基于DSP的四旋翼无人飞行器控制系统

本文以四旋翼飞行器为研究对象,以TMS320F28335为核心,搭建飞行器硬件平台,实现四旋翼飞行器的姿态控制。详细介绍了控制系统硬件设计方法,采用基于RBF神经网络整定的PID控制策略,最终实现了飞行器的垂直起降、稳定悬停和便携设备超远程控制。     

STM32嵌入式平台下四旋翼飞行器模型研究

针对四旋翼飞行器一键启动、自主飞行、高空悬停及距离预警等问题,提出了四旋翼自主飞行器探测跟踪系统模型,通过比例-积分-微分控制器(Proportion Integral Derivative,PID)算法实现飞行器距离地面1 m自主飞行悬停,感应小车发出预警灯光指示等要求。该系统采用STM32控制芯片,以压力传感器、陀螺仪等辅助保持平。通过多次飞行实验验证,本系统方案拥有可行性高、简单、易操作和成本低多个特点。     

四旋翼飞行器建模及姿态稳定性分析

主要讨论了四旋翼飞行器的姿态稳定性。经过适当假设和部分简化建立了悬停姿态动力学模型,对悬停姿态模型进行了仿真分析,在开环控制的前提下分析了结构增稳和橡筋阻尼方法对飞行器平台姿态稳定性的影响,并提出了一种开环控制下实现稳定悬停的策略。     

基于滑模控制的四旋翼飞行器控制器设计

基于四旋翼飞行器的结构和飞行原理,本文建立了其飞行动力学数学模型,并采用反馈线性化原理对该模型进行精确线性化;同时,本文采用基于趋近律的滑模变结构控制方法,进行飞行控制器设计,并用simulink对设计的控制器进行仿真,实现了四旋翼飞行器的定高悬停控制,提高了其飞行性能和鲁棒性。     

基于LPC1752的四旋翼飞行器控制系统设计

四旋翼飞行器具有结构简单,质量轻,易于控制,能够垂直起降和自由悬停等优点。本文以LPC1752作为控制核心,对四旋翼飞行器控制系统进行研究和设计,硬件设计主要包括无线通信、传感器模块和电机驱动。软件设计主要完成对各个模块的控制以及数据的采集和处理。     

基于AVR单片机的四旋翼飞行器的设计

四旋翼飞行器具有机械结构简单、成本低、事故率低、重量轻等优点,因此应用前景广泛。文章以Arduino Mega2560单片机为核心控制器设计一架小型四旋翼飞行器。首先,通过主控制器、惯性测量单元、遥控通信模块、电源与驱动模块完成系统的硬件结构设计。其次,采用卡尔曼滤波来消除干扰,以及利用四元数算法解算出飞行姿态角控制电机的转速,并通过双闭环串级PID控制来调节飞行器的平衡性。最后采用C语言编写控制程序,软硬件联机调试并进行实地飞行测试。测试结果证明,四旋翼飞行器可以很好地平稳起飞,并且可以完成自稳、悬停等运作,达到了设计目的。     

变桨距四旋翼飞行器的建模与控制研究

变桨距四旋翼飞行器可以通过改变4个旋翼的桨距大小来控制对应旋翼的拉力,从而调节四旋翼飞行器的姿态和位置。四旋翼飞行器的桨距调节控制策略相比传统的单一转速调节对于提高自身运动的机动性及可靠性具有重要意义,未来在微型飞行器的编队飞行、精确任务方面应用前景广阔。为了分析变桨距四旋翼飞行器大角度非线性运动的控制可实现性,采用欧拉法对其建立了非线性动力学模型,并将反馈线性化的非线性控制方法应用于所建立的飞行器模型。最后,结合Simulink软件对非线性控制下四旋翼运动过程的仿真,探讨了非线性控制理论对四旋翼飞行器运动的控制作用,为变桨距四旋翼飞行器大角度非线性运动的控制实现提供参考。     

基于四旋翼飞行器的改进金字塔LK光流算法的研究

针对四旋翼飞行器在飞行过程的水平漂移问题,提出利用改进的金字塔LK光流算法予以改善.首先,通过VisualStudio2013仿真,确知改进的金字塔LK光流算法比传统金字塔LK光流算法对图像的速度信息提取精度更高.然后,再建立四旋翼飞行器的动力学模型,将两种光流算法导入MATLAB的仿真模型中,得出:四旋翼飞行器能有效根据改进的金字塔LK光流算法获得速度信息以降低水平漂移.最后,通过在轴距为430 mm的四旋翼飞行器的平台上进行飞行试验,结果表明:采用改进的金字塔LK光流算法能使四旋翼飞行器的水平漂移程度降低,可实现较为稳定的悬停.     

Kinect人机交互入门（2）体感直升飞机的制作

很早的时候我就在做飞机的体感控制，最开始做的是四旋翼飞机，后来因为四旋翼飞机飞行的稳定性、安全和成本等诸多问题，我放弃了四旋翼方案。直升飞机相对于四旋翼飞机的最大优点就是更容易在空中悬停，这对于体感控制来说很关键，更便于测试。四旋翼飞机不是不可以悬停，只是成本太高，控制难度也要明显高于直升飞机。这一期我带领大家分析和制作体感直升飞机。     

四旋翼无人机仿真控制系统设计

为了实现四旋翼无人机的自稳定控制,对四旋翼无人机进行了动力学建模与控制。在建模时利用机理建模和实验实测相结合的方法,建立小型四旋翼飞行器的动力学仿真模型;并通过准LPV法将非线性模型线性化,在飞行器模型解耦的4个通道上分别设计PID控制器,且在Matlab/Simulink平台上对系统整体进行仿真。仿真结果表明,该动力学模型和PID控制器可以有效地实现飞行器的自稳定控制,为后续的四旋翼飞行器的控制研究打下基础。     

A monolithic ±5 1/2-digit BiMOS A/D converter

A monolithic ±5-1/2-digit BiMOS analog-digital converter that achieves integral integrity within two counts over the range -2 V to +2 V and noise error for any single reading within ±1 count is described. The part uses four noncritical external passive components; the reference voltage is also provided externally. The converter uses a three-pass algorithm with a modified dual-slope integration and subsequent residue multiplication steps. It has been integrated on a BiMOS process based on a production 4-μm CMOS process with one mask added and the starting material polarity changed     

四轴飞行器控制系统设计与实现

设计了一种基于捷连贯性导航的四轴飞行器控制策略,采用串级PID控制方法,在惯性导航学的基础上,综合比较了在运用互补滤波和卡尔曼滤波融合算法情况下飞行器的平衡效果和动态响应性能.实验结果表明运用互补滤波的串级PID平衡控制策略能够较好的控制四轴飞行器的平衡性,有较强的鲁棒性和抗干扰性.     

Precision positioning device utilizing impact force of combinedpiezo-pneumatic actuator

This paper reports on a new actuator combining both a piezoelectric actuator and pneumatic cylinder for the automatic assembly application. The results of fundamental experiments are presented and an analytical model is described. The experimental results show that the proposed actuator can move a target object with step sizes in the 10-nm order by utilizing the impact force of a piezoelectric element while maintaining the comparatively long operation range of a pneumatic cylinder. Furthermore, a 3-DOF positioning system had been constructed as a practical application. Due to the limited sensing range of the gap sensors, the positioning range is limited to ±1 mm, ±1 mm, and ±2 mrad along the 3-DOF. A heuristic control model is described. Using this model, a target object made of stainless steel (130×100×10 mm) was successfully positioned with an accuracy of ±0.5 μm, ±0.5 μm, and ±20 μrad along the 3-DOF. It is shown that the combined piezo-pneumatic actuator has attractive practical applications in the field of precision industry     

A low-power CMOS time-to-digital converter

A time-to-digital converter, TDC, with 780 ps lsb and 10-μs input range has been integrated in a 1.2-μm CMOS technology. The circuit is based on the interpolation time interval measurement principle and contains an amplitude regulated crystal oscillator, a counter, two pulse-shrinking delay lines, and a delay-locked loop for stabilization of the delay. The TDC is designed for a portable, low-power laser range-finding device. The supply voltage is 5±0.5 V, and the operating temperature range is -40 to +60°C. Single-shot accuracy is 3 ns and accuracy after averaging is ±120 ps with input time intervals 5-500 ns. In the total input range of 10 μs, the final accuracy after averaging is ±200 ps. Current consumption is 3 mA, and the chip size is 2.9 mm×2.5 mm     

Optical fiber drawing method with gas flow controlling system

A method for reducing the diameter variation of optical fibers during fiber drawing is described. The method is based on the control of gas flow and drawing speed. Rapid fluctuations in diameter are suppressed by adjusting the gas flow rate, and slower ones are controlled by changing the drawing speed. The efficiency of this method has been tested by applying stepwise disturbance of ±63% in preform feeding speed. Fluctuations of fiber diameter are controlled within ±1 μm despite the forced disturbance. By applying this method to high-speed drawing (30 m/min), a high-tensile-strength fiber, with diameter fluctuations within ±1 μm and transmission losses near the 0.85-μm wavelength region of approximately 3 dB/km, is achieved     

RELEDOP: a full-scale antenna pattern measurement system forhigh-powered HF transmitting antennas

A system is presented that utilizes a towed, 3-axis receiver called RELEDOP. RELEDOP is a receiving elementary dipole with optional polarization that measures the transmit directivity patterns of over-the-horizon backscatter (OTH-B) radars and shortwave broadcast transmitting arrays. A dielectric tow cable and a fiber-optic link to the towing aircraft permit excellent electromagnetic isolation of the RELEDOP sensor from the aircraft. High accuracy in position location (±15 m in x, y, and z) and fast-receiver sampling permit orthogonal polarization component measurements with accuracies of ±0.15° in bearing and ±1 dB in relative amplitude. Calibrated receiving element gains permit measurement of absolute field strength. The field strength data, combined with the position data, permit an assessment of transmitter effective radiated power (ERP); a knowledge of input power permits a computation of absolute gain of the transmitting antenna to ±3 dB or better. The RELEDOP system is described, along with its subsystems; towed sensor, airborne, positioning, ground station, and communications subsystems. Example patterns and flight path tracks illustrate the output graphics     

Active GaAs MMIC band-pass filters with automatic frequency tuningand insertion loss control

This paper presents the design and measured performance of active tunable band-pass MMIC filters and matched MMIC control circuits, both fabricated using a standard 1-μm GaAs MESFET foundry process. The control circuits generate filter frequency-tuning and Q-control bias voltages by using a dual-loop master-slave control scheme. Separate 3-section filters cover 1.5-2.0 and 1.96-2.64-GHz bands with 3-dB bandwidths of 86±6 and 126±1.0 MHz, respectively. The control circuits automatically maintain the filter insertion loss to within ±0.5 dB over these tuning ranges, and regulate the center frequency and insertion loss to within better than ±1.2 MHz and ±0.3 dB over a temperature range of -50°C to +75°C     

Video-frequency current-voltage mode integrator

A continuous time integrator based on both current and voltage mode processing is presented for applications over the video frequency range. Using a very low-cost 2.4 μm CMOS process, the integrator consumes less than 2.5 mW from a ±1.5 V supply. Experimental results show a tunable unity-gain range from 4.5 to 12 MHz with a 58 dB dynamic range     

An integrated time-to-digital converter with 30-ps single-shotprecision

A time-to-digital converter (TDC) with 32-ps resolution and 2.5-μs measurement range has been integrated in a 0.8-μm BiCMOS process. The TDC is based on a counter with a 100-MHz clock. Two separate time digitizers improve the time resolution by interpolating within the clock period. These interpolators are based on analog dual-slope conversion. According to test results, the single-shot precision of the TDC is better than 30 ps (σ-value) and the nonlinearity is less than ±5 ps when input time intervals range from 10 ns to 2.5 μs. The conversion time is ⩽6.3 μs. Temperature drift, excluding the temperature dependence of the oscillator, is below ±40 ps in the temperature range of -40 to 60°C. The size of this chip, including pads, is 3.5×3.4 mm² and its power consumption is 350 mW     

A 45-Mbit/s CMOS VLSI digital phase aligner

An eight-channel, 45-Mb/s digital phase aligner (DPA) has been fabricated in 2-μm CMOS. The device receives asynchronous serial data at a known average clock frequency and unknown phase, and phase-aligns it with a local clock of the same frequency for subsequent synchronous processing. The all-digital architecture of this device minimizes the need for external components and avoids reliance on analog MOS circuitry. Tracking over a phase excursion range of ±4-bit periods has been demonstrated