32results about How to "Reduce hardware complexity" patented technology

The application provides a kind of intelligent metasurface assisted near-field time division integrated sensing method and system, it is related to wireless communication field.The application designs integrated sensing system by introducing RIS and single antenna receiver, avoids complex full-duplex base station and multi-antenna receiver, significantly reduces hardware complexity and implementation cost under the premise of ensuring high-quality communication and sensing performance;The adjustable frame structure designed separates the communication subframe and the sensing subframe completely, decouples the communication beam optimization and the sensing signal design, respectively realizes the communication and sensing functions in a purer signal environment;In the communication subframe, the communication and rate maximization are realized, and in the sensing subframe, the sensing capability is enhanced through the transmission beam pattern matching, which significantly improves the overall communication rate and sensing accuracy of the system;Finally, a virtual multi-dimensional receiving signal of multiple passive targets in the near field of RIS is constructed through repetition coding design, and then the 2D-MUSIC algorithm is used to estimate the target angle and distance parameters.

This invention discloses a virtual synchronous low-voltage ride-through control method and system for wind turbines with energy storage coordination. The method includes: real-time acquisition of operating parameters of the wind turbine grid connection point and the energy storage system; determining low-voltage faults based on the effective voltage value of the grid connection point and calculating the voltage drop depth; adaptively updating the virtual inertia and damping coefficient based on the drop depth, and calculating the stator transient flux linkage to generate rotor compensation voltage to suppress overcurrent and electromagnetic torque impact; and performing differential correction based on the updated inertia and damping during the fault recovery phase to suppress active power and frequency oscillations, while simultaneously controlling the energy storage system to output reactive power support and active power support based on voltage and frequency deviations. The energy storage system is a hybrid energy storage system composed of lithium batteries and supercapacitors. This invention adopts a unified virtual synchronous generator control structure, eliminating the need for control mode switching and additional hardware, and effectively suppressing rotor overcurrent and low-frequency oscillations.

The utility model relates to mahjong machine field discloses push and lift tile device and automatic mahjong machine, including frame, install the tile board that lifts, driver and the carousel with the push tile head on the frame, and driver drives the swing of lift tile board and drives carousel rotation push tile, still install the sliding block and the swing bar on the frame, the cam is installed to the one end of sliding block, and driver drives the rotation of cam through gear transmission, and the cam drives the linear motion of sliding block on the frame, the other end of sliding block is connected with swing bar and drives its swing, and the swing bar swings and drives the lift of tile board, through single driver, carousel rotation push tile and lift tile board swing lift can be realized simultaneously, need not additionally add power component, reduce the number of power source, reduce the hardware cost and assembly complexity of overall device, avoid the cumbersome problem of multiple power source coordination control simultaneously, make power output more concentrated and efficient.

This invention relates to a fluid velocity and flow rate detection device, and pertains to the field of fluid detection technology. The device includes: a fixed small steel plate and an elastic sensing unit; both the fixed small steel plate and the elastic sensing unit are disposed inside the fluid pipe to be detected; wherein, the lower end of the fixed small steel plate is fixedly connected to the inner wall of the fluid pipe, and a fixing part is provided at its upper end; the elastic sensing unit includes at least two elastic steel plates, one end of each elastic steel plate converging and connecting to the fixing part, and the elastic steel plates are radially distributed with the fixing part as the center; a first sensor is assembled at the other end of each elastic steel plate. This invention has a wide range of applicable media, strong anti-interference ability, and stable detection.

This invention relates to the field of communication technology, specifically to a collision detection method and related equipment for ultra-short-range shared medium networks. The method includes: a master node broadcasting downlink messages on a downlink channel, and slave nodes sending uplink messages within a shared uplink contention window; each slave node starting an acknowledgment response timer for each sent uplink message and waiting to receive an acknowledgment message from the master node; the master node performing frame check sequence verification on the received uplink messages, and if a verification error is found, sending a verification error alarm message to the slave node at the corresponding source address; the slave node determining a serious collision when the acknowledgment response timer expires, or determining a collision event when it receives a verification error alarm message; and the slave node executing a backoff strategy based on the collision detection results. This invention enables efficient and reliable collision detection without adding additional hardware receivers, reducing system costs and design complexity, and is suitable for ultra-short-range scenarios such as intra-robot communication.

The embodiment of the invention provides a data processing method and device, a storage medium and electronic equipment, and relates to the technical field of computers, and the method comprises the steps that a transmitting end obtains first I2S audio data, carries out the inter-frame splitting of the first I2S audio data, and obtains at least one first I2S data frame; encoding each first I2S data frame by using a Hamming code encoder to obtain an encoded second I2S data frame; the Hamming code encoder is used for encoding 4-bit data code words into 7-bit data code words, and data encoded by the Hamming code encoder is used for supporting error detection and error correction of the data; performing recombination according to the encoded second I2S data frame to obtain second I2S audio data; and sending the second I2S audio data to a receiving end based on an I2S protocol. Therefore, by grouping the frames and adopting (7, 4) Hamming codes for coding, the error correction capability is improved under the condition of increasing the minimum error correction bits, the reliable transmission of the I2S audio data is realized, and the hardware complexity is reduced.

The invention discloses smoke detector interface equipment compatible with multiple protocols. The interface device comprises a plurality of interface terminals, a protocol and interface conversion module, a switching assembly and a detection module. The plurality of interface terminals at least comprise a first interface terminal group for a first communication mode and a second interface terminal group for a second communication mode; and the protocol and interface conversion module is used for performing data interaction with an upper computer or a control host, and analyzing and converting data according to a plurality of preset communication protocols. And the switching assembly is arranged between the plurality of interface terminals and the protocol and interface conversion module, comprises a switching device with a common end and a normally open / normally closed end, and is used for switching an electric connection path between the first communication mode and the second communication mode. And the detection module is electrically connected with the plurality of interface terminals, and is used for sending a detection signal to the currently accessed smoke detector, detecting an interface type and / or a protocol type of the current smoke detector based on a feedback signal, and outputting a switching control signal to the switching assembly according to a detection result to realize automatic switching of interface channels. According to the invention, the smoke detectors with various interface forms and various communication protocols can be docked in the same equipment, automatic identification and adaptation of the interfaces and the protocols are realized, repeated development of hardware and software is reduced, field configuration is simplified, and universality and use flexibility of the system are improved.

The invention discloses a delay search method and system for a delay phase-locked loop, a computer and a medium, and the method comprises the following steps: enabling a signal to activate a finite-state machine, and jumping to a search state; based on the preset configuration of the finite-state machine, linear step length search is carried out in the guard band range to locate a target phase, if the target phase is not found in the guard band range, linear step length search is carried out again after the guard band range is expanded, and when the real-time phase is equal to the target phase, a symbol state is entered; in the symbol state, the slope of real-time phase change is calculated, and symbol matching is verified; and if the symbols are matched, entering a phase-locked state, fixing a real-time delay change value in the phase-locked state, and pulling up a phase-locked loop activation signal. According to the invention, the digital code which is output by the phase discriminator and represents the phase relationship between the reference clock and the input clock can be received, the delay is searched in a linear search mode, the control signal is sent to the delay line, and the clock delay is changed until the clock meeting the requirement is generated.

The utility model discloses a kind of continuously pressurized stable liquid supply systems, comprising: chemical distribution module is connected with external nitrogen pipeline, the output of the chemical distribution module is communicated with control box, the output of the control box is communicated with valve group box, the output of the valve group box is communicated with process machine platform;The chemical distribution module includes pressure sensor and PLC module, the pressure sensor is located at the output of chemical distribution module;The pressure sensor is electrically connected with PLC module.Beneficial effect: improve liquid supply precision, by real-time monitoring the pressure of chemical distribution module chemical distribution module outlet, and according to pressure change automatic control start-stop of liquid supply pump, effectively keep system pressure stable in set range, to realize the accurate supply of chemical, meet the high-precision requirement of chemical consumption control in production process.

The invention discloses a foot end slip detection and compensation method for a six-wheeled composite robot, and relates to the technical field of anti-slip of robot movement. The method mainly comprises the three steps that firstly, a sliding detection model is built based on a long short-term memory (LSTM) network model, and the model predicts the sliding amount of each foot end only by taking error information of an actual motion state and an expected state of a fuselage as input; secondly, according to the predicted slip amount, obtaining an instantaneous steering center and a compensation rotation angle generated by slipping of the robot through geometric calculation; and finally, according to the calculated steering parameters, the robot is controlled to execute pure rolling steering motion, a supporting polygon is reconfigured through the strategy that the non-slipping swing legs fall down and the slipping legs are lifted up, and motion errors are compensated in real time. The method has the beneficial effects that the hardware cost is low, the system is light in weight, the real-time performance and the self-adaptability are high, and the motion stability of the robot on the complex terrain can be effectively improved.

This invention relates to the field of heat dissipation, and discloses a computing system and electronic equipment, including: a housing with at least two enclosures inside, each enclosure containing an immersion medium; electrical connectors on the enclosure walls and electrical components immersed in the immersion medium inside the enclosures, the electrical components being electrically connected to the electrical connectors; a power supply module located outside the enclosures and electrically connected to the electrical connectors of each enclosure, the power supply module supplying power to the electrical components; and a fluid supply / return component located outside the enclosures and detachably connected to the enclosures, used to provide the immersion medium to the enclosures or to return the immersion medium, the power supply module and the fluid supply / return component being in thermally conductive contact. By separating the electrical components into multiple enclosures, independent maintenance is achieved without draining the fluid; the externally located power supply module and thermally coupled fluid supply / return component avoid heat accumulation, improve heat dissipation accuracy, eliminate the need for additional heat dissipation structures, simplify design, reduce costs, and enable independent operation and maintenance of the power supply and computing units, thereby improving maintenance efficiency.

The invention provides a dual-optical-path fire smoke detection smoke chamber optimization system and method, and relates to the technical field of fire detection. The method specifically comprises the following steps: synchronously acquiring light intensity signals of a main light path and an auxiliary light path, calculating an instantaneous ratio and a change rate of the main light path, and inputting into a weight analyzer to obtain a weight coefficient so as to generate a comprehensive light intensity signal; and extracting time sequence features based on the second time window, and outputting a fire probability and a confidence coefficient in combination with a pre-trained fire analysis model so as to optimize an alarm threshold value of the dual-optical-path fire smoke detection system. According to the invention, the fusion weight of the dual-optical-path signal can be dynamically adjusted, a virtual adjustable scattering angle is designed at the algorithm level, and the fire alarm fixed threshold is dynamically adjusted by comprehensively analyzing the fire probability and the detection confidence coefficient, so that the detection sensitivity of the system to different smog and the anti-interference capability in a complex environment are improved, and the system has high practicability. And meanwhile, the false alarm probability is effectively reduced.

The application discloses an adaptive path planning and pollution plume tracking method for underway monitoring, and comprises the following steps: a space model of a monitoring area is established by acquiring pose information, motion constraints and a sensor sampling period of a mobile measurement platform; pollution concentration and position information are collected in real time during platform travel to form observation data; a level set evolution method is used to construct and update a boundary representation of a pollution plume based on the observation data to depict the spatial variation of the plume; in combination with the boundary variation information, a rolling time domain optimization algorithm is used to generate a measurement path in a rolling update time range to guide adaptive adjustment of a travel route of the platform; the underway monitoring is completed by executing the path, and boundary tracking results of the pollution plume and corresponding spatial position determination results of pollution sources are output. The application is suitable for mobile monitoring and positioning tasks in complex environments.

Methods and apparatuses for wireless communications are disclosed. The first node transmits a first message, the first message indicating a plurality of measurement configurations, the plurality of measurement configurations all being available or all being unavailable. The above method reduces signaling overhead and latency, reduces hardware complexity and cost required for AI / ML, and improves overall system performance.

The invention discloses an automobile acousto-optic touch integrated controller hardware device, which relates to the technical field of an integrated hardware controller of an intelligent cabin system, and comprises an MCU (Microprogrammed Control Unit), the MCU is connected with the control signal input end of each functional module through a special control pin to realize accurate control instruction sending and state monitoring signal receiving of different functional modules, and the MCU is connected with the control signal input end of each functional module through a special control pin; the working time sequence and data interaction among the modules can be efficiently coordinated; the atmosphere lamp adjusting module is electrically connected with a corresponding port on the MCU, and the atmosphere lamp adjusting module supports three communication control modes of a CAN (Controller Area Network), an LIN (Local Interconnect Network) and a UART-CAN; core hardware circuits required by headrest sound drive, seat massage control and vehicle atmosphere light adjustment are highly integrated, visual, auditory and tactile control in the vehicle driving process is covered, and compared with a traditional distributed controller, a large amount of circuit board space occupation and connecting wiring harnesses are reduced, and the cost is reduced. And the hardware cost and the wiring complexity of the whole vehicle are reduced.

The invention relates to the technical field of image processing, and particularly discloses a charging cover pose detection method based on machine vision and a storage medium, and the method comprises the steps: employing a monocular camera to respectively shoot pictures of a charging cover which is not marked with laser rays and a charging cover which is marked with laser rays, and recording the pictures as a first image and a second image; extracting laser rays according to the first image and the second image, and extracting at least three edge feature points of the charging cover from the laser rays; calculating a feature point cloud according to each edge feature point; matching the feature point cloud with a pre-obtained target point cloud to obtain a corresponding homogeneous transformation matrix; and determining pose parameters of the charging cover according to the homogeneous transformation matrix. According to the invention, active detection of the pose of the charging cover is realized by adopting a monocular camera and laser line marking mode, and meanwhile, the method has the core advantages of low cost, low hardware complexity and ambient light interference resistance.

The invention relates to the technical field of computers, and provides a speed limit processing method, a speed limit processing device, a computer readable storage medium and electronic equipment, and the speed limit processing method comprises the following steps: receiving a network message; determining a diversion processing strategy for the network message according to the indication identifier associated with the network message; the diversion processing strategy comprises cross-cluster diversion and intra-cluster diversion; when the flow guide processing strategy is cross-cluster flow guide or intra-cluster flow guide, determining a target gateway node having a unique mapping relationship with a bandwidth packet identifier of the network message, and guiding the network message to the target gateway node; and executing bandwidth speed limiting processing on the network message through the target gateway node. According to the invention, centralized speed-limiting processing of packet traffic of the same bandwidth can be realized, and consistency, accuracy and high performance of a speed-limiting strategy are effectively guaranteed.

This invention discloses a method, apparatus, and system for tilt attitude calibration of a vertical hydrophone array based on the ray-mapping method. The method includes: sequentially performing a pre-search estimation of the receiving-transmitting distance of each hydrophone in order from shallow to deep depth, minimizing the error between the theoretically calculated arrival time difference between the direct wave and the reflected wave from the sea surface and the actual extracted time difference, thereby obtaining the optimal distance estimate for each hydrophone in the pre-search stage; recalculating the optimal direct wave arrival time for each hydrophone using the optimal distance estimate obtained from the pre-search; and again, sequentially fine-tuning and optimizing the receiving-transmitting distance of each hydrophone in order from shallow to deep depth, iteratively searching for the distance estimate that most closely matches the theoretical direct wave arrival time calculated based on the pre-search estimate with the actual measured value. This invention provides a marine vertical receiving array attitude calibration scheme that is independent of external assistance, highly accurate, robust, and computationally efficient.

This invention discloses a blood pressure monitoring method and system based on a single-channel composite signal. The method includes acquiring a time-series composite electrical signal output from a single differential acquisition channel, and performing preprocessing including power frequency suppression, baseline drift correction, and bandwidth limiting to obtain a composite waveform of electrocardiogram (ECG) and pulse wave. Further, by locating ECG and pulse wave feature points beat by beat, the method obtains the beat-by-beat pulse arrival time and pulse wave morphology features within the same beat cycle. These features are then input into a blood pressure estimation model for blood pressure parameter estimation. The blood pressure estimation model is either a mapping function constructed based on a baseline blood pressure parameter and the beat-by-beat pulse arrival time within the same beat cycle, or a data-driven model using the beat-by-beat pulse arrival time and pulse wave morphology features within the same beat cycle as input features and the baseline blood pressure parameter as the target feature. This invention can eliminate multi-channel time alignment errors and achieve non-invasive, continuous, stable, and accurate blood pressure monitoring for a single individual.

The invention relates to the technical field of intelligent service and automatic control, and discloses a winter Austrian unmanned selling vehicle and a control system thereof, and the winter Austrian unmanned selling vehicle comprises a mobile device, a commodity storage and selling device, a sensor interaction module and a central controller. The moving device is provided with a first driving motor and a second driving motor in a rigid fixed connection mode, and a low-attenuation mechanical vibration transmission path is constructed. The sensor time division multiplexing control module maps the signal of the multiplexing type touch assembly into a collision braking instruction or a delivery starting instruction according to the global state variable. And the collaborative anti-jamming recovery module controls the first driving motor and the second driving motor to execute high-frequency positive and negative rotation pulse actions during shipment jamming, and the alternating inertia moment is used for assisting in getting out of the jamming. And the load adaptive cruise module dynamically adjusts the basic cruise power according to the stock quantity change. The power of the moving device is used for solving the material blocking fault, hardware reuse is achieved, and slipping on the ice and snow covered pavement is effectively prevented.

This invention discloses a temperature-adaptive heating method and system for lithium-ion batteries at low temperatures. The method selects between off-grid and grid-connected heating modes based on the lithium-ion battery state: In off-grid mode, the power devices inside the energy storage converter, along with the AC-side filter inductor, filter capacitor, and battery cluster units, are reconstructed into a closed internal resonant heating circuit. AC heating current is generated by periodically switching the power devices on and off to excite resonance. In grid-connected mode, the energy storage converter is controlled to periodically switch between rectification and inversion states to generate AC heating current. The method also involves three-phase bridge arm drive control and dynamic switching, battery cluster group heating, lithium plating prevention protection based on calibration tables and lithium plating indicators, bias current regulation, and DC support capacitor switching. This invention reuses existing hardware of the energy storage converter to achieve dual-mode adaptive heating without requiring additional power equipment, balancing heating efficiency and battery safety.

The application discloses a kind of pressure estimation methods of air pressure brake system based on data and physical fusion model, the method is collected air source pressure, brake chamber pressure and ABS solenoid valve control instruction by test bench, constructs time sequence sliding window sample and normalizes processing;Physical information neural network model containing long short-term memory network and full connection layer is constructed, its output brake chamber pressure estimation value, brake chamber temperature, the gas mass flow of valve port and chamber volume are calculated;According to the differential equation of pressure change rate, the physical law residual is calculated;In training, data fitting loss and physical residual loss jointly constitute total loss function, and network parameters are iteratively updated using Adam optimizer until the model converges;The trained model is deployed in brake system controller, brake chamber pressure can be estimated with high precision, strong robustness and physical consistency online only according to air source pressure and valve instruction.

The application discloses a laser calibration method and device, which is applied to the technical field of laser processing and comprises the following steps: projecting a laser beam on a calibration plate according to a preset circular array calibration pattern through an electric laser galvanometer unit, so as to generate a calibration pattern on the calibration plate and record a galvanometer coordinate set corresponding to each feature point in the calibration pattern; collecting the calibration pattern generated on the calibration plate to obtain a calibration image; processing the calibration image to extract an image coordinate set corresponding to each feature point in the calibration image; constructing a transformation matrix between the galvanometer coordinate set and the image coordinate set; and converting the coordinates in the galvanometer coordinate system into corresponding coordinates in the image coordinate system based on the transformation matrix, so as to complete laser calibration. The application solves the transformation matrix by acquiring the calibration pattern and extracting the center feature point, and the calibration of the galvanometer and the image coordinate system can be completed without the aid of external standard calibration equipment, so that the operation process is effectively simplified and the hardware cost is reduced.

The present application relates to the technical field of action control, in particular to a continuous action control method and system based on fork loading and unloading, the present application realizes adaptive identification of cargo unloading event by collecting torque feedback of lifting driving mechanism and performing differential analysis, and latches actual unloading fork position; based on the position, middle position and target loading position, a complete motion path is constructed, and two-stage stroke compatibility determination of fork retraction and extension is performed to determine whether continuous action is enabled; during continuous action, fork extension and walking shaft motion are scheduled in parallel, and subsequent fork extension action is triggered through state flag synchronization mechanism; at the same time, motion parameter is used to predict loading completion time and send pre-notification message; in abnormal conditions, a cancellation message is sent and a safety rollback is performed. The present application can effectively improve the continuity, efficiency and safety of fork operation in automatic warehouse system.

This invention relates to the field of on-orbit telescope setup and adjustment technology, specifically providing a method for inverting the offset of an optical system using point spread function patterns. The method includes the following steps: constructing an optical model of the optical system to be set up and adjusted; applying a preset offset; acquiring corresponding star patterns in multiple preset fields of view; labeling the corresponding offset and field of view on each star pattern; and constructing a training dataset. A setup and adjustment prediction network based on a generative adversarial network for auxiliary classification is established, and the network is trained using the training dataset. The trained network is then used to estimate the offset and perform system correction on the optical system to be set up and adjusted. This invention eliminates the need for additional wavefront sensors, directly inverting active correction values ​​using star patterns acquired by an on-orbit camera.

The invention relates to a manipulator multi-mode tactile perception and object recognition system and method, and the system comprises a manipulator actuator, a multi-channel flexible tactile sensor array, a signal collection module, and a processing terminal. Wherein a flexible tactile sensor in the multi-channel flexible tactile sensor array comprises a packaging layer, an electrode layer, a conductive sensitive layer and an elastomer layer, and the multi-channel flexible tactile sensor array is in contact with a target object; a microstructure array is arranged on one side, facing the conductive sensitive layer, of the packaging layer and / or the elastomer layer, and the microstructure array and the conductive sensitive layer form an interlocking / embedding interface. Compared with the prior art, the method has the advantages that the recognition robustness under the complex surface condition is improved, the weight prediction error is reduced and the like.

This invention discloses a method and system for Wi-Fi backscatter covert communication utilizing the FCS (Focus Cross Section) characteristic, belonging to the field of wireless communication. The implementation method of this invention is as follows: the transmitting tag encodes covert information into location information, and based on the location information containing the covert information encoding, generates an intentional error during the backscattering of the Wi-Fi signal. After demodulating the Wi-Fi backscattered signal, the receiving end uses the FCS characteristic to determine the location of the intentional error, and demodulates the covert information according to the covert information encoding, thus realizing Wi-Fi backscatter covert communication using the FCS characteristic. By encoding the covert information into intentional error location information at the transmitting end, the amount of covert information carried in the Wi-Fi data packet containing the covert information is increased, thereby improving the throughput of covert communication. This invention also discloses a system for implementing the aforementioned method for Wi-Fi backscatter covert communication utilizing the FCS characteristic.

This invention discloses a radar error calibration method and system based on a vision transformer, belonging to the field of radar data processing and error calibration technology. The method includes: acquiring radar measurement data and AIS data as ground truth; transforming the geographic coordinates of the AIS data to a local Cartesian coordinate system centered on the radar position, and achieving time alignment with the radar measurement time through linear interpolation; calculating the range error sequence and azimuth error sequence based on the aligned data, and weighting the results with confidence levels by combining AIS position accuracy information and ship navigation status information; constructing a radar error calibration model based on a vision transformer architecture; using the trained radar error calibration model to predict errors in the radar data to be calibrated, and completing the calibration. This invention can effectively characterize the long-range dependence and nonlinear relationship in radar errors, improve the accuracy of radar ranging and direction finding error calibration, and has good generalization ability and interpretability.

The invention relates to the technical field of digital integrated circuit design, and discloses an on-chip network communication architecture system in a noise environment, which integrates two sets of independent ARQ and HARQ systems optimized aiming at different data bit widths at the same time, utilizes the characteristics of on-chip network wormhole exchange and sequential microchip transmission of a virtual channel, and improves the communication performance of the on-chip network. And a set of sequential storage and address-corresponding unified management strategy is designed. The sending buffer area and the receiving buffer area are consistent in depth and are in one-to-one correspondence in address, so that complex out-of-order management and sorting logic are eliminated fundamentally, the effect of'controlling complexity with simplicity 'is realized, and excellent balance among reliability, performance and hardware overhead can be realized in a network-on-chip in a high-noise environment.

The utility model relates to the field of paint stripping device, especially single laser overturning paint stripping device. Including jig, laser assembly and shift loading component, wherein, the jig has the loading end for loading material, and makes the material on the loading end parallel to the exposure of at least three planes of first direction, the laser assembly includes single laser, the laser has the emission end corresponding the loading end. Shift loading component is connected with the jig and can drive the jig to move along the first direction and overturn around the first axis of a level setting parallel to the first direction, so that the first surface, second surface, third surface on the material correspond the emission end of laser assembly in proper order. The device drives the jig to overturn accurately around the first axis through the overturning mechanism, so that single laser can cover three parallel surfaces of material in proper order, and the hardware cost and maintenance complexity are reduced obviously. The coaxial drive design of overturning mechanism ensures that the jig overturning angle is accurate and stable.