97 results about "Leader follower" patented technology

The present invention provides a system and apparatus for efficient and reliable, control and distribution of data files in large-scale distributed networks. The members of a group of servers in a multicast network elect a group leader whenever a new group leader is required, as when the prior group leader become unavailable, as detected by absence of a periodic heartbeat message published by the leader. The election is carried out by a system of voting by each candidate whereby each candidate has a priority calculated from its configuration, and the server with the highest priority is configured to claim the leadership faster than the other candidates. As part of the claim, each candidate multicasts its priority. Each candidate that receives a multicast claim for leadership from another candidate compares its own priority against the claimant and only votes for itself if its own priority is higher. After a preconfigured period of hearing no other claimants with higher priority, the candidate with the highest priority becomes the new leader.

A system and apparatus for control and distribution of data files in large-scale distributed networks. Members of a group of servers in a multicast network elect a group leader whenever a new group leader is required, as detected by absence of a periodic message published by the leader. Election is carried out by a system of voting by each candidate whereby each candidate has a priority calculated from its configuration, and the server with the highest priority is configured to claim the leadership faster than the other candidates. As part of the claim, each candidate multicasts its priority. Each candidate that receives a multicast claim for leadership from another candidate compares its own priority against the claimant and only votes for itself if its own priority is higher. After a preconfigured period of hearing no other claimants with higher priority, the candidate with the highest priority becomes the new leader.

The illustrative embodiments provide a method and apparatus for controlling movement of a vehicle. User input selecting a path for the vehicle is received from an operator. The vehicle responds to the user input by moving along the selected path in a manner that maintains the operator on a side of the vehicle. The illustrative embodiments further provide a method and apparatus for improved machine control. The vehicle receives a power-up command, instructions to execute a planned path, and information identifying a leader. The leader is an operator. The vehicle then executes the planned path using the information identifying the leader in order to follow a path of the leader. The vehicle moves along the path in a manner that maintains the leader in a position proximate to a side of the vehicle.

Automatic homing systems are disclosed, operable between pairs of objects. One or both of the objects in the pair may be moving and / or unmanned. Examples of a pair of objects between which the inventive automatic homing systems may be operated are ground vehicles in leader-follower configuration, as well as aircraft, spacecraft, watercraft. The automatic homing systems are based on a relatively simple, elegant concept of rightness / leftness and a line-of-sight link between a respective leader vehicle and follower vehicle. Complex EO / IR cameras, LIDAR, RADAR, and / or SONAR-based sensor systems can be avoided. Convoys of vehicles in leader-follower configuration advantageously may be operated without needing human operators in the follower vehicles.

Improved methods, systems, and apparatus for inspecting a structure using angle beam shear wave through-transmission ultrasonic signals involves positioning transducers at offset positions on opposing sides of the structure and permits inspection of the inside of the structure beneath surface defects and features. Magnetic coupling can be used for supporting a pair of leader-follower probes and defining offset positions between angle beam shear wave transducers carried by the probes. Inspection data can be collected for supporting real-time generation of three-dimensional image representations of the structure and of internal defects and features of the structure. Image generation and resolution using inspection data from angle beam shear wave ultrasonic signals can be supplemented using pulse-echo ultrasonic inspection data.

The invention discloses a multi-robot formation method, belonging to the field of intelligent control. The method comprises the following steps of: controlling the whole formation motion trail by the leader motion trail, firstly, determining a kinematics model of the leader, and determining the direction of the motion of the leader according to a resultant force of a repulsive force and a gravitational force; creating a motion model of following the leader by the follower, following the leader by the follower according to certain distance and angle, and determining the motion trail of the follower according to a motion model created by the artificial potential field; introducing an AdHoc between the leader and the follower, creating information feedback, and ensuring that no loss occurs in the process of following the leader by the follower. With the method provided by the invention, a multi-robot system can successfully avoid obstacles in the process of finishing tasks to reach a target point, and also can keep initial order in the whole process, implement real-time order control on multiple robots and be more suitable for some occasions where multiple robots are needed for finishing tasks (such as transporting, rescuing and the like) synchronously.

The invention discloses an unmanned surface vessel formation control method based on a leader follow-up structure. The method is used for multiple fully-driven unmanned surface vessel systems, and a formation control method based on a leader-follower is provided to prevent any follower from colliding and being kept in connection with a leader thereof. The method comprises following steps of establishing a dynamic model of an unmanned surface vessel; setting a position output tracking error constraint condition of a follower; designing a tracking error conversion function; applying the dynamic surface control technology and designing a virtual controller; designing a disturbance observer for compensating external unknown interference like wind wave flows; and constructively designing a tracking formation controller. According to the invention, it is ensured that any follower is always kept away from the leader thereof for a certain safe distance, and is in a communication connection range of the leader thereof; and by use of the dynamic surface control technology, accelerated speed of the leader is prevented from being used and practicability of a design scheme is improved.

A leader location-determining receiver determines a leader location of a lead vehicle. A follower location-determining receiver determines a follower location of a follower vehicle, which has a container for storing a material. A data processor or position module calculates an observed relative position between the lead vehicle and the follower vehicle. Target relative positions are established between the lead vehicle and the follower vehicle. A data processor or selector selects a preferential one of the established target positions. A data processor or adjuster adjusts the observed relative position of the follower vehicle to achieve the selected preferential one of the established target positions.

Improved methods, systems, and apparatus for inspecting a structure using angle beam shear wave through-transmission ultrasonic signals involves positioning transducers at offset positions on opposing sides of the structure and permits inspection of the inside of the structure beneath surface defects and features. Magnetic coupling can be used for supporting a pair of leader-follower probes and defining offset positions between angle beam shear wave transducers carried by the probes. Inspection data can be collected for supporting real-time generation of three-dimensional image representations of the structure and of internal defects and features of the structure. Image generation and resolution using inspection data from angle beam shear wave ultrasonic signals can be supplemented using pulse-echo ultrasonic inspection data.

Embodiments of the present invention provide methods and systems for strong-leader election in a distributed computer system. In certain embodiments of the present invention, nodes employ a distributed consensus service, such as Paxos, to seek election of leader at or near the expiration of each of a set of successive lease periods. A current leader seeks re-election prior to expiration of the current lease, thus favoring continued re-election of the current leader until and unless the current leader fails or surrenders the leadership role.

This invention defines a method and mechanisms for maintaining a consistent group membership, based on the leader-follower strategy of Semi-Active or Passive replication. Each member of the group is assigned a rank, and a precedence, determined by the order in which it is added to the group. The Primary maintains the membership of the group, while each Backup monitors the behavior of the Primary. When a Backup detects that the Primary is faulty, the Backup announces that it is the new Primary and removes the faulty Primary from the membership of the group. The group membership algorithm disclosed here does not require a consensus decision to reconfigure the membership and effects a membership change more quickly in the common case where the Backup of lowest rank takes control as the new Primary when it determines that the existing Primary failed.

A method is provided for automatically controlling a first vehicle (follower vehicle) that is to follow a second vehicle (leader vehicle) in a desired manner with respect to movement of the second vehicle. In the follower vehicle, bearing and acceleration control inputs are generated based on data representing bearing and acceleration control inputs made at the leader vehicle and a position of the follower vehicle relative to the leader vehicle so as to mimic in the follower vehicle the bearing and acceleration control inputs made in the leader vehicle. Adjustments may be made to the control inputs applied in the follower vehicle based on deviation between the velocity of the follower vehicle and velocity of the leader velocity, and on deviation between estimated (actual) follow distance and lateral offset and target follow distance and lateral offset between the follower vehicle and the leader vehicle.

The robotic leader-follower navigation and fleet management control method implements SLAM in a group leader of a nonholonomic group of autonomous robots, while, at the same time, executing a potential field control strategy in follower members of the group.

The invention discloses the optimal consistency control method and system of a nonlinear multi-agent system. The method is characterized by establishing a reference behavior model according to the individual dynamic characteristic of a heterogeneous multi-agent system, and using a leader-follower control model to form a multi-agent system formed by reference behavior models; then, constructing a dynamic graph game global error dynamical model according to the network topology structure of multiple agents, defining a multi-agent local performance index function, and according to the global Nashequilibrium, acquiring a Bellman optimal equation; and then, under the condition of only using local agent information, using an execution-evaluation execution network framework mode based on value function approximation to carry out online iterative learning, and acquiring an optimal consistency protocol to achieve the consistency of each reference model behavior. Compared with the prior art, byusing the method and the system of the invention, under the condition of guaranteeing optimal control performance, the consistency problem of the complex multi-agent system can be high-efficiently solved, and an actual application value and high scalability are achieved.

The invention discloses a cooperative control policy based on secure communication of multiple unmanned aerial vehicles. The cooperative control policy comprises a first step of applying an Olfati-saber flocking control algorithm of a variable speed virtual leader to perform preliminary cooperative control over an unmanned aerial vehicle group; a second step of introducing a virtual communication circle to perform on-line communication power setting on each unmanned aerial vehicle, and calculating an expected position of each unmanned aerial vehicle node meeting the secure communication requirements; and a third step of applying an optimized position movement function to make each unmanned aerial vehicle node move to the expected position obtained in the second step securely without collision. According to the cooperative control policy, how communication affects unmanned aerial vehicle group dynamics and communication topology is studied more; through the newly provided virtual communication circle and by combination of an improved target movement function and an existing classic dynamics flocking algorithm, the problem of insecurity of information leakage possibly occurring to a multi-unmanned aerial vehicle system is effectively solved, and the cooperative control policy is a new idea for describing relations of unmanned aerial vehicle dynamics and wireless ad hoc networks.

Computer-implemented systems and method for sharing online information, such as browser sessions, between computer systems monitor information at a leader computer related to a status of the leader computer, pass a uniform resource locator (URL) associated with a status of the leader computer from the leader computer to a follower computer over a computer network, and automatically cause a browser window at the follower computer to be directed to the URL upon receipt of the URL over the computer network. Thus, a communicative leader-follower session is established between remote computers such that a follower browser follows a leader browser through various websites, thereby allowing sharing of the website history between computers. Many additional features and functionalities may be provided, while the total amount of data communicated between the computers is kept to a minimum.

The invention provides a leader-follower ratio consistency control method of a two-order multi-agent system. Following agents and leaders are determined according to a network topological structure; adirected generation tree structure using leaders as root nodes is determined; secondarily, the multi-agent state ratio relationship is realized according to the expectation; the proportional parameter is selected for the following agents, so that the two-order multi-agent state reaches the expected specified proportion relationship; finally, under the condition that one or a plurality of following agents can obtain the leader information, a leader-follower ratio consistency protocol is designed; the goal of strictly following the state of a leader according to a certain ratio in a way of following the agent state is achieved, so that the state of all following agents realizes the ratio consistency.

The invention discloses a navigation speed and navigation direction cooperative control formation navigation control method based on a leader-follower method. Compared with a routine formation navigation control method, the navigation speed and navigation direction control method has advantages of realizing definite control task assignment and definite physical meaning, overcoming a problem of incapability of settling controlling of formation keeping according to an artificial potential field method, realizing high engineering operability and high applicability, and realizing no requirement for artificial intervention. The navigation speed and navigation direction cooperative control formation navigation control method can be widely used for settling a ship formation navigation control method in an unmanned environment and is particularly suitable for satisfying a requirement in ship formation navigation of occasions such as a water target field and a high-danger water area. Particularly, through adding acceleration and navigation direction control restraining in a formation forming process, the method is suitable for formation forming and formation keeping controlling in formation controlling. Furthermore the method is particularly suitable for satisfying the navigation requirement of the ship formation in occasions such as the water target field and high-danger water area.

The invention discloses a finite time robust fault diagnosis design method for a leader-follower multi-agent system. The method includes the steps: firstly, building a multi-agent system connection diagram with a leader and showing the multi-agent system connection diagram by a directed graph to obtain a Laplacian matrix L of a follower and an adjacent matrix G of the leader; building a state equation and an output equation of each node flight control system and augmenting a state vector and a fault vector into new vectors; constructing a distributed error equation and a global error equation based on the directed graph for each node according to the built directed graph, constructing a finite time fault diagnosis observer of a flight control system based on finite time robust control, and performing finite time fault diagnosis for faults of a multi-agent executor based on the directed graph. Faults of an optional node of the control system or simultaneously occurring faults of a plurality of nodes are effectively and accurately diagnosed and estimated on line in finite time.

The invention discloses a Stackelberg game power control method based on interruption probability constraint in the cognitive radio network. A double-layer network is established. A main user serves as a leader in a model, and an interference price is set for a cognitive user; and the cognitive user serves as a follower, when the authorized frequency range of the main user is used, corresponding charge is paid to the main user, and thus, a corresponding utility function is set. An optimized game problem with constraint is established by taking the maximal emission power of the user, the threshold of interference temperature and interruption probability constraint into consideration. The optimal emission power of the main user and the cognitive user under the constraint condition can be obtained by solving the optimized game problem in the Lagrange decomposition method and KTT condition, an asynchronous distributed power control algorithm is provided for convergence to Nash equilibrium, and the complexity of the algorithm is greatly reduced. The network throughput is further improved, and the interruption probability of users is reduced.

The invention discloses a formation control method of mobile robots under constraint of a communication range. The formation control method of mobile robots under constraint of a communication range designs a formation controller for uncertainty of models for mobile robots and guarantees that the formation error eventually converges to zero point. The formation control method of mobile robots under constraint of a communication range includes the steps: constructing dynamic models for mobile robots; defining a distance variable and an azimuth variable between the i-th mobile robot and the leader of the i-th mobile robot in a leader-follower formation structure; designing a performance function for the formation distance error and the azimuth error; combining the performance function with the tan-type obstacle Lyapunov function and a backstepping design method, designing a formation controller; and using an adaptive control technology to solve the uncertainty problem of models in the controller design. The formation controller designed by the formation control method of mobile robots under constraint of a communication range enables each mobile robot in the leader-follower formationstructure to measure both the information of the leader of the each mobile robot and avoid collision with the leader, and the formation error satisfies the preset transient performance, and eventually can converge to the zero point.

A heterogeneous telecommunications system employs “out of band” signalling to automatically discover the identity of the two ports connecting two network elements through a specific link. Either of the connected network elements may be a circuit switching network element or a packet switching network element. One network element initiates the port discovery process and transmits an overhead signal, such as a SONET / SDH protection switching message, to the network element attached at the other end of the link. The other network element monitors the status of its ports and, when it detects a change in state at one of the ports, resulting from the first network element's transmissions, the receiving, or passive, network element recognizes the port as the port which forms a part of the link of interest. Each group of network elements, packet switching and circuit switching, elects a network element leader which coordinates requests for port identification.