49 results about "Rigid body rotation" patented technology

The invention provides an on-line monitoring method of overall three-dimensional deformation of wind wheel blades in working states. The on-line monitoring method comprises the steps of selecting a wheel hub center as a fixed mark point, selecting another mark point at the root of each blade, and adopts marks in different shapes before a wind generator unit operates, obtaining overall three-dimensional coordinates of the wind wheel blades in static states with two digital cameras, when the wind generator unit operates, determining rigid body rotation angles of the wind wheel blades according to relative positions of the mark points in the working states and the static states, calculating to obtain the three-dimensional coordinates of the deformed wind wheel blades in the working states according to image plane coordinates after removing rigid body rotation displacement, and obtaining overall three-dimensional displacement values and strain values of the wind wheel blades in the working states according to differences of the three-dimensional coordinates before and after the deformation of the wind wheel blades. The method has the on-line, non-contact, overall and three-dimensional advantages and the like, can obtain overall three-dimensional displacement and strain of the wind wheel blades in the working states, and achieves monitoring of the deformation of the wind wheel blades in the working states.

A three-dimensional non-contacting angular motion sensor, based on magnetometry, has been developed for velocity feedback in the ball wheel mechanism, which serves as the drivetrain for a class of omnidirectional mobile platforms. More generally, this scheme tracks rigid-body rotation about a fixed point with an undefined axis of rotation. The approach involves tracking the time-varying magnetic field of a permanent disc magnet, embedded at the center of the sphere. This data is then used to determine the absolute orientation of the magnet axis. Finally, an approach based on the natural invariants of rigid-body motion is used to determine the instantaneous axis of rotation and the angular speed of the sphere about this axis.

The invention relates to a plane component deformation decomposition and vibration mode identification method based on an orthogonal decomposition theory. The method comprises the following steps: step 1, the plane deformation of a four-node square unit is formed by laminating eight basic deformation such as the rigid body displacement in an x direction, the rigid body displacement in a y direction, the extruding deformation in the x direction, the extruding deformation in the y direction, the bending deformation in the x direction, the bending deformation in the y direction, the shear deformation and the rigid body rotation displacement; targeting for the four-node square unit, an orthogonal decomposition method is adopted to respectively establish the basic deformation vector of each of the rigid body displacement in the x direction, the rigid body displacement in the y direction, the extruding deformation in the x direction, the extruding deformation in the y direction, the bending deformation in the x direction, the bending deformation in the y direction, the shear deformation and the rigid body rotation displacement. The method is also applicable when the structure of a plane component is divided into large units, the calculation workload is alleviated; moreover, the bending deformation and the shear vibration mode can be identified, and the stress situation and vibration type inside a component can be more accurately and completely reflected.

The invention discloses a virtual reality interaction method based on Unity 3D. The method comprises the following steps: establishing communication connection with an optical motion capture system; receiving rigid body position data and rigid body rotation data of a real object in a real scene captured by the optical motion capture system in real time through a VRPN protocol; carrying out left-right hand coordinate system transformation on the rigid body position data and the rigid body rotation data, wherein a right-hand coordinate system is adopted in a real scene, and a left-hand coordinate system is adopted in a virtual scene; when a visual angle picture of the virtual object in the virtual scene is generated through rendering, synchronously mapping the rigid body position data and the rigid body rotation data of the real object after coordinate system transformation to the virtual object, so that the virtual object simulates the action of the real object. The invention further discloses a virtual reality interaction device and equipment based on Unity 3D and a computer readable storage medium. According to the invention, simulation interaction of a real scene is realized based on Unity 3D, the interaction mode of Unity 3D is expanded, and the use experience of a user is improved.

The invention discloses a hybrid interlayer crack propagation analysis method for a composite laminated plate, and relates to the field of composite material laminated plate interlayer failure, the analysis method comprises the following steps: 1, establishing a laminated plate model containing general layered cracks; 2, a single DCB test piece crack propagation analysis model is established; 3, establishing a single ENF test piece crack propagation analysis model; and 4, establishing a crack propagation analysis model of the mixed crack MMB test piece; the method disclosed by the invention issuitable for analyzing the crack propagation process of the composite material laminated plate test piece in a single and mixed layered fracture mode; rigid body rotation around a simply supported constraint point at the right end of a test piece and a softening behavior of a crack tip are simultaneously considered in a mixed fracture mode, and the method can accurately and reliably predict a general mixed layered crack propagation behavior, is suitable for engineering practice, and provides a reliable cross inspection tool for numerical simulation at the same time.

The invention relates to a behavior identification method based on integration depth typical time wrapping and related correction. The behavior identification method solves the technical problems of low identification accuracy degree and long consumed time, and comprises the steps of: expressing a behavior of a human body as rigid body displacement, decomposing the rigid body displacement into rigid body translation and rigid body rotation, and expressing the rigid body displacement by means of a homogeneous matrix Lie group SE (3), wherein Lie Algebra is SO(3); establishing a skeleton model C(t) according to acquired skeleton data, expressing a displacement mapping relation as the homogeneous matrix Lie group SE (3), establishing the skeleton model C (t) based in a Lie algebra relative feature description method, and subjecting the skeleton model C(t) to difference value processing; aligning the skeleton model C(t) by adopting a integration depth typical time wrapping method; and correcting aligned feature samples by utilizing correlation features, and classifying the corrected feature samples by means of a support vector machine. The behavior identification method solves the problems, and is applied to the behavior identification of 3D skeletons.

The invention discloses an automobile powertrain system rotational inertia synthetic method. The method comprises the steps of inputting the known parameters including the mass, center of mass, inertia and eulerian angle of an engine and a gear box into an EXCEL so as to facilitate data import and correction; obtaining the coordinates of the main center of mass obtained after synthesis according to the mass and center of mass of the engine and the gearbox by means of the method for solving the center of mass in theoretical mechanics; establishing a coordinate system the orientation of which is parallel to that of a main coordinate system according to the coordinates of the main center of mass; expressing vectors with a coordinate matrix, establishing the relationship between the coordinate matrixes of the same vectors under different coordinate systems, and deducing the relationship between inertia matrixes under different coordinate systems by means of correlation theoretical methods of the linear algebra, namely establishing the relationship between rigid body rotation inertia and the product of inertia under different coordinate systems; calculating a synthesis result by means of a corresponding computer language compile program according to a deduced matrix expression. According to the method, deduction is conducted in the matrix form, briefness and visualization are achieved, the conclusion is in a quite brief form, and a solution can be obtained easily by means of the computer language.

The invention relates to a research method for marine deepwater risers, and particularly relates to a method for analyzing the out-of-plane motion of a steel catenary riser. By using the method disclosed by the invention, an improvement on the existing technique for analyzing the out-of-plane motion of a steel catenary riser is performed, the rigid body motion of the out-of-plane motion of a steel catenary riser is taken into consideration, an analytical mode of the out-of-plane motion of a steel catenary riser is built, and the rigid body rotation of the out-of-plane motion of a steel catenary riser is added, so that the analysis on the out-of-plane motion of a steel catenary riser is more consonant with an actual motion state.

A method to balance a crank drive of an internal combustion engine comprising: using a balancer unit comprising a first balance weight and a second balance weight serving as counterbalance; rotating the first and second balance weight at an engine rotation speed when a crankshaft rotates at the engine rotation speed; rotating the first balance weight in a same direction as the crankshaft; rotating the second balance weight in an opposite direction to the crankshaft; arranging the first balance weight and the second balance weight such that a resulting balancing moment about a velocity pole of a 1st order of a rigid body rotation of a drive unit at least partially balances a rotary movement about a velocity pole provoked by a resulting mass moment of the 1st order, an external effect of the resulting mass moment of the 1st order being at least partially balanced.

The invention provides a rotating shaft direction and rotating angular velocity resolving method for a moving rotating object, which comprises the following steps of: firstly, registering an adjacentpoint cloud at the moment by using a nearest point iteration point cloud registration algorithm, and constructing a local track matrix by using a registration matrix; secondly, point position information is obtained according to a local track matrix, point track fitting is carried out, the speed of a certain point at a certain moment is solved, and finally an equation is established according to the rigid body rotation physical process to carry out rotation parameter resolving; according to the method, dependence on feature points is avoided, and the motion condition of a target at a certain moment is described by using a local track matrix; good robustness is achieved on point cloud local loss caused by self-shielding of the target, and errors caused by incomplete feature point tracks inthe sequence point cloud are avoided; the method can effectively solve the rotating shaft and the rotating angular velocity, especially when the angular velocity of the rotating object is variable motion, the solving result can better track the change of the set angular velocity, the solving precision is higher, and the solving advantage is more obvious.

The invention discloses a method for evaluating the protection effect of a newly-built tunnel grouting ring on an existing shield tunnel. The method comprises steps of a three-dimensional coordinate system and a grouting ring mechanical calculation model being established according to the relative positions of a newly-built tunnel, an existing tunnel and the grouting ring; according to the established grouting ring mechanical model, the influence process on the surrounding soil layer being simulated through volume expansion of the grouting ring, and a formula for solving the additional stressof the surrounding soil layer caused by expansion of the grouting ring being deduced by utilizing a random medium theory; considering the influence of excavation of the newly-built tunnel and volume expansion of the grouting ring, and calculating the total vertical additional stress at the axis of the existing tunnel under the combined action of the excavation and the grouting ring; substituting the total vertical additional stress into the shear slab staggering and rigid body rotation cooperative deformation model to obtain the vertical displacement of the existing tunnel, and evaluating therationality of a tunnel underneath pass scheme and a grouting ring setting scheme according to the obtained vertical displacement of the tunnel. The method can be designed and optimized through repeated adjustment of parameters and multiple times of substitution checking calculation.

The invention discloses a method and a device for calibrating an orthodontic anchorage nail, belongs to the technical field of medical auxiliary instruments, and aims to solve the problem that an implantation position is deviated due to the fact that a tip position cannot be obtained in an implantation process of an anchorage nail in the prior art. The calibrating method disclosed by the inventioncomprises calibrating the tip of an anchorage nail and calibrating the axis direction of a central axis of the anchorage nail is calibrated. A process of calibrating the tip of an anchorage nail comprises the following steps: assembling a calibrating device, tracking position information of a tracking rigid body under an optical tracking device coordinate system so as to obtain a centroid under match of a V-shaped concave cone, and converting the centroid to a rigid body tracking coordinate system to use the centroid as the position coordinate of the tip of the anchorage nail. A process of calibrating the axis direction of the central axis of the anchorage nail comprises the following steps: obtaining a space coordinate of the rotation center of the tracking rigid body under the clampingstate of different positions of a long handle; fitting a straight line by a least square method; converting the central axis of the long hand to the tracking rigid body coordinate system; and normalizing the direction of the central shaft to use the normalized direction as the direction of the central axis of the anchorage nail.

The invention provides a calibration system for a gyroscope installation error, and a calibration method thereof. The calibration system comprises an error calibration platform, an error calibration rigid body rotation table, a data transmission device and an error calibration upper computer, wherein the error calibration platform rotates and drives the error calibration rigid body rotation tableto rotate at an even speed after the error calibration platform is electrified; the error calibration rigid body rotation table drives an error calibration gyroscope to rotate; the speed information of the error calibration gyroscope is transmitted to the error calibration upper computer through the data transmission device; the error calibration upper computer displays the installation error angle value of the error calibration gyroscope according to the speed information; and according to the installation error angle value, the installation error of the error calibration gyroscope is calibrated so as to realize quick and accurate compensation.

The invention discloses a magnetic type combined rigid body which comprises a first rigid body and a second rigid body. The first rigid body is a straight rod with mass evenly distributed. The second rigid body is magnetic and movably adsorbed to the first rigid body. The center of mass of the second rigid body is located on the first rigid body. The magnetic type combined rigid body is simple in structure, practical, convenient to use, beneficial to combination of theories and experiments and capable of deepening understanding of the rigid body rotation law.

The invention discloses a high-order attitude enhancement method based on angular rate input, and belongs to the field of strapdown inertial navigation. According to the method, angular rates in a previous attitude updating period and a current attitude updating period are utilized, firstly, Lagrange interpolation is carried out on the angular rates, integration is carried out in the current attitude updating period to estimate angular increment, and then a linear combination of angular rate binary products is utilized to estimate a second-order rotation vector term in a non-exchangeable error, and then, a third-order rotation vector item in the non-exchangeable error is estimated by utilizing a linear combination of angular rate ternary products, and finally a rotation vector in an attitude updating period with the obtained approximate values of the angular increment, the second-order rotation vector item and the third-order rotation vector item, so that the non-exchangeable error caused by rigid body rotation is effectively reduced; and the attitude calculation precision is further improved.

The invention provides a rigid body rotation dynamics experiment device, and relates to a mechanics experiment device. The problem that in the prior art, a simple rigid body rotation dynamics experiment device is lacked is solved. The experiment device comprises an X-axis, a Y-axis and a Z-axis which are perpendicular to one another, x-axis rotational position is fixed, x-axis is connected with anX frame, the X frame is rotationally connected with a Z frame through a Z shaft; wherein the Z frame rotates in the X frame, the Z frame is rotatably connected with a Y frame through a Y axis, the Yframe rotates in the Z frame, the Y frame is an annular frame, two large mass blocks are arranged on the Y frame in a central symmetry mode, and two small mass blocks are arranged at the Y-axis connecting position of the Y frame in a central symmetry mode. According to the invention, the three-degree-of-freedom rotating device is used for providing a simulation model for the spin dynamics researchof the rigid body, so that the phenomenon of a rigid body spin stabilization intermediate shaft can be clearly observed; the mass block is arranged in a position-adjustable mode, so that the functions of the experimental device are increased.

The invention discloses an evaluation method for a grouting deviation correction effect for horizontal deformation of a shield tunnel, and the method comprises the steps: building a grouting volume expansion mechanical calculation model, and deducing a calculation formula of the simplified horizontal additional stress of any point in a soil layer caused by grouting based on a mirror image method;with a grouting area uniform expansion model, obtaining the volume of a grouted soil body after expansion according to the amount of grout injected into a sleeve valve pipe and the volume expansion rate of a grouting ring, and substituting the volume into the calculation formula to obtain the horizontal additional stress of a to-be-corrected tunnel; substituting the horizontal additional stress ofthe to-be-corrected tunnel into a tunnel horizontal displacement formula through a tunnel shearing dislocation and rigid body rotation collaborative deformation calculation model, so as to obtain thetunnel horizontal displacement correction amount of any point in the calculation range; and performing evaluating according to the horizontal displacement deviation rectifying amount of the tunnel, referring to the I-level control standard in Technical Regulations for Safety Protection of Urban Railway Traffic Structures, if the deviation axis center of the tunnel is less than 5mm, determining that the tunnel deviation is reasonable, otherwise, determining that the tunnel deviation is unreasonable.