5results about How to "Compensation drift" patented technology

The invention discloses a spacecraft ground full-physical simulation system attitude measurement calibration method and device, and belongs to the technical field of spacecraft measurement. The objective of the invention is to solve the problem of real-time measurement of the attitude of a spacecraft ground full-physical simulation system. A cross laser generator, a concentric circular ring coding target, a monocular camera and a processing unit are fixedly installed on a three-axis air bearing table, the monocular camera is fixedly arranged on one side of the cross laser generator, and the monocular camera is connected with the processing unit. Laser emitted by the cross laser generator vertically irradiates the plane of the concentric circular ring coding target, the concentric circular ring coding target adopts a concentric circular ring coding array design, and each group of concentric circular ring coding units is composed of a plurality of hollow circular rings which are concentrically arranged. And generating a code ID of each group of concentric circular ring coding units through radius proportion combination of the adjacent hollow circular rings. The method is stable in long-term operation precision, greatly reduces the workload of element installation and calibration, does not need a complex field calibration process, and is flexible in installation and deployment.

This invention belongs to the field of time measurement technology and discloses a resource-saving short-chain time-to-digital converter and its conversion method. It utilizes a delay unit and conversion circuit to build a local oscillator, which flips the output state at fixed time intervals during a continuous high-level input signal. The time at which the local oscillator causes the level to flip is known. The time of the last flip is obtained using TDL and TDC, and the start and last flip times are obtained by recording the number of flips of the local oscillator. The resource-saving short-chain time-to-digital converter provided by this invention has good linearity, completely avoiding nonlinearity problems caused by inconsistent line lengths introduced across multiple resource blocks. The resource-saving short-chain time-to-digital converter has a simple and flexible structure, low resource consumption, and high utilization rate. It has good robustness and can be directly ported between different channels or even devices, and can correct temperature-induced drift online.

This utility model relates to the field of machining technology, and in particular to a positioning mold for opening holes in automotive reflectors. It includes a main mold plate and an electronic level fixed horizontally on the main mold plate. The main mold plate has openings adapted to the position of the headlight mounting rod. The main mold plate also has a positioning post passing through a reference hole at the bottom of the reflector and coaxial with the optical axis of the reflector. A fastener is fitted onto the positioning post, passing through the bottom of the reflector and positioned between the main mold plate and the reflector. A first chuck is fitted onto the fastener to limit and fix the bottom of the reflector. A locking nut is also fitted onto the fastener to lock the reflector in place. In this utility model, through optical axis reference transmission and closed-loop control of the electronic level, the hole position can be perfectly matched with the headlight mounting rod, effectively reducing the error in the angle between the opening axis and the optical axis, and avoiding optical path misalignment caused by assembly stress.

The invention discloses a linear motor control method based on feedforward adaptation and a storage medium, and relates to the technical field of motor control. The method comprises the following steps: determining a position error based on an actual position of the linear motor and a preset reference position, and determining an acceleration error based on an actual acceleration of the linear motor and a preset reference acceleration; a feed-forward parameter change rate is determined based on a preset adaptive formula and the reference speed, the reference acceleration and the acceleration error of the linear motor, a feed-forward control parameter is determined based on the feed-forward parameter change rate, and the adaptive formula is obtained by deducing an error kinetic equation of the linear motor through a Lyapunov stability criterion; determining a feed-forward control quantity based on the feed-forward control parameter, the reference speed and the reference acceleration, determining a feedback control quantity based on the position error, and determining a total control quantity according to the feed-forward control quantity and the feedback control quantity; and driving the linear motor to move according to the total control quantity.

The invention discloses an alternating current coupling square wave open-loop demodulation and reset voltage tracking method for an all-fiber current transformer. A specific square wave modulation signal with a period containing eight non-zero phase segments is applied to a phase modulator, and synchronous segmented sampling and accumulation are carried out on an output signal of an optical detector. Based on the accumulated value of each section, an operational formula for demodulating the phase signal of the detected current is constructed, and the formula can effectively offset the influence of the input light intensity and the direct current component, so that the system can adopt an alternating current coupling amplification circuit. Meanwhile, real-time and online tracking and calibration of the modulator reset voltage are achieved by checking the equality relation between the accumulated values of the specific sections, and an independent calibration period is not needed. Compared with the prior art, the problems of large measurement error and poor stability caused by light source fluctuation and modulator parameter drift in a traditional open-loop scheme are solved, and the measurement precision and long-term operation stability of the optical current transformer are remarkably improved.