Harbin Institute of Technology

Other

Liyi Li

Donghua Pan

Qingbo Guo

Yinxi Jin

Shengxin Lin

Kai Song

Chengming Zhang

Jiwei Cao

Yuxi Liu

Zhiyin Sun

Liguo Tan

Guodong Xia

Jinting Wang

Jiaxi Liu

Jiahong Yang

Jian Guan

Yi Li

Xun Ma

Hongtao Li

Songjie Li

Mingyl Wang

Jinshui Xiao

Chuanhui Kang

Siya Xiong

Mingjun Ding

Yiyang Zhao

Weijun Deng

Juan Zhao

Jiayu Zhai

Zhilong Zou

Yuyang Bai

Junjie Hong

Shidong Shao

Peng E

Jie Wan

Li Tan

Yanlu Chen

Yuhang Ge

Yiding Wang

The disclosure discloses a magnetic stimulation method with a controllable induced field direction, and belongs to the technical field of noninvasive neural regulation. The method includes the following steps: S, determining currents i, i, i, j=1, 2, . . . , n required to respectively generate unit vector electric fields at a target point P, when the currents i, i, i, are respectively applied through a coil j of a magnetic stimulation coil group, n≥3 and n being an integer; S, decomposing an electric field E required at the target point Pto three electric field components E, E, E; S, calculating currents I, I, Ithat respectively generate the electric field components E, E, Eat the target point P, I=Ei, I=Ei, I=Ei; S, generating the electric field E at the target point Pby applying a current I=I+I+I=Ei+Ei, I+Ei; through the coil j, j=1, 2, . . . , n.

Magnetic stimulation method with controllable induced field direction

Provided is a magnetic moment measurement system and method, which belong to the technical field of magnetic moment measurement, and solve the problems of insufficient accuracy, low efficiency, and vulnerability to disturbance from an external magnetic field in the existing magnetic moment measurement technique. The magnetic moment measurement method includes the following steps: acquiring a magnetic field vector and a magnetic gradient tensor at a center of a magnetic sensor array through the magnetic sensor array; calculating an angle of a magnetic moment vector; and according to the angle of the magnetic moment vector, selecting a corresponding magnetic moment inversion formula, and calculating the magnetic moment vector. By constructing the magnetic sensor array, and using the advanced inversion algorithm, this application not only significantly improves the magnetic moment measurement accuracy, but also greatly shortens the measurement cycle, simplifies the measurement system, and reduces the measurement error.

Magnetic moment measurement system and method

The present disclosure provides a data acquisition and control system of pulsed power supply for multi-load, and relates to the technical field of pulsed power. The system of the present disclosure is configured to control 18 sets of pulsed power supplies to provide 18 coils with stable and reliable excitation current featuring multiple output time sequences and flexible adjustability, such that a near-earth space plasma environment ground-based simulation device can simulate the magnetic field topology of the earth magnetosphere and realize a background magnetic field required by physical experiments. The system mainly achieves the following functions: control over charge and discharge of pulsed power supplies, selection of power supplies put in use, 'delay trigger' setting, voltage monitoring, status monitoring of key components and output current display; and it is also necessary to realize failure alarm and failure handling for the purpose of ensuring the safety of equipment and personnel.

Data acquisition and control system of pulsed power supply for multi-load

A three-dimensional force loading device for a motor spindle is provided, and relates to the field of motor spindle testing. The device including a bottom plate; a torque loading assembly configured for testing torque performance of the motor spindle, and the torque loading assembly is in transmission connection with the motor spindle; a sleeve shell rotatably sleeved on the motor spindle, the sleeve shell is fixed along an axis direction of the motor spindle; a radial force loading assembly configured for testing radial force performance of the motor spindle, and the radial force loading assembly is fixedly connected with the sleeve shell; an axial force loading assembly configured for testing axial force performance of the motor spindle; and a intermediate force transmission mechanism connected with the sleeve shell and the axial force loading assembly.

Three-dimensional force loading device for motor spindle

A demagnetization method for a multilayer shielding apparatus is provided. In the demagnetization method, the demagnetization is realized on the basis of a demagnetization coil system. The demagnetization coil system includes a plurality of turns of demagnetization coils (), a plurality of connection wires and a power supply module. The multilayer shielding apparatus includes at least two layers of shielding bodies (); all the layers of shielding bodies () are sleeved layer by layer from inside to outside; a plurality of turns of demagnetization coils () are wound on each layer of shielding bodies () at intervals; and one half of each turn of demagnetization coils () is located inside the wound shielding bodies (), and the other half is located outside the wound shielding bodies (). Each demagnetization coil () is connected to the power supply module through the corresponding connection wire.

Demagnetization method for multilayer shielding apparatus

Disclosed is a method for analyzing a blind zone of a magnetic detection method that can provide a complete distribution map of the detection blind zone within the entire zone of the magnetic target. The method comprises the first step of establishing a complete magnetic detection model to obtain calculated position and magnetic moment of a magnetic target that is detected by a magnetic gradiometer. The second step involves establishing a direction-attitude-sphere model to represent the entire zone of the magnetic target. The third step involves expanding the direction-attitude-sphere to a planar map layered by latitude and calculating success detection rates within the planar expansion map. Finally, the distribution map of the magnetic detection blind zone in the entire zone is visually presented in the planar expansion map and a complete distribution rule of the entire detection blind zone is thus obtained. This blind zone analysis method is applicable to any magnetic detection method and can provide a visual presentation of the entire detection blind zone. The knowledge of the detection blind zone can be applied to guide practical magnetic detection to avoid the detection blind zone so as to increase the detection accuracy.

Method for analyzing magnetic detection blind zone

Provided is a method for designing a magnetic gradiometer based on the combined influence of multiple influencing parameters. The method takes into consideration of synergetic interaction of the influencing parameters on the performance of a magnetic gradiometer. It analyzes detection errors within the entire zone of all possible directions and attitudes of a magnetic target under the influence of various influencing parameters, uses the detection accuracy and detection success rate to measure the performance of the magnetic gradiometer accurately and objectively, and finally obtains the influence rule of the influencing parameters on the performance of the magnetic gradiometer. Based on the knowledge of the combined influence of multiple influencing parameters, the magnetic gradiometer can be designed to have high detection accuracy and success rate and high cost-efficiency.

Method for making a magnetic gradiometer with high detection accuracy and success rate

A distributed demagnetizing coil system, a shielding device, and a demagnetizing method. The system includes turns of demagnetizing coils evenly wound on each shielding surface of a shielding body in the shielding device at intervals and connecting wires provided on outer side of the shielding surface in an inflection manner. One half of each turn is located on inner side of the wound shielding body and the other half of each turn s located on outer side of the wound shielding body for providing corresponding demagnetizing magnetic fields to form a closed magnetic flux loop. One half of each connecting wire is connected to the corresponding demagnetizing coil, the other half of each connecting wire is reversely inflected along an original path and is connected to a power supply module, so that corresponding demagnetizing current is introduced into each demagnetizing coil connected to the connecting wire.

Distributed demagnetizing coil system, shielding device, and demagnetizing method

An electromagnetic drive control system comprising an H-shaped full bridge driving circuit connected to a controlled electromagnetic unit, including a first field effect transistor (FET) and a fourth FET connected in series constituting the left arm of the H-shaped full-bridge driving circuit, and a second FET and a third FET connected in series constituting the right arm of the H-shaped full-bridge driving circuit; PWM control unit is used to provide control signal to the FETs of the left and right bridge arms; it is characterized in that: the left arm comprises a first DC voltage source connected in series to the drain of the first FET, and the right arm includes a second DC voltage source connected in series to the drain of the second FET so as to form a dual power circuit; in this configuration, the first DC voltage source and the second DC voltage source are configured appropriately to greatly weaken the output current ripple of the electromagnetic drive control system and allow the system to realize super-high precision control of the electromagnetic drive control system under lower switching frequency, as a result, it can improve the stability of the system, reduce the loss of the system, and significantly decrease the cost of the drive controller.

Electromagnetic drive control system

A motor cooling and eddy current suppression structure (), which is attached to the surface of the motor winding (), includes a first cooling plate (), a second cooling plate (), and a cooling water circuit located between the first cooling plate and the second cooling plate. The cooling water circuit is configured to allow the cooling fluid to pass through. The first and the second cooling plates are both non-magnetic metallic materials. The first cooling plate is divided into a plurality of individual first regions () which are corresponding to each pole of the motor by one or more first slits () provided on the first cooling plate in the position where the motor poles are combined. Each of the first regions is further divided into an even number of first sub-areas by at least one fist sub-slit () where induced electromotive force is generated. Two adjacent first sub-areas in respective first regions are grouped together, and the ends of each first sub-area that has the same polarity are connected in series. The second cooling plate is divided into a plurality of individual second regions which are corresponding to each pole of the motor by one or more second slits provided on the second cooling plate in the position where the motor poles are combined. Each of the second regions is further divided into an even number of second sub-areas by at least one second sub-slit where induced electromotive force is generated. Two adjacent second sub-areas in respective second regions are grouped together, and the ends of each second sub-area that has the same polarity are connected in series. This structure can efficiently reduce the temperature of the motor winding and reduce the induced eddy current.

Motor cooling and eddy current suppression structure

A thrust compensation system of a dual-winding voice coil motor, which is used for driving the voice coil motor having main windings () and secondary windings (), wherein the secondary windings () of the voice coil motor are between each pair of the main windings (). The system includes a switch drive circuit of the main windings () which is powered by a first controlled voltage source to drive the main windings () adopted as the main working windings of the voice coil motor and used for providing the output electromagnetic force required by the driving system of the voice coil motor in work; a switch drive circuit of the secondary windings () which is powered by a second voltage source to drive the secondary windings () adopted as compensation windings, and used for providing the thrust ripple opposite to the main windings () so as to compensate the thrust ripple of the main windings () and keep the resultant force of the output of the main windings () and the secondary windings () of the voice coil motor in constant; wherein the voltages Uand Uof the first and second controlled voltage sources of the main windings () and the second windings () are configured as meeting a certain relationship.

Thrust compensation system of dual-winding voice coil motor

A thrust compensation system of a dual-winding voice coil motor, which is used for driving the voice coil motor having secondary windings arranged between each pair of main windings, wherein the main windings are the main working windings of the voice coil motor and used for providing the output electromagnetic force required by the driving system of the voice coil motor; the secondary windings are compensation windings and used for providing the thrust ripple opposite to the main windings and compensating the thrust ripple of the main windings, so that the resultant force of the output thrust of the main windings and the secondary windings of the voice coil motor is constant. The scheme provided by this invention not only greatly reduces the thrust ripple of the servo system of the voice coil motor, but also realizes the ultra-high precision control of the servo drive system of the voice coil motor when the system is under low switching frequency, improves the stability of the system, reduces the system loss, and greatly reduces the cost of the drive controller.

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Harbin, China

Liyi Li