36 results about "Orthogonal coordinates" patented technology

The application belongs to the technical field of aero-engine fuel control and discloses a three-dimensional space oil passage modeling method for a fuel control device shell. The method comprises the following steps: taking a set cross section of a pipeline where an oil passage hole is located as a reference, taking a center of the cross section as a coordinate origin, and establishing a three-dimensional orthogonal coordinate system OXYZ with the cross section as an XOY plane; the oil passage hole is located above the set cross section; the XOY plane in the three-dimensional orthogonal coordinate system is offset upward to form a reference plane 1; a two-dimensional circle model is established on the reference plane 1; a reference axis with the center of the circle as an end point is established on the two-dimensional circle; the reference plane is rotated by a preset angle with the reference axis as a rotation axis to form a reference plane 2, a target hole is established on the reference plane 2, and the positioning reference of the target hole is the center of the two-dimensional circle, so that a modeling result of a three-dimensional oil passage hole is obtained, and accurate positioning of drawing marking is realized by using an orthogonal positioning method.

The application provides a light measurement equipment simulation training method and system based on dynamic trajectory modeling, relates to the technical field of simulation training, and comprises the following steps: acquiring a plurality of components of a light measurement equipment, and constructing an initial three-dimensional component model; performing parameter configuration on the initial three-dimensional component model based on initial parameters of the plurality of components; determining a target theoretical trajectory, and performing dynamic trajectory modeling through a plurality of spatial orthogonal coordinate systems; calculating a sun elevation angle and an azimuth angle of the sun relative to a target point; mapping to the initial three-dimensional target model for simulation training, and determining a plurality of simulation scenes; performing simulation rehearsal on the light measurement equipment, adjusting the simulation rehearsal result for deviation, and obtaining a three-dimensional target model. The application solves the technical problem that, in the prior art, due to the lack of adaptability to complex scenes and environmental changes, it is difficult to reproduce scenes, and the simulation result has a large deviation. Through the implementation of high-precision simulation scene construction, the simulation precision of the light measurement equipment is improved.

The invention relates to the field of neuroscience experiments and biomedical engineering, and discloses a brain stereotactic method and system based on a turtle skull zero point, and the method comprises the following steps: taking a repeatedly recognizable bony mark point of a turtle skull as a zero point; a plane parallel to the reference plane of the brain stereotaxic instrument is established as an XY plane, and an axis parallel to the zero point probe is taken as a Z axis. Further, the invention provides a coordinate conversion method for converting target point coordinates in a three-dimensional image into a coordinate system of a stereotaxic instrument, which comprises the following steps of: positioning a zero point and a reference point in the image, determining a Z-axis direction, constructing an orthogonal coordinate base, and calculating rigid body transformation from an image coordinate system to a stereotaxic coordinate system; therefore, the three-dimensional displacement, the needle inserting depth and the track parameters for the movement of the positioning arm are output. The device can be used in cooperation with an existing brain stereotaxic instrument suitable for turtles, high-repeatability positioning of turtle brain region electrode implantation / injection is achieved, and the consistency and efficiency of cross-individual and cross-batch experiments are improved.

The embodiment of the invention provides a space bounding box calculation method for a three-dimensional model. The method comprises the steps that continuous parameterized expression of the surface of a target three-dimensional model on a parameter domain is determined; according to the continuous parameterized expression, analyzing a plurality of profile curves obtained by projecting the target three-dimensional model on a plurality of mutually orthogonal coordinate planes in a three-dimensional coordinate system; according to the parameterized expressions of the plurality of profile curves, determining two-dimensional bounding boxes respectively corresponding to the plurality of profile curves on the corresponding coordinate planes; and performing extreme value selection operation on the boundary value of the two-dimensional bounding box in the coordinate axis direction to generate a three-dimensional space bounding box of the target three-dimensional model. A projection profile curve is directly analyzed through continuous parameterization expression, the geometric boundary of the model is locked in mathematics essence, the defect that extreme points are missed in discrete sampling is avoided, and the calculation precision is improved; and three-dimensional extremum search is converted into two-dimensional profile curve analysis and two-dimensional bounding box construction on a plurality of orthogonal coordinate planes, so that the calculation complexity is reduced.

The invention relates to the technical field of computational chemistry and drug screening, and discloses a fluorinated derivative screening method based on computer-aided design, which comprises the following steps: acquiring an initial binding conformation of fluorine-containing molecules and a target system, and constructing a follow-up local orthogonal coordinate system by taking the axial direction of a fluorocarbon bond as a reference; projection coordinates of the environmental particles relative to the fluorocarbon bonds are calculated and mapped as a spherical coordinate index, a preset anisotropic potential energy surface grid is called, and a potential energy value is calculated through interpolation; the method comprises the following steps: generating an anisotropic correction term, monitoring the modulus length of the energy gradient in real time, and when the modulus length of the energy gradient exceeds a sensitive threshold value, adaptively and nonlinearly reducing a sampling step length and executing high-frequency local sampling in a sensitive area. The problem of false negative activity prediction caused by insufficient sampling when a traditional equal-step algorithm is used for processing anisotropic distribution of fluorine atom electron clouds is solved, and the recognition precision and screening efficiency for weak directional interaction such as halogen bonds are improved.

This invention discloses a planar target measurement and correction method and system based on RGB-D data, comprising: acquiring a scene RGB image, a depth matrix, and camera intrinsic parameters; selecting a Region of Interest (ROI) and converting the ROI depth data into a 3D point cloud using the camera intrinsic parameters; obtaining the target plane equation through robust plane fitting and constructing its local orthogonal coordinate system; establishing an inverse mapping from image pixels to local plane coordinates based on the camera intrinsic parameters, the plane equation, and the local coordinate system to generate a corrected image with physical scale information; determining the target to be measured on the corrected image, calculating the pixel Euclidean distance, converting the pixel distance into the actual physical length based on the scale information of the corrected image, and outputting the measurement result; this invention can overcome the bottlenecks of traditional technologies, achieve high-precision single measurement, is computationally efficient and easy to operate, significantly improves the user experience, ensures the high quality and authenticity of the corrected image, has a wide range of applications and good device compatibility, and is easy to promote and popularize.

The invention relates to a method for laser treatment of a timepiece component (10), said method comprising an operation for treating a surface of said timepiece component (10) recorded in a standard orthogonal XYZ coordinate system, in which a laser (20) is controlled to emit a laser beam (21) and to move a focal point (210) of said laser beam (21), the invention relates to a method for scanning a surface to be processed (100) on a timepiece part (10) in response to a control command from a computer program, in order to follow a scanning strategy comprising a plurality of paths (31), each path having a component in a Z direction and a component in at least one of an X direction or a Y direction, the scanning strategy is defined such that the energy density emitted by the laser beam (21) varies across the surface (100) to be treated.

This application relates to a method for locating anchor points of orthodontic retainer wires, belonging to the field of orthodontics. The method includes: reading tooth data of adjacent tooth pairs for which wire structures need to be placed, and calculating global reference features; analyzing the global reference features to obtain the labial contact points of adjacent tooth pairs; constructing an orthogonal coordinate system; determining the saddle points where the wire crosses adjacent tooth pairs based on the orthogonal coordinate system, and calculating the first and second characteristic anchor points of the adjacent tooth pairs; setting a cross-sectional point set, and calculating the first vertex, bottom point, and second vertex of a U-shaped path based on the labial contact points of the canines and the cross-sectional point set to construct a U-shaped path; and constructing a three-dimensional coordinate point set for the wire anchor points. This application solves the problem of low anchor point positioning accuracy and efficiency during orthodontic retainer fabrication due to reliance on manual operation by technicians and the lack of standardized parameters.

A three-dimensional sensor control device performs processes of acquiring orthogonal coordinates of data points found in a plurality of photograph frames photographed by at least one three-dimensional sensor with a fixed photographing range and converting the orthogonal coordinates of the data points into polar coordinates using a first formula for conversion from orthogonal coordinates to polar coordinates The device then performs searching each sub-region of the photographing range to locate a set of polar coordinates representing a farthest data point that is located farthest in distance from the three-dimensional sensor in a respective sub-region and converting the polar coordinates of a collection of the farthest data points back into orthogonal coordinates using a second formula for conversion from the polar coordinates to the orthogonal coordinates, The device outputs environment map data of the photographing range using the orthogonal coordinates of the collection of the farthest data points.

The application relates to a strapdown inertial navigation method of a small mobile object. The essence of the application is that N sensors are installed on a cubic mechanical base, and each sensor contains n physical quantity transducers. The sensitivity axes of the transducers located on the side surface of the cube are oriented at an angle to the surface of the bottom face of the cube. The output signals of the transducers are converted into signal projections on the Xo, Yo and Zo axes of the orthogonal coordinate system with a proportional factor. The Xo and Yo axes are oriented along the diagonal of the top face of the cube, and the Zo axis is perpendicular to the center of the face. The received signals are summed, and the navigation parameters of the object motion are calculated. The technical effect is to improve the determination accuracy of the navigation parameters of the object.

The invention discloses a time migration method for a three-dimensional pre-stack wave equation in an imaging ray domain, which relates to the technical field of exploration geophysics and comprises the following steps of: deducing a bidirectional acoustic wave equation in an imaging ray coordinate system based on a Riemann wave field extrapolation theory in a three-dimensional semi-orthogonal coordinate system; an equation is directly solved by adopting a finite difference method, extrapolation of a seismic source and a receiving end wave field is achieved, and errors caused by Green function approximation in a traditional migration method are avoided; and generating a pre-stack time migration result by applying a zero-lag cross-correlation imaging condition. Through first-order linear disturbance approximation, an accurate three-dimensional time-depth conversion partial differential equation set is simplified into an optimized layer stripping algorithm, and a corresponding equation suitable for a weak transverse velocity change medium is deduced. According to the invention, the working process of three-dimensional wave equation time migration is realized in an imaging ray coordinate system, and an accurate seismic imaging result is generated; two-dimensional plane hypothesis limitation is avoided, and high-precision imaging technical guarantee is provided for seismic data processing of a complex structure area.

This invention discloses a ship attitude measurement method based on a quadrangular frustum infrared sensor array. The method includes: installing a quadrangular frustum base on a top platform directly above the ship's center of gravity, ensuring its bottom surface is parallel to the XOY plane of the ship's coordinate system; arranging a set of mid- and long-wave infrared sensors on each of the four sides, with the planes containing the bow-stern and port-starboard sides being orthogonal to each other; during measurement, obtaining the corresponding normal vectors from the four sides and constructing two sets of orthogonal sensor coordinate systems using the right-hand rule; based on the mapping relationship between the sensor coordinate system and the ship's coordinate system, deriving the mathematical expression of the sensor-observed target in the ship's coordinate system through rotation matrix transformation, thus realizing the ship's attitude angle calculation. This invention proposes a multi-directional infrared-assisted ship attitude measurement method with a standardized structure, clear coordinate relationships, and easy calibration. It is highly scalable and can provide high-precision, robust attitude measurement for ships in complex sea conditions.

The application provides a motor energy-saving and consumption-reducing intelligent management method and system based on a cloud control platform, which comprises the following steps: collecting single-machine operation data and group-machine operation data at an edge end; solving parameter error criteria by using a sparse inversion matrix based on the group-machine operation data on a cloud control platform; calculating real physical parameters of a target motor including real flux linkage values and real inductance matrixes by combining the parameter error criteria and the single-machine operation data; calculating cross-coupling strength between d-axis current and q-axis current based on the real physical parameters, and generating a conformal correction matrix in a non-orthogonal coordinate system according to the cross-coupling strength; constructing a simulation environment on the cloud control platform and backtesting the real physical parameters and the conformal correction matrix by using the single-machine operation data; and driving the target motor to operate based on the real physical parameters and the conformal correction matrix by a motor controller at the edge end if the energy efficiency improvement index and the stability index are verified. The application has the effect of effectively reducing the energy consumption of the group motor.

The invention relates to a method and system for detecting an object in a blind spot. The present disclosure relates to a method (200) for object detection in at least one blind spot (10) around a vehicle (20), comprising: capturing (202) image data of at least one area around the vehicle (20) at least partially covering the blind spot (10); at least partially processing (206) the obtained image data to locate at least one object in the obtained image data; at least partially converting (208) the processed image data into corresponding circumferential coordinates, the corresponding circumferential coordinates being defined with respect to a viewpoint at which the image data is obtained; transforming (210) the transformed circumferential coordinates at least partially into corresponding orthogonal coordinates, the corresponding orthogonal coordinates relating to an orthogonal viewpoint with respect to the blind spot (10); movement of at least a portion of the object relative to the blind spot (10) is detected (212) based at least on at least a portion of the transformed orthogonal coordinates. The disclosure also relates to a system (100) for object detection in a blind spot (10) around a vehicle (20).

A cylindrical element (1) consists of a fiber-reinforced plastic which exhibits a relationship expressed by formula 2 when a stress-strain relationship equation in an XY plane as in formula 1 is expressed in an orthogonal coordinate system O-XYZ, where an origin O is a center point in the thickness direction of a small element (10) of the cylindrical element (1), the X-axis runs along a tangential direction of a cylinder, the Y-axis runs along the direction parallel to the axial direction of the cylinder, the Z-axis runs along the radial direction of the cylinder, σ is a stress vector, ε is a strain vector, τ is a shear stress, γ is a shear strain, and an element Q ij is an element of the i-th row and j-th column of a plane stiffness matrix Q. { σ x σ y τ xy} ≡ { σ} = [ Q 11 Q 12 Q 16 Q 12 Q 22 Q 26 Q 16 Q 26 Q 66 ] { ε x ε y γ xy} ≡ [ Q ] { ε} Q 12 Q 26 − Q 16 Q 22 ≠ 0

The application relates to a method for quickly and batchly positioning target pixel positions based on a SAR image, which comprises the following steps: reading a SAR data file, judging whether the SAR image contains a target through a vector outer product method, converting a target point and a vertex of the SAR image from an earth coordinate system to an orthogonal coordinate system, calculating a target position relative to a SAR image width and an azimuth width through a geometric method, so as to obtain a rough value of a pixel position of the target point, and calculating the target pixel position through a bilinear interpolation method. The method can quickly and batchly position the target pixel positions, and the efficiency is greatly improved.

The application provides an image cutting device. The image cutting device comprises a printing end, a cutting end and a controller. The printing end is used for printing an image and a position mark on a paper. The cutting end is used for cutting the paper, and the cutting end is provided with an image sensor and a cutting assembly. The image sensor is used for identifying the position mark. The controller detects the boundary of the paper through the image sensor, and then controls the cutting assembly. The application introduces the image sensor into the cutting end to identify the position mark. The controller can detect the boundary of the paper in the X axis and the Y axis based on the position mark, so as to re-determine the orthogonal coordinate system of the image printing, improve the alignment accuracy between the printing end and the cutting end, and realize high-precision image cutting.

This invention relates to a method, system, and computer-readable medium for establishing a satellite-to-ground link for a solar observation satellite. The method includes: establishing a solar pointing coordinate system OXYZ based on the solar vector originating from the satellite's center of mass and the ecliptic plane normal vector originating from the satellite's center of mass, where O represents the satellite's center of mass, the X-axis points to the solar vector, the Y-axis points to the direction of the vector obtained by the cross product of the ecliptic plane normal vector and the solar vector, and the Z-axis forms an orthogonal coordinate system with the X-axis and Y-axis; calculating a first angle and a second angle between the center lines of the data transmission antenna beams on the solar observation satellite based on the solar pointing coordinate system OXYZ; and controlling the attitude of the solar observation satellite to keep the first angle within a first preset range and the second angle within a second preset range, thereby ensuring that the satellite-to-ground link of the solar observation satellite is effective throughout its orbital period, improving the reliability of the solar observation satellite's operation.

The present invention provides an imaging optical system capable of acquiring wide-angle image data. [Solution] An imaging optical system configured such that, in an xyz orthogonal coordinate system, a light ray traveling in the z-axis direction within a first plane perpendicular to the x-axis, whose path is contained within the first plane, is the principal ray, and a parallel beam of light incident on the first reflecting surface is focused onto the image plane, and the path of the beam of light incident on the second reflecting surface and the path of the beam of light reflected by the third reflecting surface intersect, wherein the focal length of the entire optical system along the path of the principal ray in the first plane is fy, the combined focal length of the second and third reflecting surfaces is fy23, the focal length of the entire optical system along the path of the principal ray in a plane containing the path of the principal ray and perpendicular to the first plane is fx, and the combined focal length of the second and third reflecting surfaces is fx23. 1.05 <fy23 / fx23<1.5···(1) 1.5 <fy / fx<2.2···(2) It satisfies the condition.

The application discloses a kind of multi-fingered dexterous hand self-adaptive conformal control methods for soft slippery pig liver grabbing, to solve the problem of grabbing breakage and slip caused by extremely wet slippery and easily damaged pig liver, the application first constructs and visual guidance through orthogonal coordinate system, establish the preliminary grabbing configuration adapted to the irregular contour of pig liver;Then the dexterous hand is configured as low impedance state, drive finger along the normal compliance closure of pig liver surface, use contact reaction force to induce passive slip and roll of finger palm, realize the geometric conformation from point contact to surface contact;Again, through visual geometric shape closure criterion (fingertip depth across equator and envelope centroid) Trigger smooth variable stiffness locking based on balance point reset, the flexible posture is solidified as rigid grabbing structure in situ, and the dependence on friction is converted into geometric constraint.The application overcomes the risk of low friction slip under the premise of avoiding tissue stress damage, realizes the stable and non-destructive grabbing of soft slippery pig liver.

The invention provides a gravity center adjusting method, and belongs to the technical field of equipment test, and the method specifically comprises the steps: designing water tank distribution point positions on a test platform, building a rectangular coordinate system parallel to the horizontal direction of the test platform, and building a database; the gravity center positions of the water tanks on the water tank distribution point positions in different states of the test platform are calculated, a database is formed, and the database comprises the states of the water tanks when the test platform is in multiple different gravity center positions under multiple loading weights; and according to the needed loading weight and the needed gravity center position, water is injected into the water tanks according to the states of the water tanks on the corresponding water tank distribution point positions in the database. According to the processing scheme, the gravity center adjusting efficiency and the adjusting range are improved.

In an orthogonal coordinate system O-XYZ in which the center position in the thickness direction of the minute elements (10) of the cylindrical member (1) is defined as an origin O, the tangential direction of the cylinder is defined as the X axis, the direction parallel to the axial direction of the cylinder is defined as the Y axis, and the radial direction of the cylinder is defined as the Z axis, the stress vector is set as sigma, the strain vector is set as epsilon, and the shear stress is set as tau. The cylindrical member (1) is formed from a fiber-reinforced plastic that satisfies the relationship represented by formula (2), where [gamma] is the shear strain, and Qij is the i-row j-column component of the in-plane rigid matrix (Q), and the stress-strain relational expression in the XY plane is represented by formula (1): [Mathematical formula (1)] [Mathematical formula (2)] [Mathematical formula (1)] [Mathematical formula (2)] [Mathematical formula (2)] [Mathematical formula (2)].

The application discloses a zero-range line direction multi-time maneuver penetration method, which comprises the following steps: taking the maneuver times, maneuver time and maneuver direction of a penetration warhead as optimization design variables, taking the zero-control miss distance, shift point deviation and fuel consumption as optimization indexes, and establishing a penetration trajectory optimization problem description model; designing the initialization stage, search stage and inertia weight of a PSO algorithm based on the optimization design variables of the maneuver times and maneuver time and the dimension uncertainty problem; converting the penetration trajectory optimization problem description model to a non-orthogonal coordinate system, deriving a free flight trajectory analytical solution, and combining the analytical method with the numerical method to quickly solve the zero-range line direction on the basis; and using the designed PSO algorithm to take the solved zero-range line direction as the maneuver direction to optimize the penetration trajectory of the multi-time maneuver. The application reduces the dimension of the optimization design variables, improves the penetration trajectory optimization efficiency, and can obtain the expected effect in a short time.

The invention discloses a method for calculating radial and lateral expansion area source items of a disc type rotary detonation engine, which comprises the following steps of: establishing control equations in x and y directions through mass conservation, momentum theorem, energy conservation, chemical reaction component transport equations and the like, further deducing the expansion area source items in the x and y directions, and calculating the radial and lateral expansion area source items of the disc type rotary detonation engine through conversion from an orthogonal coordinate system to a polar coordinate system. Therefore, a radial lateral expansion area source item is obtained; based on macro of a CFD solver, dynamic coupling calculation of radial and lateral expansion area source items and flow field parameters is achieved. According to the method, real-time coupling of the source item and the flow field can be achieved, the calculation precision and efficiency of the disc type rotary detonation engine are greatly improved, and therefore the iterative optimization speed of the geometric configuration of the disc type rotary detonation engine is increased.

The present disclosure relates to a method (200) for object detection in at least one blind spot (10) in the vicinity of a vehicle (20), wherein the method comprises acquiring (202) image data of an area in the vicinity of the vehicle (20) that at least partially covers the blind spot (10); processing (206) at least partially of the image data obtained in order to locate at least one object in the image data obtained; converting (208) at least partially of the processed image data into corresponding perimeter coordinates, wherein the corresponding perimeter coordinates are defined relative to a viewpoint from which the image data are obtained; and transforming (210) at least partially of the converted perimeter coordinates into corresponding orthogonal coordinates, wherein the corresponding orthogonal coordinates refer to an orthogonal viewpoint with respect to the blind spot (10).and the detection (212) of a movement of at least a part of the object relative to the blind spot (10) based on at least a part of the transformed orthogonal coordinates. The present disclosure also relates to a system (100) for object detection in a blind spot (10) in the vicinity of a vehicle (20).

The application discloses a method and device for secondary positioning of a seabed node based on quadrant division. 2 The method comprises the following steps: establishing an orthogonal coordinate system with the current position of the seabed node as a coordinate origin; positioning a target window in the orthogonal coordinate system with a set shot point offset distance as a limit; dividing the target window into n 2 quadrants based on the coordinate axes, wherein n is greater than or equal to 2; judging whether the difference amplitude of the dynamic corrected shot point data first arrival wave between the quadrants meets the error requirement; if not, determining the offset of the current position of the seabed node relative to the real position according to the difference amplitude, adjusting the current position, returning to the above step until the difference amplitude of the dynamic corrected shot point data first arrival wave between the quadrants is small enough, and determining that the current position of the seabed node is the real position. The method can verify the correctness of the node position in marine OBN exploration, and accurately position the node with a position deviation.

The application discloses a robot handheld sensor and a non-contact calibration method of sensor fixed installation, and belongs to the technical field of robots; the method comprises the following steps: S0, mounting a calibration block on a robot gripper and setting a laser displacement sensor on a tooling table; S1, respectively establishing a plurality of space orthogonal coordinate systems; S2, calculating the coordinates of a laser irradiation point of the laser displacement sensor on the calibration block; S3, judging whether the robot is collecting data for the first time, if yes, then offsetting and collecting data, and if not, then directly collecting data to obtain calibration data points; S4, calculating a homogeneous transformation matrix; and S5, calculating the coordinate values of the irradiation point and the space orthogonal coordinate system direction and the origin of the calibration block. The technical scheme has the advantages of automatic collection, higher precision, avoidance of the influence of manual teaching, small error and easy implementation.

The invention discloses a multi-vehicle collaborative navigation information screening and collaborative positioning method based on information geometry, and belongs to the field of navigation positioning. The method comprises the following steps: firstly, acquiring navigation source information and distance and direction finding information of a to-be-positioned vehicle and a cooperative vehicle, and converting the cooperative vehicle information into position estimation information of the to-be-positioned vehicle; then decomposing all positioning data along an orthogonal coordinate axis and establishing a unified probability distribution model; secondly, optimizing the data through a dual screening mechanism, wherein the dual screening mechanism comprises primary screening based on statistical characteristics, intermediate preferential selection based on error knowability and proximity, and secondary screening based on kernel density estimation; and finally, performing multi-source fusion on the screened data by using an information geometry theory, and adaptively correcting a distance measurement information variance through a feedback network to form closed-loop optimization. According to the invention, the precision, robustness and real-time performance of vehicle cooperative positioning in a complex environment are effectively improved.

The invention relates to an acceleration sensor having at least one piezoelectric element, at least one test mass, and a base body; the acceleration sensor is arranged in an orthogonal coordinate system having three axes, one of the three axes being a vertical axis; the base body has tangential sides and normal sides, the tangential sides being arranged tangentially with respect to the vertical axis, the normal sides being arranged normally with respect to the vertical axis; the acceleration sensor has exactly three piezoelectric elements and exactly three test masses; exactly one piezoelectric element is fastened on each of the three tangential sides; exactly one test mass is fastened on each of the three piezoelectric elements and exerts a shear force on the piezoelectric element that is proportional to the acceleration upon acceleration; each of the three piezoelectric elements has a high sensitivity to a shear force along a main tangential axis exerted by the test mass fastened thereto, the main tangential axis being a different one of the three axes for each of the three piezoelectric elements.