90results about How to "Avoid singularities" patented technology

The invention discloses a system for evaluating the disturbance rejection rate parasitical loop of a strap down infrared seeker. The system comprises a target simulator, a three-axis rotary table, the seeker and an emulation computer, wherein the target simulator simulates the movement relation of a target; the strap down infrared seeker detects the infrared signal source of the target simulator, and outputs a missile-target LOS (Line of Sight) rate obtained after decoupling filtering to the emulation computer, the emulation computer calculates the attitude and position information of a missile according to a practical kinetic model of the missile and transmits the attitude angle of a missile body to the three-axis rotary table to simulate the movement of the missile body; the emulation computer figures out a theoretical missile-target LOS rate and transmits the theoretical missile-target LOS rate to the target simulator to simulate the movement of the missile-target to form an entire closed-loop testing system. In the whole process, the emulation computer stores test data for final disturbance rejection rate calculation. The system eliminates the problem of singular point in the traditional disturbance rejection rate testing method, and enables that the disturbance rejection rate test is more accurate and a testing system is closer to the practical combat mode of the missile.

The invention discloses a robot control method capable of avoiding the generation of singular points, which comprises two stages of trial running and normal running of a robot, the executed concrete operation in the stage of trial running of the robot is as follows: the robot repeatedly runs, and portable singular points in a moving track of the robot are determined by check and calculation, and relevant data is stored in a preset database to be used for correcting the action in the normal running of the robot; and the operation in the stage of normal running of the robot is as follows: the results of check and calculation in the practical running process of the robot and the corresponding content in the database are compared to correct the practical running track of the robot to achieve the purpose of avoiding the generation of the singular points.

A three-transfer-one-shift four-degree-of-freedom heavy-load static-balance parallel motion simulation stand mechanism mainly comprises a basic platform, a motion platform, a load-bearing platform, four driving branches in identical structures and three balancing branches in identical structures. The four driving branches are connected with the motion platform and the basic platform to form a parallel driving mechanism. The three balancing branches are connected with the load-bearing platform and the basic platform to form a parallel balancing mechanism. The four driving branches are in uninterrupted power supply (UPS) structures and are composed of electric cylinders, first spherical hinges and universal hinges. The balancing branches are in RPS structures and are composed of balancing hydraulic cylinders or balancing air cylinders, first revolving pairs and second spherical hinges. The motion platform is connected with the load-bearing platform through a second revolving pair. The mechanism is high in bearing capacity, fast in dynamic response speed, simple to control, capable of preventing the three balancing branches from generating moments of rotation around a shaft and reducing the inertia force (moment) of a parallel load-bearing mechanism simultaneously and applicable to motion simulation of large devices, and the mechanism can be used indoors or in a field environment.

Disclosed is an attitude change control system that is designed to efficiently output a torque for attitude change of a space craft using CMGs and realizes a real time CMG driving rule. A CMG gimbal steering law 15 generates target profiles for setting angle and angular velocity for each gimbal by applying an anisotropic weighted gradient method based upon the necessary torque calculated by a feed back controller 13 and a feed forward controller 14 from the angle and angular velocity in the target direction from the attitude navigator 12 and the current angle and angular velocity of the space craft estimated by the attitude estimator 11 as well as the current condition of each gimbal from the CMG 40, thereby controlling the CMG 40 for changing the attitude of the space craft dynamics 50 to the target direction.

The invention relates to a redundant drive five degrees of freedom parallel machine tool with a large rotation angle. The redundant drive five degrees of freedom parallel machine tool with the large rotation angle includes a fixed platform, a movable platform for installing a main shaft head and a first driving branch, a second driving branch, a third driving branch and a fourth driving branch forconnecting the fixed platform and the movable platform, the structures of the first driving branch and the second driving branch are similar, and the first driving branch includes a hooke hinge, a servo driving unit, a revolute pair and a compound sphere hinge; the third driving branch includes a hooke hinge, a servo driving unit and a compound sphere hinge, the fourth driving branch includes a revolute pair, a servo driving unit, a hooke hinge and a revolute pair, and the movable platform of a machine tool and the four driving branches are hinged to form a space closed-cycle parallel mechanism; and the three-dimensional translation and the two-dimensional rotation of the space can be achieved by controlling six servo motors to drive the four branches. The redundant drive five degrees offreedom parallel machine tool with the large rotation angle has the advantages that the branch structures are simple and compact, the orientation workspace is large, the flexibility is high, the rigidity is large, and the singular configuration can be prevented, and can be used for high-speed, high-precision and efficiency machining for free-form surface in complex space.

The invention discloses a parallel serial embarkation mechanism motion planning method based on sea wave active compensation. According to the parallel serial embarkation mechanism motion planning method, the structure of a parallel serial embarkation system is analyzed and decomposed, thus a six-degree-of-freedom parallel platform and a three-degree-of-freedom serial gangway ladder kinematic module are established, motion quantity distribution is conducted on two subsystems through a jacobian matrix pseudo-inverse technique, present mission situation and constrained situation of the subsystems are combined, motion quantity of the system is optimized by using a gradient projection method, and the situation of singularity postures of the system is avoided. According to the parallel serial embarkation mechanism motion planning method, the kinematics multi-solution problem of degree-of-freedom redundancy of a parallel serial mechanism is effectively solved, meanwhile, factors such as joint spacing and the mechanism singularity postures are comprehensively considered, space motion distribution of the parallel serial mechanism is optimized to great extent, input parameters are providedfor control of the parallel serial embarkation system, and demands of operation and maintenance under actual working situation are met.

The invention discloses a three-degree-of-freedom plane parallel mechanism with novel redundant drive branched-chains, which belongs to the technical field of machinery manufacturing. The three-degree-of-freedom plane parallel mechanism comprises a quadrangular movable platform, three identical RRR branched-chains, an extendable branched-chain, an annular guide rail and a sliding block, wherein the movement of the three identical RRR branched-chains, the extendable branched-chain and the sliding block are driven and controlled through a servo motor; and the movable platform of the mechanism has three degrees of freedom, namely two translational degrees of freedom in a plane, and a rotational degree of freedom which is vertical to the plane. Due to the redundant drive branched-chains, the parallel mechanism is high in stiffness, and simultaneously, overcomes some singular configurations in an operational process, so that the working space of the mechanism is expanded. The redundant drive branched-chains of the mechanism can simultaneously control the size and orientation of tension and pressure applied to the movable platform, and can improve the accuracy of the movable platform in an operational process better through optimizing control.

The invention relates to a kind of redundantly driven active over-constraint three-degree-of-freedom parallel machine tool, which includes a moving platform 1, a fixed platform 2, and a first kinematic branch group 3, a second kinematic branch group 4, and a moving platform connected to the fixed platform. The third movement branch group 5, the fourth movement branch group 6, the structure of the first movement branch group and the second movement branch group are exactly the same, and the servo drive unit connects the branch body and the Hooke hinge through the rotating pair Connected with the moving platform, the third motion branch chain group is connected to the branch chain body through the Hooke hinge by the servo motor unit and connected to the moving platform through the Hooke hinge, and the fourth motion branch chain group is connected to the branch chain body by the servo drive unit through the Hooke hinge And the Hooke hinge or compound spherical hinge is connected with the moving platform. The invention synthesizes a three-degree-of-freedom parallel machine tool with two rotations and one movement, which has the advantages of simple branch chain, symmetrical structure, high degree of recombination and modularization, strong load capacity, excellent comprehensive performance, large working space, and avoidance of singular configurations, etc. It has good engineering practical application prospects.

A multi-degree-of-freedom electromagnetic machine that may be operated as a motor, a generator, or a motor-generator, includes a first structure and a second structure. The first structure comprises a first conductor, a second conductor, and a third conductor, each of which follows a different trajectory. The first, second, and third conductors together form a general shape of a surface. The second structure is disposed adjacent to the first structure and includes a magnet that emanates a magnetic field. The magnet has at least one of its magnetic poles facing the surface. A Lorentz force affects relative movement between the first structure and the second structure when the magnetic field that emanates from the at least one magnetic pole interacts with electrical currents within any of the electrical conductors.

The invention provides a time varying division method applied to stabilization of a swinging angle of a hanging load of a helicopter. The method includes the following steps: 1), giving a dynamical equation of a helicopter hanging simplified model, and acquiring relevant parameters; 2) establishing a mathematic model for stabilization control of the swinging angle of the hanging load of the helicopter based on the dynamical equation of the step 1, and providing a time varying division question; and 3) designing a solver and performing real-time solution to the time varying division question of the step 2. According to the time varying division method applied to stabilization of the swinging angle of the hanging load of the helicopter, the solver is simple, and the problem of that the conventional static division method occurs an abnormal state during a divide-by-zero situation can be avoided.

The invention discloses a geosynchronous orbit determination and parameter determination method based on differential algebra. A kinetic model described based on geosynchronous satellite orbit elements is selected and used, use of a relatively greater integration step in a numerical integration process is avoided and appearance of singular points is avoided for the kinetic model, moreover, a perturbative force item is added in the kinetic model, polynomial form integration is executed, thus, obit statuses and spacecraft parameters are obtained, high-order prediction is executed for the obtained parameters, and meanwhile, high-order prediction of observed quantity is executed; by means of nonlinear information of the kinetic model and an observation model, estimation accuracy is improved; in combination with actual observed values of a spacecraft, high-order prediction values of the obit status and the spacecraft parameters are updated and high-order estimated values as initial values are obtained; and by repeating the implementation process above, geosynchronous orbit determination and parameter determination can be completed. The method provided by the invention not only can improve accuracy of obit estimation and realize high-precision estimation of the parameters, but also can greatly reduce calculation cost.

The invention discloses a motion redundancy face shovel excavating mechanism capable of optimizing lifting force, wherein a movable arm is hinged with a frame; a hopper rod is hinged with the movable arm; a bucket is hinged with the hopper rod; the frame, the movable arm, the hopper rod and the bucket form an open type tandem connection chain; a powerful triangle is hinged with the movable arm, the end part of the cylinder sleeve of the bucket hydraulic cylinder is hinged with the bucket, and the end part of the piston rod of the bucket hydraulic cylinder is hinged with the powerful triangle; the end part of the cylinder sleeve of the hopper rod hydraulic cylinder is hinged with the hopper rod, and the end part of the piston rod of the hopper rod hydraulic cylinder is hinged with the movable arm; the end part of the cylinder sleeve of a driving arm hydraulic cylinder is hinged with the powerful triangle, and the end part of the piston rod of a main driving arm hydraulic cylinder is hinged with the frame; and the end part of the cylinder sleeve of an auxiliary driving arm hydraulic cylinder is hinged with the powerful triangle, and the end part of the piston rod of the auxiliary driving arm hydraulic cylinder is hinged with the frame. The motion redundancy face shovel excavating mechanism provided by the invention has the characteristics of motion redundancy, large driving force arm, excellent flexibility and optimized input force.

Methods and a steering device for minimally invasive visualization surgery system are disclosed. In particular, the steering device configured for holding and positioning an image capturing device about a frame above a surgical site. The steering device including a curvilinear prismatic joint which may be operated by an end effector and a braking system including one or more sensors. In some embodiments, one or more electrical power mechanisms can be used to inhibit motion according to predetermined parameters can be included. A controller in logical communication with a database including said predetermined parameters (including, for example, ranges of motion for the curvilinear prismatic joint) may also be used to control the range of motion using the one or more electrical power mechanisms and/or the braking system. The braking system can include one or more of a frictional brake, a pumping brake, and an electromagnetic brake.

The invention discloses a redundant drive symmetric three degree-of-freedom mobile parallel mechanism, which mainly comprises four fixed guide rails, a moving platform and four branched chains with the identical structure and for connecting the moving platform and the fixed guide rails, wherein the four fixed guide rails are uniformly distributed on the same conical surface, one ends of upper connecting rods of the branched chains are connected with the moving platform through revolute pairs, the other ends of the upper connecting rods are connected with one ends of lower connecting rods through sliding pairs, the other ends of the lower connecting rods are connected with the fixed guide rails through cylindrical pairs, the mobile parts of the cylindrical pairs are input kinematic pairs, the axial lines of the cylindrical pairs coincide with the axial directions of the fixed guide rails, the four revolute pairs on the four branched chains are uniformly distributed on the moving platform, the axial lines of the revolute pairs are parallel to the axial lines of the cylindrical pairs, and the axial lines of the sliding pairs are perpendicular to the axial lines of the cylindrical pairs. The mechanism has the advantages of large bearing capacity and excellent isotropy.

The invention relates to a human body joint angle resolving method and device based on quaternion numbers. The method comprises the following steps of obtaining initial quaternion numbers at a first collecting point and initial quaternion numbers at a second collecting point; calculating initial bias quaternion numbers of the initial quaternion numbers at the first and second collecting points by using the initial quaternion numbers at the first collecting point and the initial quaternion numbers at the second collecting point; obtaining current quaternion numbers at the first collecting point and current quaternion numbers at the second collecting point in each collecting period; calculating an absolute bias quaternion numbers of the current quaternion numbers at the first and second collecting points by using the current quaternion numbers at the second collecting point and the current quaternion numbers at the second collecting point; calculating relative bias quaternion numbers of the first collecting point and the second collecting point at the current moment; resolving the relative rotating angle of the right arm elbow joint in the three-axis direction according to the relative bias quaternion numbers. The device is realized on the basis of the method. The robot following control based on the human body posture can be realized by using the real-time angle change of the quaternion numbers of the two collecting points resolved in the three-axis direction of the human body joint relative to the initial position.

The invention relates to an alternating current electromagnetic positioning device and an alternating current electromagnetic positioning method, and belongs to an electromagnetic positioning device and an electromagnetic positioning method. The alternating current electromagnetic positioning device comprises a data processing and time sequence control unit, a D/A (digital to analog) converting circuit, a sending driving circuit, an overvoltage protection circuit, a three-axis emitting source, a receiving antenna, a multipath selecting circuit, a filter amplifying circuit and an A/D (analog to digital) converting circuit. According to the method, firstly, the data processing and time sequence control unit controls the D/A converting circuit to generate sinusoidal signals with different frequencies, the sinusoidal signals are sent to the three-axis emitting source after being subjected to amplitude and power amplification, the receiving antenna receives electromagnetic signals of space radiation, and the position posture information of a target is solved by a solving algorithm and is transmitted to an upper computer for display. The alternating current electromagnetic positioning device and the alternating current electromagnetic positioning method have the advantages that a hardware processing circuit is simplified, the problems of complicated circuit and low positioning speed caused by the existing time-division system work mode are avoided, the positioning timeliness is ensured, and in addition, the singular point problem of the positioning is solved.

A motion redundancy face shovel excavating mechanism containing a lengthened arm comprises a tandem connection mechanism formed by a frame, a movable arm, a lengthened arm, a hopper rod and a bucket which are sequentially hinged, and four pairs of driving hydraulic cylinders are fully and symmetrically arranged on the two sides of the tandem connection mechanism. The frame is hinged with the lower end of the movable arm, the upper end of the movable arm is hinged with one end of the lengthened arm, the other end of the lengthened arm is hinged with one end of the hopper rod, and the other end of the hopper rod is hinged with one part of a bucket; another part of the bucket is hinged with one end of each of the pair of bucket hydraulic cylinders, and the other end of the pair of the bucket hydraulic cylinders is hinged with the middle of the lengthened arm; the middle of the movable arm is hinged with one end of the pair of movable arm hydraulic cylinder, and the other end of the pair of movable arm hydraulic cylinder is hinged with the frame; the hopper rod is hinged with one end of the hopper rod hydraulic cylinder, and the other end of the hopper hoper hydraulic cylinder is hinged with the frame; and a pair of hydraulic cylinders for driving motion redundancy can adopt various connection ways. The motion redundancy face shovel excavating mechanism containing the lengthened arm has the characteristics of motion redundancy, large driving force arm and large space, and can achieve heavy load excavation.

The invention provides a face shovel spadework device provided with movement redundancy and capable of optimizing spading force. The lower end of a movable arm is hinged with a rack; the upper end of the movable arm is hinged with one end of a bucket rod, the other end of the bucket rod is hinged with one part of a bucket, and the components are respectively connected by bucket hydraulic cylinders, movable arm hydraulic cylinders, two pairs of bucket rod hydraulic cylinders and power trigones by virtue of four connection modes. The device provided by the invention has the characteristics of realizing movement redundancy, avoiding configuration singularity, optimizing the spading force and realizing large-tonnage heavy-load excavation.

The invention discloses a configuration-variable quadruped robot motion control method and system. The method comprises the following steps that: the gait of a quadruped robot is planned; an integer programming model of the quadruped robot is established by taking the current joint position and speed of the robot as input based on differential kinematics of the robot; based on the redundant degreeof freedom, switching among various configurations of the robot is achieved; and the movement of the robot is planned based on a current configuration, and the expected foot end positions of a supporting phase and a swinging phase are planned. Therefore, all-directional movement of the quadruped robot under multiple configurations is achieved, and stability and adaptability are remarkably improved when the quadruped robot confronts complex terrains.

The invention belongs to the field of robots, and particularly relates to a space decoupling parallel and serial mechanism. The space decoupling parallel and serial mechanism mainly comprises a parallel mechanism (2T1R) and a sliding pair 1T, wherein the sliding pair 1T is serially connected to a movable platform of the parallel mechanism; the parallel mechanism consists of a fixed platform, the movable platform and three branches; the fixed platform is connected with the movable platform via the three branches; each of the first branch and the second branch consists of a cylindrical pair, a parallelogram hinge, two revolute pairs with parallel axes, a revolute pair of which an axis is perpendicular to the movable platform and four connecting rods; the cylindrical pair, the parallelogram hinge, the two revolute pairs with the parallel axes and the revolute pair of each of the first branch and the second branch are connected to one another by the corresponding four connecting rods; the third branch consists of a revolute pair parallel to the fixed platform, three revolute pairs with parallel axes and three connecting rods; the revolute pair parallel to the fixed platform and the three revolute pairs with the parallel axes are connected to one another by the three connecting rods; and the tail end of the mechanism is connected with the movable platform through the sliding pair of the movable platform. The space decoupling parallel and serial mechanism is stable in structure, three-degree-of-movement and rotation around the axis of the revolute pair, which is connected with the fixed platform, in the third branch can be implemented, different movements are decoupled and are easy to control, the motion space is large, and the bearing capacity is high.