cheongfish series AUV (Autonomous Underwater Vehicle) as an example, and all hydrodynamic coefficients can be solved only through one-time example calculation. According to the method, the hydrodynamic coefficient of the autonomous underwater vehicle can be rapidly obtained, and the purpose of accurately controlling the autonomous underwater vehicle is achieved.

The invention relates to the field of precision manufacturing of aero-engine blades, and particularly discloses an aero-engine blade grinding and polishing removal amount control method which comprises the steps that an industrial robot carries 3D visual equipment to conduct multi-angle scanning on a blade pasted with mark points, the number of public mark points between adjacent scanning poses is forcibly restrained to be larger than or equal to 3, and the number of the mark points is smaller than or equal to 3; a rigid body transformation matrix is solved based on space coordinate transformation, and high-precision point cloud automatic splicing is achieved; blade point clouds before and after grinding and polishing are reconstructed through Delaunay triangulation with consistent parameters, and a triangular mesh continuous curved surface is generated; calculating the minimum space distance from each vertex of the target curved surface to the source curved surface as a removal amount error epsilon, and positioning an out-of-tolerance region based on epsilon distribution; and generating a compensatory processing track by adopting an equal residual height method. The problem of point cloud registration caused by rare geometric features of the blade is solved, machining decision is driven through curved surface space errors, closed-loop accurate control over the removal amount is achieved, and the consistency of the grinding and polishing quality of the blade is improved.

The utility model discloses a torsion bar elastic restraint spherical steel support which comprises a longitudinal spherical steel support, the longitudinal spherical steel support comprises a fixed support bottom plate located at the bottom, a support bottom basin is arranged on the support bottom plate in a sliding mode, a torsion bar assembly for restraining and limiting is arranged on the support bottom plate, and the longitudinal spherical steel support comprises a longitudinal spherical steel support body. The torsion bar assemblies are arranged on the two opposite side faces of the support bottom basin. Horizontal movement of the pin shaft end of the torsion arm is restrained through the side plate slide way, rigid rotation of the torsion arm is achieved when the support moves, and the torsion arm rotates to drive the torsion rod spring to twist; a connecting rod assembly is removed, so that the structure is more compact; and the direction of external force is parallel to the axis of the fixing bolt, so that the stress of the bolt is optimized, and the bridge support is more suitable for the application scene of the bridge support.

The invention relates to the technical field of mechanical dynamics analysis and mechanism simulation, and discloses a guide rail impact and dynamic analysis method for a three-degree-of-freedom flat-bottom push rod cam mechanism, which comprises the following steps of: establishing a global coordinate system and a local coordinate system, and defining a push rod as a rigid body with three degrees of freedom of transverse, longitudinal and rotation; the effective input displacement of the cam is corrected according to the rotation angle, and the normal contact force, the friction force and the total cam contact torque are calculated; meanwhile, collision between four corners of the push rod and the guide rail is monitored, and guide rail impact force and guide rail impact total torque are calculated. And constructing a coupling dynamics differential equation set by integrating the force and the torque, and solving a motion state by using numerical integration. And further identifying the dynamic behavior of the system by using a Poincare section and a quintuple impact mode code. Simulation of inclination, overturning and multi-point impact of the push rod is achieved, the period, bifurcation and chaotic motion states of the system can be effectively recognized, and theoretical support is provided for mechanism optimization design.

The invention relates to the field of intelligent equipment control and industrial automation, in particular to an intelligent equipment butt-assembling cooperative control system with multi-axis linkage compensation. The data acquisition module is used for acquiring current, force / torque, temperature, position and speed data under a unified time reference; the benchmark reconstruction module is used for generating an ideal position benchmark and an ideal force / torque benchmark on the basis of an ideal rigid body model under a preset reference coordinate system; the parameter injection module is used for injecting thermoelastic deformation, rigidity attenuation and hysteresis friction parameters to generate a theoretical simulation state; constructing a double-track difference module of a real residual error and a theoretical residual error; the coupling judgment module is used for carrying out time sequence similarity verification and generating a state judgment result; the feedback control module is used for outputting a multi-axis linkage compensation instruction or a compliant return instruction; according to the invention, inherent drift and real assembly interference of equipment can be distinguished, and stable compensation and safe concession control are realized.

The invention relates to the technical field of aeroelastic analysis of aero-engines, in particular to a boosting-energy complementing gliding aircraft thermal / aeroelastic coupling modeling and analysis method considering rigid-elastic coupling. A frame for simultaneously solving rigid body motion and elastic vibration is established, the amplitude and direction disturbance characteristics of thrust pulsation and the rigidity degradation effect caused by pneumatic heat generation-heat conduction are considered, and the problem of prediction deviation caused by neglecting of rigid-elastic coupling and an extreme thermal environment in traditional solving is solved. According to the method, aeroelastic response analysis of the aircraft in different load stages (full load, half load and no load) can be simulated, and hot gas bomb response under the action of thrust disturbance and extreme thermal load is solved, so that the prediction capability of dynamic behaviors of the aircraft under complex working conditions is improved; and a theoretical technical support is provided for aeroelastic response servo suppression of the boosting-energy complementing gliding aircraft in a large impact / extreme thermal environment.

The invention discloses a robotized autonomous assembly system and method for large aircraft components, and the system comprises a sensing module, a decision module and an execution module, the sensing module comprises a depth camera and a point cloud registration unit which is used for estimating the relative rigid transformation of a target point cloud of the current large aircraft component relative to a source point cloud of a known assembly pose; the decision-making module is used for converting relative rigidity into a tail end target pose under a base coordinate system of the mechanical arm based on a coordinate system chain type transmission principle and rigid body pose invariance constraint; the execution module is used for receiving the target pose of the mechanical arm and planning a collision-free, smooth and efficient motion track from the current pose to the target pose; the mechanical arm executes the assembling action according to the motion trail, meanwhile, the depth camera feeds back pose data in real time, and closed-loop control is formed till assembling is completed; according to the invention, the technical problems of insufficient sensing precision, poor system flexibility, limited measurement real-time performance and splitting of each link in the existing aircraft large component assembly technology can be effectively solved.

The invention provides flexible device alignment detection equipment and a detection method thereof. The flexible device alignment detection equipment comprises a jig platform, a shaping mechanism, a main detection module and a control module. The bearing plane of the jig platform is provided with a positioning reference edge to establish a workpiece coordinate system; the main detection module obtains an unshaped first state reference image and a shaped second state reference image. The control module matches the two-state reference features under a workpiece coordinate system, obtains feature coordinates and solves initial plane rigid body transformation parameters; inversely mapping the second state feature coordinates to the first state to obtain a residual deformation quantity vector, and reconstructing a residual deformation field; and determining and normalizing an adaptive weight coefficient according to the residual modulus value, and solving by adopting weighted least squares to obtain a global alignment deviation of a shaping state relative to a workpiece coordinate system. The equipment can improve the robustness and stability of alignment calculation when in-plane deformation exists.

The invention discloses a lower limb exoskeleton man-machine synchronization self-adaptive admittance control method based on a disturbance observer, and provides a torque-sensor-free control scheme for solving the problems that an existing lower limb exoskeleton is large in intention recognition delay, high in model dependence and prone to drifting of a physical sensor. The method comprises the following steps: firstly, establishing a man-machine coupling dynamic model of a single-joint equivalent rigid body, and uniformly representing human body active torque, nonlinear friction and external load change as total disturbance of a system; secondly, constructing a three-order linear extended state observer, observing the total disturbance in real time by using a joint encoder and a control instruction, and reconstructing a man-machine interaction torque through a model-assisted disturbance separation strategy; furthermore, a variable parameter admittance controller is constructed in combination with a gait phase calculated by an inertial measurement unit, and the virtual stiffness and the damping coefficient are dynamically adjusted according to the observed interaction torque amplitude. According to the invention, accurate perception and compliant response to human body motion intentions can be realized on a low-computing-power embedded platform, the phenomenon of asynchronous man-machine motion is effectively eliminated, and the comfort and walking metabolism efficiency of a wearer are remarkably improved while the robustness of the system is ensured.

The invention relates to the technical field of geometric error evaluation of hole and shaft parts in the field of machinery, and discloses a hole and shaft part action boundary discrimination method, which comprises the following steps of: deriving a motion coefficient vector for describing radius change of each measuring point based on a tiny rigid body motion model of a surface measuring point set of a measured part; and the motion coefficients are combined into a motion coefficient matrix. Furthermore, the method establishes a discriminant inequality group based on a mutual exclusion proposition. The judgment process is realized by analyzing the rank of the motion coefficient matrix and iteratively solving an equation set formed by the maximum linear independent matrix of the motion coefficient matrix, and finally, whether the fitting cylinder is the action boundary or not is determined by judging whether the inequality set has a feasible solution or not. According to the method, the problems of complicated geometric discrimination conditions, lack of universality and the like in the existing evaluation method can be solved, and a reliable basis which is easy to realize in a stylization manner is provided for determining the action boundary of the hole-shaft part.

The present application relates to the technical fields of mechanical dynamics analysis and mechanism simulation, and discloses a guide rail impact and dynamic analysis method of a three-degree-of-freedom flat push rod cam mechanism, comprising the following steps: establishing global and local coordinate systems, and defining the push rod as a rigid body with three degrees of freedom of lateral, longitudinal and rotation; correcting the effective input displacement of the cam according to the rotation angle, and calculating the normal contact force, friction force and total cam contact moment; at the same time, monitoring the collision of the four corner points of the push rod with the guide rail, and calculating the guide rail impact force and total guide rail impact moment; and constructing coupled dynamics differential equations by comprehensively using the above forces and moments, and solving the motion state by using numerical integration. Further, the dynamics behavior of the system is identified by using Poincaré section and five-element impact mode code recognition system. The present application realizes the simulation of push rod tilting, overturning and multi-point impact, can effectively identify the periodic, bifurcation and chaotic motion state of the system, and provides theoretical support for mechanism optimization design.

This invention discloses a method and apparatus for evaluating the mechanical properties of high-voltage wiring harnesses. The method includes: constructing a rigid-flexible coupling model of the entire vehicle, comprising a rigid body model of the vehicle and a flexible cable model of the high-voltage wiring harness within the vehicle; performing a driving simulation on the rigid-flexible coupling model of the entire vehicle under target operating conditions to obtain a first motion simulation result of the high-voltage wiring harness, and then determining a first mechanical property evaluation result based on this result; performing a stress simulation on the flexible cable model based on the first motion simulation result to obtain a second motion simulation result for each fixed clip node; and performing a mechanical property simulation on each fixed clip node based on the second motion simulation result to obtain the corresponding second mechanical property evaluation result. This invention solves the technical problem that related technologies, which use a decentralized and static approach, cannot accurately evaluate the mechanical properties of high-voltage wiring harnesses, thus hindering the accurate analysis of failure modes of high-voltage wiring harnesses during long-term service.

A tracking surgery frame for tracking a patient via a surgical navigation system includes an opening for entry to an intervention region, which is arrangeable around an intervention region and fixable with or to the patient so that a geometrical relationship between the intervention region and frame does not change. A first rigid body has at least one first marker for being tracked by the navigation system. A second rigid body has a second marker for being tracked by the navigation system. At least three markers are connected to the frame. The frame provides access to and a view of the intervention region via the opening. The first rigid body is spaced further apart from the second rigid body than the first rigid body is spaced apart from a portion of the frame. The frame can be used with a navigation system, navigation method and computer-readable storage medium.

Provided are transport bags (10), (20) for transporting contents. The transport bags (10), (20) include filling ports (13), (23) for the contents and discharge ports (12), (22) for the contents, respectively. In a side view of the transport bags (10), (20), inclined regions (14), (24) are inclined from the filling ports (13), (23) toward the discharge ports (12), (22), respectively. The transport bag (20) preferably includes a cylindrical inner bag (21), a filling port (23) located at the upper end of the inner bag (21), a discharge port (22) located at the lower end of the inner bag (21), and a guide member (26) composed of a rigid body and covering the outer surface of the inclined region (24) located in the lower end region of the inner bag (21). The guide member (26) includes, on at least part of the inner surface thereof, an inclined surface (28) that is inclined toward the discharge port (22).

The purpose of the present invention is to reduce the sliding resistance of a wiring member when the wiring member enters an excess length absorbing case. This excess length absorption device for a wiring member, which absorbs the excess length of a wiring member having an internal support part, is provided with: an excess length absorption case for accommodating an excess length portion generated by the excess length in the wiring member; and a biasing unit that biases the excess length portion within the excess length absorbing case. The excess length absorbing case includes: a support portion that supports the internal support portion; and a peripheral wall surrounding the support portion with a gap therebetween, the peripheral wall having an inlet / outlet for the wiring member, the excess length portion being a portion of the wiring member disposed in the excess length absorption case through the inlet / outlet and forming a spiral around the support portion, the biasing unit including: a rigid body positioned on an outer peripheral side of the excess length portion; and a biasing member that biases the rigid body against the outer peripheral surface of the excess length portion.

A super-paramagnetic material transducer includes: a rigid body with a longitudinal central axis and two planar surfaces at each of the opposite ends of the body in the direction of the longitudinal central axis, both of these planar surfaces being substantially perpendicular to the longitudinal central axis; and at least one support channel formed in the body and in which a super-paramagnetic coil is housed, the support channel extending parallel to the longitudinal central axis and opening onto both planar surfaces. The super-paramagnetic coil is formed by a core made of super-paramagnetic around which at least one electrical conductor is wound. Furthermore, a feedback winding formed by an electric conductor is wound on the external surface of the body and along the longitudinal central axis.

This application relates to a hydraulic control optimization method, device, equipment, and medium for sector pre-assembly fixtures. It includes: establishing a global coordinate system and a sector pre-assembly fixture coordinate system, and determining rigid body transformation relationships; determining the current pose of the sector pre-assembly fixture and the target position of the sector to be transferred, and determining the initial position of the sector to be transferred; transferring the sector to be transferred from its current position to its initial position using the sector pre-assembly fixture; and, while the sector pre-assembly fixture is within a preset range, determining the gap and deviation of at least one measuring point on the sector pre-assembly fixture based on the current pose and rigid body transformation relationships, determining the target control strategy, and providing early warning and / or controlling multiple cylinder groups of the sector pre-assembly fixture. This solves the problems of high learning costs, high risk of misoperation, low adjustment efficiency, insufficient collision avoidance margin, and prominent safety hazards in heavy-duty operations in related technologies, improving the safety, efficiency, and repeatability of the transfer and alignment process.

The invention discloses a design method of an integral swing self-resetting structure for mounting a tension-compression energy-dissipation support, and relates to the technical field of civil engineering earthquake resistance, and the integral swing self-resetting structure comprises a tensile limiting device and a compression limiting device; the method specifically comprises the steps that a structural mechanical model is established, and the lateral stiffness of a traditional fixed foundation is calculated; setting a rigid body displacement ratio to determine the vertical and horizontal rigidity and strength of the support; carrying out finite element push-and-cover analysis to verify a rigid body displacement ratio; setting an additional damping ratio; carrying out seismic response spectrum analysis on the vertical seismic isolation structure; calculating the vertical natural vibration period of the structure and adjusting the rigidity according to the response spectrum; carrying out elastic-plastic time-history analysis to detect an interlayer displacement angle, acceleration and structural damage; checking the consistency of the additional damping ratio and the actual energy consumption; and finally, anti-overturning checking calculation under extremely rare earthquake is carried out to ensure that the support and the limiting device are in an elastic state. The energy dissipation capacity and anti-seismic safety of the structure can be effectively improved, and the structure is suitable for various building structures needing vertical and horizontal seismic isolation.

This invention relates to a method and system for rapidly calculating the steady-state periodic response of a rigid body flapping rotor, belonging to the field of rotor flapping response calculation technology. It utilizes a rotor region mesh to iteratively calculate the rigid body flapping angle, flapping velocity, and flow field velocity, and then calculates the rotor's aerodynamic forces based on blade element theory. The aerodynamic forces are then used to calculate the rotor momentum source term. This term is added to the momentum source term in the Navier-Stokes equations, and the rotor region mesh is updated. Finally, the aerodynamic forces are used to calculate the Faroe Islands momentum source term. n This invention updates the rotor rigid body flapping response in a loosely coupled manner. It calculates the rotor's steady-state periodic flapping response to the collective pitch control input, longitudinal periodic pitch control input, and lateral periodic pitch control input. By loosely coupling the rotor momentum source term and the rotor rigid body flapping response, this invention comprehensively considers the influence of aerodynamic components on the flow field, effectively improving computational efficiency.

The invention relates to a hydraulic control optimization method and device for a sector preassembling tool, equipment and a medium. Comprising the following steps: establishing a global coordinate system and a sector preassembled tool coordinate system, and determining a rigid body transformation relation; determining the current pose of the sector preassembling tool and the target station of the to-be-transferred sector, determining the initial position of the to-be-transferred sector, transferring the to-be-transferred sector from the current position to the initial position through the sector preassembling tool, and transferring the to-be-transferred sector from the current position to the initial position on the basis of the current pose and the rigid body transformation relation under the condition that the sector preassembling tool is within the preset range. And determining a gap and a deviation value of at least one distance measurement point on the sector preassembling tool, determining a target control strategy, and carrying out early warning reminding and / or controlling a plurality of oil cylinder groups of the sector preassembling tool. Therefore, the problems of high operation learning cost, high misoperation risk, low adjustment efficiency, insufficient anti-collision margin and prominent heavy-load operation potential safety hazards in the prior art are solved, and the safety, efficiency and repeatability of the transfer and alignment process are improved.

The application provides a rigid body rotational inertia product measurement system and method based on point cloud registration, and relates to the field of inertia product measurement.The system comprises a torsion pendulum measurement platform, a structured light 3D model scanning device and a computer.The torsion pendulum measurement platform is used for loading a measured object and performing torsional vibration on the measured object.The torsion pendulum measurement platform is arranged in the scanning range of the structured light 3D model scanning device.The structured light 3D model scanning device is used for acquiring point cloud data and a CAD model of the measured object.The structured light 3D model scanning device is in communication connection with the computer, and the acquired point cloud data and CAD model of the measured object are transmitted to the computer.The computer is used for calculating the rotational inertia product of the measured object according to the point cloud data and the CAD model of the measured object.The application can accurately calculate the rotational inertia and the rotational inertia product of the measured object.

To provide a working vehicle capable of inexpensively constituting a belt attaching-detaching part capable of replacing a belt without disassembling a fan shroud with a rigid body structure, and capable of reducing even a maintenance work cost.SOLUTION: The fan shroud 58 is integrally provided with a peripheral 58b formed wide on the outer periphery of a box-shaped main body 58a formed with a ventilation hole 58c so as to form a series of cylindrical bodies, and one of the peripheral 58c is provided with a belt attachment / detachment portion 60 including a fan belt 41, a maintenance hole 61 formed as a long hole into which fingers can be inserted, and a hole lid 62 capable of opening and closing the maintenance hole 61.SELECTED DRAWING: Figure 5

The application discloses a node processing review and precision improvement method based on three-dimensional laser scanning, relates to the technical field of digital manufacturing and steel structure engineering precision control, and comprises the following steps: through multi-scale structure feature identification, basic attributes and topological relationship modeling are combined, effective guidance of design information to the whole detection process is realized, through enhanced feature tree driven scanning path planning combined with multi-view point cloud fine splicing strategy, the collaborative mechanism of scanning implementation and design features is embodied, high-quality data acquisition of key functional features is realized, through multi-scale feature corresponding set construction combined with an adaptive nonlinear least square optimization model, the idea of multi-level constraint collaborative participation registration is embodied, high-stability rigid body transformation solution is realized, through deviation field construction combined with function area confidence and effective error index calculation, the ability of detection result transformation to engineering decision is embodied, and the scientificity of correction and rework decision is improved.