34results about How to "Reduced dynamic performance" patented technology

The invention discloses a two-freedom degree motion-decoupling flexible hinge mechanism. The mechanism comprises a flexible hinge matrix and a driving branched chain. The flexible hinge matrix comprises flexible hinge branched chains and a rigid connection member. The rigid connection member comprises a terminal rigid output platform located in the middle of the flexible hinge matrix, and upper, lower, left and right rigid platforms respectively located at upper, lower, left and right parts of the flexible hinge matrix. The upper, lower, left and right rigid platforms are respectively connected to the terminal rigid output platform by the flexible hinge branched chains and are respectively connected to the rigid matrix of the flexible hinge matrix by the flexible hinge branched chains. The two-freedom degree motion-decoupling flexible hinge mechanism realizes decoupling of motion and forces of the terminal along all directions and is conducive to improvement of a motion precision.

The invention relates to a cam curve design method based on a k-order harmonic function, which belongs to the technical field of cam design. The invention aims to solve the problem that the existing harmonic cam curve is unsuitable for high-speed occasions due to mechanism fluctuations caused by some characteristic parameter curves approaching infinity at the endpoints. It includes: obtaining the key point data determined by the cam to realize the function; dimensionless the key point data to obtain the dimensionless time T and dimensionless displacement S; writing the cam curve fitting program to obtain the k-order harmonic function Add local control points to the first cam curve expression; after solving, deform to obtain the second cam curve expression, then combine the first two expressions to obtain the final cam curve expression, determine the order of k, and add local control points, An optimized cam profile is obtained. The invention is used in the design of cam curves.

The invention belongs to the technical field of machine designing and manufacturing and particularly relates to a parallel type macro-micro high-precision movement platform. The parallel type macro-micro high-precision movement platform is characterized in that a first linear driving system and a second linear driving system are parallel to each other and are symmetrically fixed to the front side and the rear side of the plane of a base (1) respectively; a terminal platform (2) is in a Y shape, and the three top ends of the terminal platform are connected with one ends of three identical branched chains respectively; the other end of the first branched chain and the other end of the second branched chain are hinged to a first linear feeding platform (17); the other end of the third branched chain is hinged to a second linear feeding platform (35); the two linear feeding platforms are connected with linear guide rails of the systems of the two linear feeding platforms respectively through guide rail sliding blocks; linear grating rulers are parallel to the linear guide rails; a plane grating (54) is fixedly installed on the base (1); flexible hinge units are embedded into the branches chains; a pressure sensor is fixedly installed at the tail end of a piezoelectric ceramic actuator. According to the parallel type macro-micro high-precision movement platform, a flexible unit design mode of input decoupling is adopted, and the parallel type macro-micro high-precision movement platform has the characteristics of being high in movement precision and high in resolution ratio.

The invention relates to an access method in a 5G system. On the user side, a soft SIM card is used to share an ID, and the user equipment can dynamically modify the ID number of the SIM card. All user equipment sharing the ID will have the same ID, and then based on The non-orthogonal multiple access authorization-free transmission scheme accesses the network; on the network side, through the authorization-free orthogonal access method, the signaling burden on the control plane of the user access network is reduced, and at the same time, on the core network side, all users with the same ID The user equipment is assigned the same data bearer; when a large number of equipment are connected at the same time, it can effectively reduce the signaling load burden on the control plane of the access network and the core network, improve the resource utilization efficiency of the network equipment, and ensure the normal access of users for data transmission .

The invention discloses a feed-forward decoupling control method of a three-phase two-arm three-level active power quality compensator. In order to realize reactive power, negative sequence and harmonic compensation, a two-input and two-output coupling The system is decoupled into two independent single-input and single-output systems to realize fast tracking of the current and improve the reliability of the system, and then drive the switching tube to obtain the desired current by using the corresponding PWM modulation method. The feed-forward decoupling deadbeat control method of the three-phase two-arm three-level active power quality compensator can realize the complete compensation and suppression of the system negative sequence and harmonics.

The invention relates to an air bearing, in particular to a pressure-sharing cavity air thrust bearing which comprises at least one air floatation sliding block; a supporting surface of each air floatation sliding block is provided with at least one pyramid pressure-sharing cavity; the supporting surface is opposite to a substrate; the conical bottom surface of the pyramid pressure-sharing cavityis flush with the supporting surface; the peak of the pyramid pressure-sharing cavity is provided with an orifice; the orifice is communicated with an air supply pipeline which is arranged in the airfloatation sliding block; and the air supply pipeline is communicated with an external pressurizing air source. According to the invention, a diverging pyramid pressure-sharing cavity is adopted so that the high-pressure air more easily flows out along a parallel streamline when the high-pressure air flows in a bearing clearance through the orifice, the bearing vibration phenomenon educed by vortex close to the orifice is restrained, and the harm of micro vibration on the static and dynamic performance of the whole moving system is reduced.

The invention relates to a method for controlling a multicylinder internal combustion engine. The cylinders are synchronised for adjusting the torques of the individual cylinders, said torques forming the total torque of the internal combustion engine. The cylinder synchronisation is checked for efficiency. At least one error signal that indicates a failure is generated when the cylinder synchronisation fails.

The invention discloses an analog-digital converter circuit adopting the partial multiplex technique of a multistage amplifier. The analog-digital converter consists of a flash structure and at least one combination flow stage. The flash structure is taken as the last stage of the flow stages, and the combination flow stage comprises a first flow stage and a second flow stage, wherein, the first flow stage consists of a first stage sub-amplifier A1, a second stage sub-amplifier A2, and a third stage sub-amplifier A3 in series sequentially; the second flow stage consists of a second stage sub-amplifier A2, a third stage sub-amplifier A3, and a fourth stage sub-amplifier A4 in series sequentially; and the second stage sub-amplifier A2 and the third stage sub-amplifier A3 are shared by the first flow stage and the second flow stage. By adopting the analog-digital converter circuit, the consumption of an amplifier and a system thereof is cut, and the design complexity and the dynamic performance are reduced.

The invention aims to provide a vector control asynchronous motor speed adjusting method combining pole changing with frequency changing and provides a pole-changing asynchronous motor speed adjusting system which comprises a pole-changing asynchronous motor, a frequency-changing power source, a pole-changing control circuit and a control system. The frequency-changing power source powers the pole-changing asynchronous motor through the pole-changing control circuit which is controlled by the control system, the control system actually measures rotating speed of the pole-changing asynchronous motor, and a connecting mode of stator windings of the pole-changing asynchronous motor is YY / Y connection. When voltage of the motor increases to a rated value along with frequency (the rated value corresponds to rotating speed (i)n( / i)> / =(i)n( / i)1N), a pole-changing operation is performed on the pole-changing asynchronous motor, and reconstruction (i)U( / i) / (i)f( / i) is performed according to new motor parameters after pole changing and current rotating speed to enable a constant-torque speed adjusting range of a system to be expanded under new parameter conditions, so that the objective of expanding a constant-torque speed adjusting range of the motor without increasing voltage of the power source and number of inversion circuit semiconductor switch devices is achieved.