31results about How to "Avoid loss of precision" patented technology

The invention relates to a carbon dioxide content determination apparatus. The apparatus comprises a reaction device, the reaction device comprises a reaction bottle, the reaction bottle is provided with a separating funnel having a piston, an alcohol burner is arranged under the reaction bottle, a device for absorbing carbon dioxide in air is arranged in front of the reaction bottle, and an impurity removal device, a carbon dioxide absorbing device and a water absorbing device are sequentially arranged behind the reaction bottle. The apparatus has the advantages of simplicity, easy operation, realization of the assembling completion in most laboratories, and wide application range. The carbon dioxide content result determined through using the apparatus is stable and reliable, and has a good precision and a good accuracy; and simultaneously anhydrous calcium chloride is used to substitute anhydrous magnesium perchlorate, so the measure cost is effectively reduced, and the apparatus is economic and practical.

The invention discloses a control driving system for a universal rack, which can realize stable and reliable rack rotation control and high control precision. A photoelectric encoder and a potentiometer are arranged on the rack and a motor respectively, two measurement angle values are calibrated through an angle calibration module, and thus, a self-calibration function is realized; in the case of automatic control, when the rack moves near a target angle, different operating frequencies are transmitted to a frequency converter according to the difference between the current angle and the target angle, the relationship between the angle difference and a motion speed can simulate a damped motion curve, the motion speed of the rack just reaches 0 when the rack moves to the target angle, and thus, zero overshoot control is realized, and the rotation precision is high; and through detecting the position of a treatment couch in real time through an automatic anti-collision control unit and an anti-collision and anti-over turning control module, collision between the rack and the treatment couch is automatically prevented.

The invention relates to a high-accuracy rotational speed controller of a phase-locked motor. The high-accuracy rotational speed controller comprises a first counter, a second counter, a third counter, a proportion integration differentiation (PID) controller, a pulse width modulation (PWM) controller and a Hall sensor, wherein the counters are used for counting a period of an external output reference square wave signal SYN, a period of a Hall signal and current phase difference between the square wave signal SYN and the Hall signal according to a frequency CLK, the Hall period counting valuen' is subtracted from the SYN period counting value n to obtain a difference value es used as rotational speed part control quantity, reference phase difference 0 is added to the current phase difference phaseErr, phase part control quantity ep is obtained after graining k, the sum of the es and the ep is used as total control quantity e to be input to the PID controller, an output is finally obtained by the PID controller, and the motor is controlled to rotate by the PWM controller. On the basis of traditional rotational speed feedback, a phase-locked loop is additionally arranged, relatively high rotational speed accuracy of the motor is ensured, the phase of a reference signal also can be traced constantly, and the problem that an angle error rotated by the motor can become large withtime accumulation due to rotational speed deviation of a pure-rotational speed control ring is solved.

The invention discloses a fast ergodic synchronous data flow (SDF) system node parameter processing method based on graphs. The fast ergodic synchronous data flow system node parameter processing method includes that an SDF graph is built for a real-time system, communication parameters of nodes connected at two ends on the side are marked at the two ends of each side in the graph, a node needed to be temporarily stored in the SDF graph stacking and storing ergodic process is built, any one node in the SDF is selected and operation parameters of the selected node are initialized, scanning is started, whether rings exist in the graph can be judged when each node is scanned, operation parameter consistency judgment is performed on yes judgment, otherwise, the operation parameters of the node are determined on the basis of communication parameters of the node, and the operation parameters of the scanned nodes in the graph are subjected to overall normalized adjustment. The fast ergodic synchronous data flow system node parameter processing method is few in processing steps, small in calculating amount, high in efficiency and accurate in calculating result, has the universalizaion advantage of being capable of processing parameters in different attributes, and improves speed and efficiency of computers for processing real-time SDF system node operation parameters.

The present invention provides a high-precision quantitative acceleration method for ultra-high resolution image analysis, which is used to improve a large amount of intermediate data calculation process in the ultra-high resolution image analysis process through quantization, and is characterized in that it includes the following steps: Step S1, obtain the accuracy α required for the final result, and obtain the accuracy β that needs to be retained in the intermediate calculation; step S2, obtain the intermediate variable X, and perform the intermediate variable X according to the accuracy β that needs to be retained in the intermediate calculation through the current calculation system γ Quantize to get the offset variable X 1 ;Step S3, based on the offset variable X 1 Carry out the calculation operation, obtain the calculation result Y1, and reserve the calculation process queue Q in the calculation process; step S4, by the calculation result Y 1 , the accuracy β that needs to be preserved in the intermediate calculation, and the calculation process queue Q to get the final result Y of the final base.

The invention provides a method and a device for realizing an image container control with the effect of a convex lens. The method comprises the following steps of: collecting the offset delta x of x-coordinate generated by moving figures on a touch screen at intervals per unit time using the top left corner of a main window as the origin of coordinate of the main window; calculating the X coordinate Xw(i) of the origin of coordinate of a display window according to the offset of the coordinate x generated by moving figures at intervals per unit time and calculating the zoom coefficient according to the X coordinate XC in the centre point of the display window and the X coordinate X(i) in the centre point of the subcontrol; obtaining the width W(i) of a new image and the height H(i) of a new image according to the zoom coefficient; calculating coordinate X at the top left corner of the new image according to the X coordinate X(i) in the centre point of the subcontrol, the width W(i) of the new image and the X coordinate Xw(i) of the origin of coordinate of the display window; calculating the coordinate Y at the top left corner of the new image according to the Y coordinate H in the centre point of the subcontrol and the height H(i) of the new image; and drawing the image according to the parameters. The invention realizes the image container control with the effect of the convex lens in a way of light-weight resource consumption in case of limited CPU and memory resources.

The invention discloses a pipe fitting forming device, which comprises a workbench and an upper base plate arranged sequentially from top to bottom, a lifting mechanism is arranged between the workbench and the upper base plate, and the upper base plate moves up and down through the lifting mechanism; the top surface of the workbench The lower mold assembly, the lower stripping plate and the lower mold base are arranged in sequence from top to bottom; the upper mold base, the upper stripping plate and the upper mold group are arranged in sequence from top to bottom on the bottom surface of the upper base plate opposite to the top surface of the workbench pieces. Compared with the single-station, single-process processing mode, the present invention saves the time spent on re-clamping pipe fittings between processing processes, has high processing efficiency, avoids the loss of precision caused by multiple clamping, and effectively improves the processing accuracy. , fully meet the quality requirements.

The invention relates to the technical field of dynamic system optimization, and proposes a semi-analytical sensitivity analysis method for flexible multi-body system dynamics based on absolute node coordinate description. First, based on the absolute nodal coordinate method, the mass matrix, stiffness matrix and generalized force array of the flexible multi-body system are established; secondly, the dynamic equations of the flexible multi-body system and the optimization objective function are established; thirdly, based on the direct differential method or accompanying variable The semi-analytic sensitivity calculation formula of the flexible multi-body system dynamics is established by using the method; finally, the differential algebraic equation of the flexible multi-body system dynamics is solved to obtain the sensitivity calculation results. According to the absolute node coordinate method and the multi-body system dynamics theory, the present invention establishes a semi-analytical sensitivity calculation formula of the flexible multi-body system to solve the sensitivity analysis problem of the flexible multi-body system dynamics, and aims to provide a set of flexible multi-body system sensitivity A new strategy for analysis that facilitates sensitivity calculations for large-scale complex flexible multibody systems.