192 results about "Kinematic chain" patented technology

The invention relates to the technical field of robot anomaly prediction, in particular to a robot anomaly prediction method and system based on multi-dimensional fusion and causal inference. The method comprises the steps of performing multi-scale depth state characterization based on acquired robot multi-joint sensing data, and performing dynamic causal graph fusion based on the multi-scale depth state characterization. Comprising the steps of priori knowledge graph construction based on a kinematics chain, dynamic association attention mechanism construction based on data driving, state fusion of knowledge and attention guidance and global state vector generation. Performing hierarchical space-time dependency prediction based on the fused features, wherein the hierarchical space-time dependency prediction comprises robot joint topological graph construction, spatial dependency dynamic modeling, long-range time evolution prediction and future robot health state prediction; the method shows excellent performance in a plurality of core dimensions such as prediction precision, early warning timeliness and diagnosis interpretability, and has extremely high actual deployment value and engineering popularization potential.

The invention discloses a charging robot automobile charging port pose vision measurement method comprising the following steps: 1, controlling a mechanical arm to drive a monocular camera to collect a charging port image, and constructing a charging port image data set; 2, extracting a charging hole contour in each image by adopting an improved Mask R-CNN instance segmentation model; step 3, performing robust ellipse fitting based on each charging hole contour to obtain center coordinates of each charging hole in the two-dimensional image; step 4, establishing a world coordinate system based on charging hole space distribution defined by the automobile charging port standard model, and determining three-dimensional coordinates of each charging hole; and 5, the multi-view two-dimensional center coordinates and the corresponding three-dimensional coordinates are input into the PnP graph optimization model, and the pose of the charging port in the mechanical arm base coordinate system is solved by fusing the re-projection error constraint, the structure prior constraint and the kinematics chain constraint. The invention further discloses a charging robot automobile charging port pose vision measurement charging method and a charging system.

The invention discloses a precision compensation method of a composite numerical control machine tool, and particularly relates to the technical field of precision control of the numerical control machine tool, which comprises the following steps: synchronously acquiring temperature, vibration and force information under the driving of a unified clock through multiple types of sensors deployed at key nodes of the machine tool, and generating a synchronous multi-source sensing data set with aligned timestamps; inputting the data set into a multivariable coupling error model obtained through data driving training, and calculating and generating a comprehensive space volume error predicted value of a tool nose point of the tool; performing inverse calculation based on a machine tool kinematic chain model, and generating a multi-dimensional micro-compensation instruction set containing the compensation amount of each motion axis and the sequential relationship; and finally, dynamically writing the instruction set into a servo control ring of the numerical control system through a real-time data interface, and driving each motion shaft to execute synchronous compensation motion. According to the method, comprehensive compensation of multi-physics field coupling errors such as temperature, vibration and force load is achieved, and the machining precision and stability of the numerical control machine tool under complex working conditions are improved.

The invention discloses a knee joint postoperative rehabilitation management system, which comprises the steps of building a hip-knee-ankle multi-joint associated diagnosis AI model, generating an evaluation result based on the hip-knee-ankle multi-joint associated diagnosis AI model, generating a staged rehabilitation scheme through reinforcement learning and a rehabilitation knowledge graph, and performing rehabilitation management on the rehabilitation scheme. Sensor data in the training process of a patient is collected through a detection suite and input into an action judgment model after being preprocessed, and the model outputs an action correctness score and an error type in combination with a shank-thigh axis consistency judgment algorithm and an action standard library; according to the action correctness score and the error type, the patient is guided to adjust the action, and rehabilitation training closed-loop management is achieved. The knee joint compensation relation can be accurately judged, the kinematic chain balance principle of knee rehabilitation training can be met, the correctness of actions during training can be accurately judged, and joint unbalance is avoided.

The invention provides a self-supervised continuous 3D hand posture tracking method based on a lightweight inertial measurement unit, and the method specifically comprises the following steps: firstly, obtaining a hand motion signal by using a lightweight consumer-level IMU, and extracting features by using a multi-stage neural network containing a bidirectional long-short term memory (Bi-LSTM) module; the global displacement and orientation of the hand are processed through a wrist posture estimation module, and three-dimensional coordinates of hand skeleton points are solved and calculated by means of a finger motion chain; secondly, a self-supervised completion network is realized by combining a random mask and dual loss, and the features are processed to complete complete attitude reconstruction; and finally, combining network output with kinematics prior, generating a three-dimensional grid with reasonable anatomy, solving the problem that joint deformation is inconsistent with torque, and realizing accurate acquisition of a three-dimensional hand posture. For a dynamic hand motion tracking task, the method can adapt to a sparse IMU deployment scene and realize continuous high-precision tracking; the real-time performance demand of daily interaction can be met, and a low-cost solution can be provided for the fields such as medical rehabilitation and virtual interaction which have strict requirements on attitude precision.

The invention relates to the technical field of rehabilitation medical treatment, and discloses a muscle group stress analysis method and device, a terminal and a storage medium, and the method comprises the steps: respectively obtaining motion data collected by inertial measurement units arranged on the body of a user, and recognizing gait events based on the motion data corresponding to the inertial measurement units of the lower limbs, dividing the continuous motion data into a plurality of gait cycles according to the gait event; fusing the motion data acquired by each inertial measurement unit to obtain a three-dimensional posture of each preset segment of the body, and constructing a three-dimensional motion track of the spine area of the user in combination with a human kinematics chain model; processing the three-dimensional motion track and the known muscle group stress data by adopting a singular value decomposition embedding regression method to obtain a preliminary target muscle group stress curve of each gait cycle; and correcting the initial target muscle group stress curve based on a human body multi-rigid-body dynamic model in combination with a control cost function to obtain a final target muscle group stress curve.

The invention provides a double-layer intelligent agent optimization method, device and equipment for multiple mechanical arms and a storage medium. An RRT-Connect algorithm and B spline track smooth optimization are introduced into a high layer, and global path planning is conducted on environment information of a carrying task; the smoothed centroid trajectory is converted into a reference trajectory sequence at the tail end of each mechanical arm by using a kinematics chain model, then the reference trajectory is used as a bottom layer distributed real-time control guide signal driven by an MAPPO algorithm, and comprehensive feedback is performed on task completion degree, motion smoothness and coordination in combination with a multi-layer reward function; and all the mechanical arm intelligent bodies are guided to cooperatively adjust joint actions in the tracking process, so that seamless connection of global planning and local control is achieved, and the smoothness and cooperative efficiency of carrying motion are remarkably improved.

The invention relates to a multi-stage optimization and kinematics constraint-based thumb posture estimation method and computing equipment. The method comprises the following steps of: acquiring original hand data, preprocessing the original hand data, and initializing parameters; constructing a multi-objective optimization function with multiple constraints, obtaining an initial estimation thumb posture based on the preprocessed data, taking the initial estimation thumb posture as an initial value, and performing recursive calculation by using a kinematics chain to obtain an accurate angle of each joint of the thumb; integrating the accurate thumb joint angle to complete hand posture parameters and outputting the parameters; a computing device is implemented based on the method. Complete and accurate thumb kinematic chain recovery under incomplete input is achieved, it is guaranteed that all estimated thumb joint angles conform to the human anatomy activity range, and high-fidelity basic data are provided for downstream application; the generated thumb motion sequence is continuous and smooth in the time dimension, and the visual experience in real-time interaction application is greatly improved; in an interactive application, a more natural, accurate and jitter-free gesture control experience can be realized.

The invention relates to a biped robot gait planning method. The invention relates to the technical field of robot gait planning, and the method comprises the steps: taking a kinetic model of a robot as input, so as to achieve the neural network reasoning of simulation; describing the robot by using a URDF file, and enabling the robot to be equivalent to a kinematic chain formed by connecting rigid bodies in series; through accurate description, a robot consistent with that in reality is established in a simulation environment, the robot is enabled to carry out gait learning in a simulation physical environment, and supervised random divergence trial and error are carried out in a mode of setting initial conditions, termination conditions and reward and punishment conditions so as to realize gait learning. According to the invention, through repeated modification of parameters and structural adjustment of adaptability, a stable, low-energy-consumption and high-robustness control strategy is finally obtained through training.

Systems and methods for assisting movement of a user and / or a base connected to one or more robotic limbs are described herein. Forces may be applied to one or more robotic limbs to control movement of the base. The base may be attached to a user, or other payload, and forces applied to the base due to externally applied forces, such as those applied by a user interacting with an environment, may result in reactionary forces being applied to the one or more robotic limbs. These forces may be detected and used to determine one or more commands for operation of the one or more robotic limbs. Optionally, the robotic limbs may include one or more end effectors which may removably couple or otherwise be held substantially stationary relative to an environment to form a closed loop kinematic chain.

The application relates to the technical field of four-degree-of-freedom parallel mechanisms, in particular to a three-branch-chain space four-degree-of-freedom parallel mechanism which comprises a static platform, a mixed branch chain, a simple branch chain one, a simple branch chain two and a dynamic platform; the application has a mixed branch chain of a space sub-branch chain type and two simple branch chains, forms a basic motion chain containing three loops, thereby realizing the advantages of good rigidity and high precision, the displacement of the dynamic platform in the X-axis and Y-axis directions is controlled by two moving pairs respectively, the displacement in the Z-axis direction and the rotation around the Z-axis direction are controlled by four moving pairs, therefore, the application has good partial motion decoupling, the symbolic position direct solution is easy to obtain, thereby facilitating the motion control, trajectory planning and dynamics analysis of the parallel mechanism, and the three-dimensional position working space of the dynamic platform is large, the rotation capacity is strong, and the branch chains are not prone to interference.

The invention discloses a method and system for rapidly defining motion coordinates in a numerical control multi-axis machine tool simulation system, and belongs to the technical field of numerical control machining. According to the method, all moving parts of a machine tool are organized into a tree-shaped topological structure according to a kinematic chain relation; automatically generating a local coordinate system for each moving part; calculating a cumulative transformation matrix through matrix cumulative multiplication; receiving a graphical dragging operation of a user on the moving part; according to the position of the moving part in the topological structure tree, identifying the allowable motion freedom degree type of the moving part, and projecting the dragging vector to a corresponding motion axis; calculating a motion increment and updating a position parameter; recalculating the coordinate transformation matrix to realize real-time simulation display, and converting the motion sequence into a numerical control code; according to the method, a user can explore and define the motion trail from zero through interactive operation, the period from design conception to verification simulation is greatly shortened, and the development efficiency of numerical control machining is improved.

The invention relates to the technical field of non-standard automation equipment control, in particular to an industrial robot machining program migration method based on a configuration description file, and solves the problem that a non-standard industrial robot cannot migrate a machining program. The method comprises the steps that S1, a configuration description file of a prototype industrial robot is constructed, and based on object-oriented abstract modeling, kinematics, peripheral and communication modeling and a machining program are included; s2, the target robot is assembled according to the prototype physical structure, and it is ensured that the same configuration, component assembly, the axis movement direction and the origin coordinate are consistent; s3, loading the configuration file to the target robot; s4, correcting assembly errors through visual sensing, obtaining accurate coordinates among the parts, and then generating joint coordinates through inverse solution; and S5, the target robot executes the adaptive machining program, and program migration is achieved. According to the method, prototype machine information is packaged through the configuration description file, after the target machine is loaded, errors are corrected only through visual calibration, rapid adaptive machining can be achieved through kinematic chain inverse solution, and rapid copying of robots of the same configuration is achieved.

The invention relates to a Tripteron-type parallel manipulator configured to provide three purely translational degrees of freedom by means of three orthogonal linear actuators and their respective parallelogram-shaped kinematic chains. The system incorporates an auxiliary active support arranged on the Z-axis, intended to apply an upward vertical force to the moving platform (11) in order to reduce the load borne by the kinematic chain and the main Z-axis actuator. This support can be implemented using electric or pneumatic actuators, elastic elements, or cable-driven mechanisms, allowing for active, passive, or semi-active operating modes.The integration of the auxiliary support increases the manipulator's load capacity, improves its dynamic stability, and reduces the mechanical demands on the vertical actuator, while maintaining the purely translational kinematics and structural characteristics of the original Tripteron unchanged.

This invention relates to a trenching device and method for pipeline laying. The trenching device includes a connecting frame, a support frame, a chain drive mechanism, strip plates, a shearing plate, and a reciprocating motion mechanism. The support frame is located below the rear side of the connecting frame. The chain drive mechanism is mounted on the support frame and can drive the chain to move back and forth circumferentially. A strip plate extending laterally is fixed to a link of the chain. The strip plate has left and right extending grooves, with the groove openings facing away from the corresponding chain link. The shearing plate is slidably connected within the grooves. Both the shearing plate and the strip plate have shearing portions at their edges near the groove openings. The reciprocating motion mechanism is mounted on the strip plate and is connected to both the shearing plate and the drive mechanism. The chain drives the reciprocating motion mechanism on the strip plate to move back and forth circumferentially, and the reciprocating motion mechanism, driven by the drive mechanism, drives the shearing plate to reciprocate left and right. This invention ensures continuous and efficient trenching operations.

The invention relates to the field of ankle joint rehabilitation robots, in particular to a one-translation and two-rotation type parallel ankle joint rehabilitation robot and a working method. The parallel mechanism comprises a static platform, a first mixed branch chain, a second just constraint branch chain and a movable platform, and a basic kinematic chain containing two loops is formed. The mechanism only comprises a translation pair and a rotation pair, so that the mechanism has the advantages of high rigidity and good precision.

The invention discloses a motion analysis and feedback method and device and a computer readable storage medium, and the method comprises the steps: building a neutral position reference model based on the skeleton features of a user, and calculating the instantaneous deviation features of a real-time posture and the reference model; resolving a time domain accumulation feature representing the stubborn degree of the action error and a time domain change rate feature representing the deterioration trend of the action error in real time; retrieving the kinematic chain knowledge graph to obtain attribution information; inputting the features into an adaptive feedback control model, dynamically calculating abstract hierarchy parameters of a teaching strategy based on the magnitude of time domain accumulation features, respectively calculating mood specificity parameters and intervention opportunity parameters in combination with instantaneous deviation features and time domain change rate features, and generating prompt control parameters; and finally, system prompts are assembled based on the prompt control parameters, and self-adaptive feedback information is generated. According to the application, the crossing from mechanical error correction to adaptive closed-loop teaching can be realized.

This invention proposes a comprehensive compensation method for key errors in five-axis in-machine measurement. This method compensates for pre-travel errors along the normal vector in the machine tool coordinate system during five-axis in-machine measurement, avoiding the inaccuracy of compensation along the normal vector in the part coordinate system in existing technologies. Furthermore, a high-precision and stable laser interferometer is used to identify the positioning deviations of the two rotation axes, and the identified deviations are substituted into the machine tool kinematics chain to offset the rotational angle positioning deviations introduced in the five-axis in-machine measurement. The calculation method of this invention is simple and reliable, and can be extended to in-machine measurement on four-axis machine tools or other five-axis machine tools with different structures.

The application discloses a hand exoskeleton for capturing finger movement and a finger configuration reconstruction method, and can realize full-space precise movement capturing of human fingers and reconstruction of finger configurations. The hand exoskeleton is composed of a plurality of serial kinematic chains and a common base, each serial kinematic chain comprises one active joint and five passive joints, and a magnetic rotation angle sensor is arranged on the joint to realize movement capturing of the end of the serial kinematic chain. The serial kinematic chain forms a parallel structure with a human finger to realize six-degree-of-freedom precise movement capturing of the end of the human finger. Captured human finger tip movement is reconstructed through a circular arc fitting algorithm, and the finger movement configuration can be displayed in real time in a three-dimensional visual simulation environment. According to different requirements, the number of serial kinematic chains on the base can be increased or reduced, and hand movement can be reproduced in real time in a three-dimensional simulation environment, and experience is improved.

An aircraft rudder pedal includes a frame, a pair of pedals, an output shaft and a mechanical kinematic chain for transmitting to the output shaft a displacement of at least one of the pedals relative to the frame. The mechanical kinematic chain comprises a central transmission part able to be rotated relative to the frame by a displacement of one of the pedals relative to the frame. The mechanical kinematic chain also includes a transmission mechanism joining the central transmission part to the output shaft. The transmission mechanism includes a homokinetic association of two universal joints between said central transmission part and the output shaft.

The application discloses a Tai Chi action posture recognition and deviation correction training system and relates to the technical field of action recognition and sports training, and solves the technical problems that it is difficult to quantitatively recognize the coherence of Tai Chi actions, the guidance lags behind the actions, and the template does not match the body shape of a user. The system comprises a posture acquisition module, which acquires a user bone frame sequence and a joint angular velocity change rate; a motion trend prediction module, which adopts a rotation matrix to predict the head and a forward kinematics chain to recursively output a next frame prediction coordinate; a ghost generation module, which sets a differential matching window according to four stages of Tai Chi, generates a semi-transparent ghost by performing size normalization mapping on a three-bone segment group scale factor weighted by square roots of joint numbers, and performs size normalization mapping on a three-bone segment group scale factor weighted by square roots of joint numbers; a deviation perception module, which constructs a dynamic weight smoothness penalty term to generate a deviation correction signal; and a multi-modal feedback execution module, which maps a deviation amount into a line color and a vibration parameter, and outputs feedback according to the time sequence of vision, touch and voice.

The invention provides a sub-closed-loop-containing robot kinematics calibration method and device based on constraint relaxation, and relates to the technical field of robot calibration, and the method comprises the steps: carrying out the decomposition of a main kinematic chain under the condition that there are multiple branches in the main kinematic chain of a robot, so as to generate multiple virtual kinematic chains; according to kinematic parameters and closed-loop geometric constraints of virtual joints in each virtual kinematic chain, the theoretical tail end pose of the robot is determined; parameter errors are determined according to the pose deviation between the theoretical tail end pose and the actual tail end pose of the robot; according to the parameter errors and the calibrated kinematics parameters, the corrected pose deviation is determined; and the active joint displacement is updated according to the corrected pose deviation until the corrected pose deviation or the active joint displacement meets the iteration termination condition, the robot is calibrated according to the determined active joint target displacement, and the calibration precision of the robot is improved.

The invention discloses a mold opening and closing stroke control method of an electric injection molding machine, which comprises the following steps: S1, acquiring key geometric parameters of a toggle rod system in a five-hinge-point inclined double-toggle mold closing mechanism, and adjusting main variable conditions of a mechanism kinematic chain based on theoretical formulas of a movable mold plate stroke (Sm) and a ball screw driving stroke (So), data association points between the driving stroke of the ball screw and the stroke of the movable template are obtained; s2, constructing a function mapping model between a moving template stroke (Sm) and a ball screw driving stroke (So) according to the data obtained in the step S1, and forming a fitting expression in a form of Sm = f (So); and S3, establishing a reverse fitting function, and forming function mapping of So = (Sm). Reverse control is realized by precisely fitting the relationship between the template and the stroke of the ball screw, so that errors caused by using an interpolation method are reduced, the system control precision in the mold opening and closing process is improved, the calculation efficiency is greatly improved, the storage space is saved, and the cost is further reduced.

The invention relates to the technical field of mobile surveying and mapping and wearable computing, and discloses a head-mounted laser radar point cloud matching method and device, and the method comprises the steps: receiving an original laser point cloud data stream and inertial measurement data; human cervical vertebra kinematics chain parameters are read; establishing a continuous time trajectory model by using an accumulated B-spline function; inversely solving a human cervical vertebra joint configuration vector according to the current track state; calculating an analytic geometry jacobian matrix; constructing a manifold tangent space projection operator by using an analytic geometry jacobian matrix; and executing joint constraint optimization based on tangent space projection, constructing a joint constraint Jacobian matrix by using a manifold tangent space projection operator, solving an incremental equation, and carrying out iterative updating on a B spline control point. According to the method, trajectory update is strictly limited in the human cervical vertebra kinematics manifold by using the manifold tangent space projection operator, motion noise violating a physiological structure is effectively filtered, and the physical consistency and precision of pose calculation in a complex motion scene are improved.

The application discloses a numerical control machine tool control method and system for complex curved surface machining, and relates to the field of numerical control machine tool control. The method comprises the following steps: extracting an original G code instruction stream, reconstructing ideal position instruction sequences and ideal speed instruction sequences of each motion shaft according to a machine tool kinematic chain model; estimating instruction phase lag amounts of each motion shaft through an inter-shaft phase lag predictor; combining geometric curvatures and tangent directions of a machining path, calculating estimated profile error vectors through a profile error coupling mapping model; combining profile accuracy requirement constraints of a surface to be machined and a shaft contribution weight matrix, and constructing a compensation optimization model; and fusing inter-shaft phase compensation instructions and the original G code instruction stream in a numerical control machining program according to a solution of the compensation optimization model, generating a synchronized instruction stream, and driving each shaft of the machine tool to move. The method solves the problems of poor synchronization of multi-shaft cooperative movement, low estimation accuracy, and low adaptability of instructions to mechanical structure characteristics of the machine tool.

The invention discloses a three-dimensional visualization method of a five-degree-of-freedom hybrid robot, and relates to the field of robot technology visualization, and the method comprises the following steps: obtaining real-time joint data collected by position sensors deployed at all active joints of the robot; performing forward kinematics calculation on the real-time joint data to obtain tail end pose data of the robot; inverse kinematics calculation is carried out on the tail end pose data, and theoretical pose data describing the spatial positions and postures of all parts of the robot are obtained; a three-dimensional surface model file of the robot is obtained and analyzed, and initial geometric data of all parts are extracted; according to the method, closed-loop kinematic chain constraint resolving of the hybrid mechanism is achieved through kinematics of the five-degree-of-freedom hybrid robot, and it is ensured that the poses of all the parts are accurately described.

The invention discloses a milling system and a using method, belongs to the field of civil engineering, and particularly relates to the field of wall surface grooving of the civil engineering. Comprising a zipper device, a milling device, a chain and a power source, the zipper device comprises a zipper support and a zipper driving mechanism, and the zipper driving mechanism is installed on the zipper support. The chain driving mechanism is driven by a power source, and the screw-in end of the chain stretching edge is connected with the chain driving mechanism; the chain stretching edge is consistent with the working direction; the screw-out end of the chain stretching edge is connected with the milling device in a matching manner; the chain drives the milling device to generate milling motion; the pulling force of the chain drives the milling device to generate feeding motion close to the zipper device. The wall groove capable of containing the threading pipe is constructed in the side wall of the foundation wall groove, the opening is narrower than that in the prior art, and the problems of surface defects of the facing layer, bulging and loosening of filler and collapse of the threading pipe are solved.

The utility model relates to the technical field of polishing equipment, in particular to polishing equipment for cutter machining. Supporting legs are fixedly connected to the bottom of the bottom plate, a side plate is fixedly connected to the top of the bottom plate, a control device is fixedly connected to the exterior of the side plate, and a top plate is fixedly connected to the back of the bottom plate; the first motor drives the rotating plate to rotate, so that the rotating plate enters the intermittent plate and pushes the intermittent plate to rotate, and then the rotating plate retreats. The action enables the intermittent plate to intermittently rotate to drive the chain on the first chain wheel to move on the second chain wheel. A stop clearance exists when the chain moves, and at the moment, a to-be-polished cutter is manually placed on the inner side of the protection plate. The second motor drives the screw to rotate and drives the sliding plate to slide along the sliding rod, so that the L-shaped rotating plate rotates around the fixing frame and pushes the clamping block to clamp the tool, meanwhile, a worker on the other side takes down the polished tool, the continuous production process is formed, the production efficiency is improved, and operation safety is guaranteed.

The application provides a UAV radar cover lateral folding connection mechanism, comprising a hinge base assembly, an upper hinge assembly, a lower hinge assembly, a plurality of hinge shaft assemblies, a fuselage front frame, a radar cover ring frame assembly, a radar cover, a plurality of positioning pin seats and a limiting assembly. The application realizes the connection between the radar cover and the fuselage through two synchronous open motion chains, and the radar cover can be quickly and smoothly opened and closed laterally. The technical scheme of the application can solve the technical problems of the prior art, such as complex opening and closing operation process, long dismounting time and sealing scheme limited by the motion track of the radar cover.

The present invention discloses a lockable three-dimensional rotation metamorphic parallel mechanism based on a coupling chain, wherein a plurality of platforms are arranged in sequence and spaced apart; a kinematic chain is connected in parallel between two adjacent platforms, constraining the three-dimensional rotation of one of the two adjacent platforms relative to the other; each kinematic chain parallel unit includes a plurality of kinematic chains, each of which includes a first branch and a second branch, the plurality of first branches are connected in parallel to two adjacent platforms, and the plurality of second branches are connected in sequence between two adjacent first branches; in the same kinematic chain parallel unit, when each kinematic chain has a singular position, the second branch can use its own local degree of freedom to lock and unlock the first branch. The present invention can solve the high load-bearing problem of the locking mechanism, while avoiding the displacement fluctuation of the energy-type multistable structure under impact load and the unidirectional load-bearing problem of the contact metamorphic.