66 results about "Fault tolerant algorithms" patented technology

Provided is a routing position data secrecy storing and sharing method based on block chains. The routing position data secrecy storing and sharing method includes a data storing method and a data sharing method. The data storing method includes the steps of node configuration, data encryption sending, storage subnetwork verification storing, etc. The data sharing method includes the steps of demand generation, demand response, sharing achievement and the like. The effects of the invention are as follows: through a block chain technology, data sharing is realized through data encryption storage and a decentralized network to solve the problems that data storage parties have no right to use data and users do not have channels to selectively enable personal data to be accessed; local encryption sending is adopted during data storage, service parties store encrypted data, the users themselves save decryption secret keys, and the service parties have no access to original data, so a better data protection effect is achieved; and the block chain technology is adopted during storage, commonly recognized storage is realized through a practical Byzantine fault-tolerant algorithm, workload bottleneck problems of centralized storage are solved, and data is prevented from being tampered.

A fault tolerant control system for a multi-phase permanent magnet assisted synchronous reluctance motor utilizes vector control to provide safe operation under various phase loss fault conditions. Specifically, the vector control of the present invention utilizes a fault tolerant algorithm that receives a torque input and an electrical current feedback signal from the motor. Thus, in the presence of a fault condition, the vector control applies the optimal torque angle to the motor, while reducing the phase currents to an optimized value to lessen the saturation effect in the motor, so as to ensure that the motor delivers maximum torque output in the presence of such faults. As such, the control system allows the motor to operate safely with high reliability, which is highly desirable, such as in electric vehicles and the aerospace industry.

The invention provides a private block chain block building method for a Byzantine fault tolerant algorithm of quartic communication. The method comprises: (1) all nodes carrying out hash mapping on the received transactions to obtain a bitarray sent to all remaining nodes, and each node carrying out 2 / 3 AND operation on the received bitarray to obtain a bitarray corresponding to a transaction intersection of over 2 / 3 nodes; (2) a block building node obtaining a transaction set according to the bitarray for building a block, and submitting the block to the remaining nodes; (3) a node receiving the block completing verification by comparing self bitarray with the transaction set in the block, and sending a digital signature of the verification result to all the remaining nodes after verification; and (4) forwarding all vote signatures received by all nodes on the block in second vote so that each node receives votes of all the nodes, and collecting statistics on the votes to obtain a final result, thus determining whether to accept the block.

A simplified fault tolerant algorithm is presented for operating a distributed computing system in a fault tolerant manner. A system comprising three computing devices need only have two devices agree to perform any proposed function. Thus, when soliciting a vote for a proposed function, a leader device can also send its vote for the proposed function. This allows any recipient device to complete the quorum with its own vote. Consequently, any recipient device can, without any further messages, determine whether to execute the proposed function. Furthermore, if the device executes the proposed function, it can transmit the results directly to the client that requested the function, saving a message delay. If the quorum of devices used to select and execute proposed functions is itself selected by a quorum, then one of the devices of the system can be an inexpensive device having limited computational ability or storage capacity.

The invention provides a consensus method, device and system based on effective computational force contribution. The method includes the steps of receiving computational tasks issued by a computational publisher and computational requirements corresponding to the computational tasks; configuring computing tasks according to computing requirements; obtaining the data needed by the computing task and compiling the computing task into a Boolean circuit; forming a plurality of parallel computing tasks, and distributing the parallel computing tasks to a plurality of computing nodes for computing;receiving the calculation result and the calculation proof of the parallel calculation task by the calculation node, and determining whether the calculation result is valid or not according to the calculation proof; if it is valid, determining the cumulative calculation contribution value of the calculation node corresponding to the calculation result, and allocating the preset reward for each calculation node; receiving voting data of each computing node as cumulative calculated contribution value, and voting on the candidate nodes; obtaining the N consensus nodes, wherein the practical Byzantine fault-tolerant algorithm is used to complete the consensus of the block data among the N consensus nodes.

The invention discloses a data processing method for the Internet of Things based on a block chain, and the method comprises the steps that a first consensus node generates a data block according to terminal information data when the terminal information data is received, and stores the data block on the data block chain; and when the user transaction data is received, the second consensus node generates a transaction block according to the user transaction data, and stores the transaction block on the transaction block chain. The invention further discloses an internet of things based on theblock chain and a storage medium. According to the invention, the terminal information data in the Internet of Things is stored in the data block chain based on the workload consensus mechanism; usertransaction data is stored in a transaction block chain based on a practical Byzantine fault-tolerant algorithm; a hybrid consensus mechanism is adopted in the Internet of Things, the advantage of high decentralization degree of a workload consensus mechanism and the advantage of high consensus efficiency of a Byzantine fault-tolerant algorithm can be effectively combined, and the consensus security level and consensus efficiency of the Internet of Things based on the blockchain are greatly improved.

A simplified fault tolerant algorithm is presented for operating a distributed computing system in a fault tolerant manner. A system comprising three computing devices need only have two devices agree to perform any proposed function. Thus, when soliciting a vote for a proposed function, a leader device can also send its vote for the proposed function. This allows any recipient device to complete the quorum with its own vote. Consequently, any recipient device can, without any further messages, determine whether to execute the proposed function. Furthermore, if the device executes the proposed function, it can transmit the results directly to the client that requested the function, saving a message delay. If the quorum of devices used to select and execute proposed functions is itself selected by a quorum, then one of the devices of the system can be an inexpensive device having limited computational ability or storage capacity.

The invention relates to a finite-time posture fault-tolerant control method for a spacecraft formation and belongs to the technical field of multi-spacecraft formation flying. In order to reduce communication paths and avoid resource waste, a directional communication topological structure with small communication traffic is adopted between spacecraft formation members; in addition, in order to make a spacecraft formation posture control system achieve synergy more quickly and stably, the finite-time posture fault-tolerant control method for the spacecraft formation is provided on the basis of a finite-time algorithm with high robustness and fast convergence, a redundant fault-tolerant algorithm with better fault-tolerant performance and an self-adaptive algorithm with a good suppressioneffect on system uncertainty and interference. According to the method, a limited-capacity self-adaptive posture cooperative tracking fault-tolerant control strategy is perfected, a redundant fault-tolerant control method is achieved through reasonable torque distribution, and at the same time, a self-adaptive law is designed for reducing the influence of inertia variation and interference; moreover, fast convergence of a spacecraft cooperative tracking error system can be realized, and the robustness and practicability of the control system are further improved.

The invention provides a data storage method and device based on a redundancy mechanism and a server. At the server side, the method comprises the steps that the state of a data file is checked according to a preset period, and a cold data file with an access rate smaller than a first preset access rate threshold is found; the cold data file is fragmented according to a preset data fragmentation backup fault-tolerant algorithm, and all data fragments are stored into different storage nodes; the cold data file is deleted; and storage node information of all the data fragments is recorded. According to the method, the data file with a low access rate is fragmented and stored by use of the data fragmentation backup fault-tolerant algorithm (e.g., an IDA data fragmentation algorithm), and a certain storage space can be saved on the premise of guaranteeing data security and integrity.

The invention discloses a fault-tolerant control method for a single-phase open-circuit fault of a five-phase permanent magnet synchronous motor with improved SVPWM. The method comprises the followingsteps: obtaining a variety of SVPWM fault-tolerant control methods corresponding to different solutions of control parameters by the algorithm according to the existing five-phase SVPWM fault-tolerant control theory, solving the optimal solution of the control parameters to reconstruct the post-fault system coordinates by analyzing the direct current bus voltage utilization and phase current harmonic suppression ability of the motor, and performing redistribution and district reconstruction of spatial vectors on the reconstructed coordinate system. Compared with the prior art, the fault-tolerant control method effectively reduces the current harmonic content, restrains the motor torque ripple, and simultaneously improves the direct current bus voltage utilization rate while ensuring thatthe average torque outputs of the motor before and after the single-phase open circuit fault are constant. More critically, the fault-tolerant algorithm may achieve high dynamic performance fault-tolerant operation of the motor and has certain versatility.

The invention relates to a spacecraft amplitude limiting adaptive attitude cooperative fault tolerant control method, which belongs to the technical field of multi-spacecraft formation flying. A redundant fault-tolerant algorithm is used to process a spacecraft fault. A control torque saturation controller carries out torque amplitude limiting. An adaptive algorithm control term compensates for inertia variation and external disturbance, and a fast convergence control algorithm is used for fast attitude cooperation. Other algorithms are used. The spacecraft amplitude limiting adaptive attitudecooperative fault tolerant control method is proposed. According to the invention, the consideration of a torque actuator fault, torque amplitude limiting, external disturbance and inertia variationuncertainty is more advanced; a spacecraft cooperative tracking error system can quickly converge; and the robustness and practicability of a control system are further improved.

The invention relates to the field of block chains, in particular to a practical Byzantine fault-tolerant algorithm improvement scheme for an alliance block chain, which is a consensus scheme capable of being used for the alliance block chain. The consensus algorithm mainly used in the alliance block chain is a practical Byzantine fault tolerant algorithm (PBFT), but the PBFT algorithm has the problems of low security, low efficiency and the like. According to the method, the characteristics of the alliance block chain are utilized, and an improved PBFT (Credit Recurrent PBFT, CRPBFT) scheme is provided. In the scheme, a credit mechanism is introduced to monitor the consensus behavior of the node to ensure that the Byzantine node is effectively checked out, so that the probability that the Byzantine node becomes a consensus node is reduced; secondly, nodes are selected according to the resource contribution amount, the reliability and stability of the nodes are guaranteed to the maximum extent, and the system enters a virtuous circle; and finally, the security and consensus efficiency of the algorithm are improved by adding a candidate consensus node set and removing Byzantine nodes.

The invention provides a reconfigurable fault-tolerant type driving topological structure of a redundant power source and belongs to the field of high-reliability motor driving control systems. The reconfigurable fault-tolerant type driving topological structure of the redundant power source comprises double power sources, N H-bridges, fuses, a reconfiguration switch and the like. The reconfigurable fault-tolerant type driving topological structure of the redundant power source is characterized in that in normal work, an independent H-bridge driving topological structure is applied to each phase, reconfiguration of the driving topological structure is achieved through switching on or switching off of the reconfiguration switch on the driving topological structure, namely, a fault can be isolated through the reconfiguration switch when the open-circuit fault or the short-circuit fault occurs on the power sources, power tubes and the reconfiguration switch, according to the type of the fault and the needs, the independent H-bridge driving topological structure of each phase can be reconfigured into star-shaped driving topology, finally, the fault tolerance function is achieved, and the reliability of the motor driving control system is improved. The reconfigurable fault-tolerant type driving topological structure of the redundant power source has the advantages of being flexible in power supply, capable of rapidly and conveniently isolating the fault and conducting hardware reconfiguration, rapid, strong in fault tolerance ability, flexible in use, free of an extra fault-tolerant algorithm, high in reliability and the like.

The invention discloses a fault-tolerant control method of a dual-motor synchronous control system. A feedback rotating speed and a rotor position are input into a synchronous control unit, three-phase currents of double motors are converted through Park and Clark to obtain respective feedback quadrature-direct axis currents, corresponding torques are input into the synchronous control unit to becompared, and a corresponding angle and speed compensation strategies are determined; a quadrature-axis reference current and a direct-axis reference current are compared with the feedback quadrature-direct axis current of the double motors, and respective quadrature-direct axis reference voltages are calculated; Park inverse transformation is performed on the quadrature-direct axis reference voltage of the double motors to obtain two voltage components under a static coordinate system, and three duty ratio signals are obtained; and a fault bridge arm of the inverter is judged by detecting a three-phase current of the double motors, fault signals are sent to a fault-tolerant inverter and a PWM signal logic synthesis unit to complete reconstruction of a fault-tolerant topology and implementation of a fault-tolerant algorithm, and finally fault-tolerant control of the double permanent magnet synchronous motors is achieved. System reliability is high.

The invention discloses a sinusoidal or trapezoidal counter potential five-phase permanent magnet motor short-circuit fault-tolerant control method adopting dead-beat current tracking. According to the method, the third harmonic space of the five-phase permanent magnet motor in a fault state is fully utilized, and a fault-tolerant control strategy for the five-phase permanent magnet motor with sine counter electromotive force and trapezoidal counter electromotive force under the condition of a single-phase short-circuit fault is provided, so that the third harmonic space of the five-phase permanent magnet motor can be fully utilized during fault-tolerant operation of the five-phase permanent magnet motor. According to the invention, the performance of the output torque of the motor in a fault state is improved, and the fault-tolerant operation efficiency of the motor is improved, so that the motor can have better fault-tolerant performance and dynamic response; the speed regulation range during fault-tolerant operation of the motor is widened, so that the motor can be better applied to the application fields, such as electric vehicles, requiring high reliability and wide speed regulation range; and compared with a current hysteresis modulation method used in a traditional fault-tolerant algorithm, the switching loss of the inverter is reduced.

Disclosed is a fault-tolerant algorithm of a human body sensor. The human body sensor is provided with a power circuit, a microprocessor, a human body infrared sensor body which is connected with the microprocessor, a microwave Doppler sensor, a switch driving circuit and a control switch which is connected with the switch driving circuit. The fault-tolerant algorithm set by the microprocessor comprises the following steps that (1) under the situation that the control switch is connected, the microprocessor conducts N times of sampling on the human body infrared sensor body in the sampling period T1, and if the number of times when a human body is detected is zero, then the step 2 is executed; (2) the microprocessor turns off the control switch and conducts M times of sampling on the microwave Doppler sensor in the delaying time T2, and if the number of times when a human body is detected is zero, then the step 3 is executed; otherwise, the microprocessor conducts the control switch completely again and the step 1 is executed; (3) the microprocessor turns off the control switch completely, and conducts N times of sampling on the human body infrared sensor body in the sampling period T1, if the number of times when the human body is detected is not zero, the microprocessor conducts the control switch and the step 1 is executed.

The invention discloses a steering-by-wire system test bench, which comprises the design of a master control module, a fault-tolerant module, a steering control module, a steering execution module and a resistance loading module and connection parts thereof. A steering wheel is connected with a steering-column-assisted type steering gear to simulate road surface feedback; and two pinion-and-rack type steering gears with different power are connected by means of the parts, receive sensor signals by means of a master control single chip microcomputer, and realize steering and resistance simulation through transmitting PWM signals by using an Flexray bus. The mechanical connection between steering execution and operation is reduced, a transmission ratio and road feeling can be designed freely to change force transmission characteristic and angle transmission characteristic of the system, the layout space of a vehicle is saved, and the operation stability of the vehicle is improved. The steering-by-wire system test bench can simulate the road surface resistance in various states, and improves the precision of the system. The construction method of the SBW test bench disclosed by the invention is simple and effective, and can be applied to the experimental study of an SBW system control algorithm, a fault-tolerant algorithm and a bus technology.

The invention relates to a block chain medical data sharing excitation method based on a Shapley value, and belongs to the technical field of block chain network application. A block chain medical data sharing excitation method is established; alliance revenue is distributed among cooperation alliance members by using a Shapley value method, the excitation problem of medical data sharing in a block chain application scene is solved, and the proposed block chain medical data sharing excitation method can effectively excite the cooperation alliance members to participate in cooperation and sharereal data. According to the method, the contribution degree of a data owner and the weights of all members in a cooperation alliance are considered, so that a revenue distribution scheme based on a Shapley value method is suitable for a medical data sharing scene with contribution degree difference; a fair reward mechanism is formulated for consensus nodes in an alliance chain network according to practical Bayer's space fault-tolerant algorithm characteristics applied to the alliance chain.

The invention relates to the field of a consensus algorithm of a block chain distributed node, in particular to a hierarchical concurrent Byzantine consensus method and system applying a digital signature technology. The method comprises the following steps: a node which creates a block in a sliding time window is elected as a leader node to participate in consensuses, a creation node of a newestblock is used as a supreme leader node, and a stock right pyramid is built from big to small according to stock rights; the stock right pyramid is sequentially checked and adjusted from top to bottom;after the adjustment is completed, the consensus of each piece of transaction information is initiated by the supreme leader node, and the consensuses are carried out in each consensus group sequentially from top to bottom; message transmission is carried out in a digital signature mode during the consensuses; after the consensuses of all consensus groups are completed, a consensus result of current transaction information is broadcast to the whole network, and then the consensus of the next piece of transaction information is started; and when a new block is created, the sliding time windowslides backwards for one block, and the above steps are repeated. The defects of an application of a Byzantine fault-tolerant algorithm to an open block chain can be overcome.

The invention designs an optimized practical byzantine fault tolerance (OPBFT)applicable to a block chain. The OPBFT is used for solve the problems that a traditional Byzantine algorithm cannot dynamically sense the number of nodes and the efficiency of electing malicious nodes is low. In order to solve the problem of node adding, a node dynamic adding and quitting mechanism is introduced in the method, node adding and quitting need mutual confirmation among all nodes, and the confirmation process is divided into four stages, namely request, confirmation, reply and completion. In order to solve the problem of randomness of main node selection, a scoring and voting collaborative mechanism is introduced, the scoring mechanism follows the longest chain principle of a block chain, and the voting scoring mechanism is cooperatively carried out. A node adding and quitting mechanism in the method enables the number of consensus nodes to be variable, and the practicability of a consensus algorithm is greatly improved. A scoring and voting cooperation mechanism greatly ensures the correctness of the selected main node and improves the security of the system.

The invention relates to an alliance blockchain network consensus method based on mixed Byzantine fault tolerance, and belongs to the technical field of blockchains. The method comprises the steps that S1, a fragmentation mechanism is utilized to classify blockchain network nodes into four node types including common nodes, verification nodes, sorting nodes and block output nodes, wherein the output blocks are all nodes; S2, due to the characteristics of a parallel Byzantine fault-tolerant algorithm, dividing a consensus mechanism into two stages, including a preprocessing stage algorithm andan execution stage algorithm, and executing the preprocessing algorithm; S3, in order to ensure the correctness of the parallel Byzantine fault-tolerant algorithm, the normal operation of the main node in a consensus mechanism is ensured by utilizing a main node view switching algorithm; and S4, the parallel Byzantine fault-tolerant algorithm is executed by the output block nodes to achieve a consensus of the output block nodes, and block output is completed by the main node in the consensus of this round. Compared with the consensus mechanism in the current alliance block chain, the securityof the consensus mechanism and the consensus reaching efficiency of the node are improved.

The invention discloses a high-winding-factor permanent magnet brushless motor and a design and fault-tolerant control method. The high-winding-factor permanent magnet brushless motor comprises a stator, an armature winding, a rotor and a permanent magnet, wherein an armature groove is formed in the stator, and the armature winding is placed in the armature groove; double-layer winding is adopted. An air gap is arranged between the stator and the rotor, and a permanent magnet is attached to the surface of the rotor, and is magnetized by using a Halbach array structure. The motor is an eight-phase motor, and phases are evenly distributed at a phase belt angle of 45 degrees; after the phases are distributed, four phase line terminals and a common neutral point are led out. The single-phase open-circuit fault-tolerant algorithm of the motor of the invention solves the problem that the fault-tolerant algorithm can be implemented only by utilizing the phase which and the fault phase has a difference of 180 degrees when the ordinary four-phase motor is in a single-phase open-circuit fault state, and the capacity of an inverter and the insulation rating of the motor winding can be reduced by the fault-tolerant control strategy of the motor. Finally, the motor of the invention and the control algorithm have good fault-tolerant effects, and the average torque after fault tolerance is basically consistent with that in the normal operation.

The invention discloses a vision measurement location and correction system based on a dynamic routing mechanism, which comprises a location algorithm module, a scheduling algorithm module and a correction and fault-tolerant algorithm module, wherein the location algorithm module is in charge of realizing the basic location of the whole system, and is the core of the whole system; and the scheduling algorithm module realizes the non-interference scheduling of internodal sensors, collects and integrates the information of a plurality of sensors; and the correction and fault-tolerant algorithm module realizes the correction of node locations, searches and is fault-tolerant to the lost nodes. The vision measurement location and correction system has the characteristics of higher precision, very strong adaptivity, large measurement location scope and the like, the location precision is further improved, a vision fault-tolerant mechanism is built by utilizing an extraction algorithm of a characteristic area in the environment, the safety and stability of the system are increased, and the vision measurement location and correction system is particularly suitable to indoor location and unknown environmental survey.

The invention discloses a distributed flight control computer control system based on MPC8280. The MPC8280 and a FlexRay bus are effectively combined and used for the aviation field. The system meets the requirements of flight control, flight simulation and other applications, makes up for the blank that the MPC8280 and the FlexRay bus are used for the field of flight control in the prior art, and solves the problem that a fault tolerant algorithm, an aircraft control law and task logical processing are complex in the existing field of flight control.

The invention provides a consensus resource slicing method based on a block chain, and relates to the technical field of block chains. The improved block chain consensus resource slicing method is based on a traditional practical Byzantine fault-tolerant algorithm (PBFT) consensus mechanism, and specifically comprises the steps of performing slicing management on consensus resources in a block chain system, dividing consensus nodes into a plurality of different consensus sets, and concurrently performing consensus on the plurality of consensus sets. Meanwhile, in order to ensure the stabilityof the consensus process, a main node with a high stability value is dynamically selected through the stability value, the main node generates a plurality of preparation blocks from the collected dataneeding consensus, each consensus set performs consensus on the corresponding preparation block, and finally, the main node generates a formal block from the data passing the consensus. Compared withthe prior art, the phenomena of low throughput in the consensus process and resource waste in the consensus process are mainly solved, the throughput of the blockchain system can be improved, and theconsensus resource waste is reduced.

The invention discloses a crowdsourcing transaction method and system, a readable storage medium and a terminal. The method comprises the following steps of receiving the registration information of apacket receiver and a packet sender through intelligent management equipment in a crowdsourcing transaction platform, and when the registration information of the packet sender and the packet receiver passes the authentication, writing the registration information of the packet sender and the packet receiver into the block chain in the crowdsourcing transaction platform by adopting an improved Bayer fault-tolerant algorithm. According to the scheme, the malicious nodes can be effectively prevented from tampering data, the problem of leakage of crowdsourcing transaction data is avoided, and therefore the security of crowdsourcing transaction can be improved.

The invention relates to a block chain consensus node selection method and device, computer equipment and a storage medium. The method comprises the steps of broadcasting verification information of the node to other nodes in the block chain, and when a set number of first verification passing information is received, determining the node as a candidate node; and when the node is a candidate node, broadcasting verification information of the candidate node to a plurality of candidate nodes in the candidate node set, and when a set number of second verification passing information is received, determining that the candidate node is a main node. Compared with a traditional method for selecting nodes through proven of rights and interests or a practical Byzantine fault-tolerant algorithm, according to the scheme, multiple rounds of verification are carried out by utilizing verification information formed based on various node information and a verifiable random function, the randomness of node selection is improved, network attacks carried out through predicted nodes are prevented, and the effect of improving the node security is achieved.

The invention discloses a block chain backup for disaster recovery system, method, server and a computer readable storage medium. Block chain nodes are deployed to a first primary machine room, a standby machine room and at least one second primary machine room. When the downtime node amount is greater than the fault-tolerant capacity theoretic value of the practical Byzantine fault-tolerant algorithm, the standby machine room is started through the block chain backup for disaster recovery server to perform the backup for disaster recovery. Compared with the prior art, the system availabilityof the system is guaranteed while performing the backup for disaster recovery of the block chain.

The invention discloses a software-defined opportunistic network flow table updating method based on a practical Byzantium fault-tolerant algorithm. The method comprises the following steps: firstly,a control layer sending an initial flow table to be updated to all switches; the first switch forwarding the received initial flow table to be updated; when the other switches receive the first flow table forwarded by the first switch, the first flow table being switched to the second flow table; matching the content of the first flow table with the content received by the first flow table; if thematching is successful, the first flow table being continuously forwarded to other switches; and if the number of the first feedback information received by a certain switch exceeds a preset value, the switch entering a confirmation state and forwards own states to other switches, and when the number of the switches finally entering the confirmation state exceeds the preset value, each switch updating the flow table. According to the method, the PBFT algorithm of the block chain is used for solving the problem of inconsistent updating of the flow table, reliable distribution of the flow tablecan be ensured, and extremely high fault tolerance is achieved.