Lidar, the acronym of light detection and ranging, has received much attention for automotive industry as a key component high level automated driving systems due to their resolution highly accurate 3D imaging surroundings under various weather conditions. However, price lidar sensors still do not meet target values market be accepted basic sensor ensuring safe autonomous driving. Recent work focused on MEMS scanning mirrors potential solution affordable long range systems. This paper...

This article presents a novel method to derive and identify an accurate small perturbation model of comb-actuated resonant microelectromechanical system (MEMS) mirror with highly nonlinear dynamics. Besides the stiffness damping, comb-drives add nonlinearities due their electrostatic nature effect on dynamic amplitude over frequency behavior. The proposed is based period energy conservation applies for most present in oscillator such as MEMS mirrors. It shown that specific nominal operation...

This paper demonstrates a vibration test for resonant MEMS scanning system in operation to evaluate the immunity automotive lidar applications. The mirror has reinforcement structure on backside of mirror, causing coupling by mismatch between center mass and rotation axis. An analysis energy variation is proposed, showing direction dependency coupling. Vibration influences are evaluated transient response frequency sweep using single tone translational y- z- measurement results demonstrate...

Mismatch between the refractive indexes of immersion media and glass coverslips introduces spherical aberrations in microscopes especially for high numerical aperture objectives. This contribution demonstrates an automated adjustment coverslip correction collar scanning confocal microscopy to compensate due thickness mismatch. With a motorized collar, procedure consists xz image scans, processing, quality evaluation, mismatch estimation, eventually optimal collar. For fast with less...

This paper presents a receding horizon control (RHC) for an unconstrained input-delayed system. To begin with, we derive finite optimal quadratic cost function including two final weighting terms. The RHC is easily obtained by changing the initial and times of control. A linear matrix inequality (LMI) condition on matrices proposed to meet monotonicity, under which monotonically nonincreasing with time hence asymptotical stability guaranteed only if observability met. It shown through...

Accurate modeling of MOEMS mirrors is crucial for their design and fabrication, as well proper control within its target applications. This paper proposes a novel identification method using generalized nonlinear SDOF model an electrostatically actuated 1D resonant mirror solely based on measured scanning trajectories the current generated by movement comb-drive electrodes. The stiffness damping are identified from decay measurement while torque rotor inertia derived measurement, where...

Accurate phase detection and control of nonlinear resonant micro-opto-electro-mechanical system (MOEMS) mirrors are crucial to achieve stable scanning motions high resolution imaging as needed in precision applications. This paper proposes a precise method for an electrostatic actuated MOEMS mirror novel digital locked loop (PLL) that uses asynchronous logic driving immediate compensation, while the clock speed is kept low. The detected by amplified current signal, generated movement comb...

For an accurate and precise periodic scanning motion of a galvanometer scanner, this paper presents iterative learning control (ILC) that is designed implemented in the frequency domain to compensate for system nonlinearities, such as static friction. case identification advance difficult due frequency-domain ILC itself incorporates performs during learning, modeling-free inversion-based (IIC). A law derived nonlinear system, where internal formulated estimation problem Jacobian matrix...

This paper proposes a MEMS test bench to ensure highly accurate and precise angle measurements for evaluation of multiple mirrors analyzes its measurement uncertainty. The includes position sensitive detector (PSD) with motorized stage convert the beam displacement on PSD mirror by dedicated calibration procedure. Uncertainties in are analyzed considering optical alignment, characterization PSD, data. By proposed uncertainty analysis, accuracy developed shows up 0.026° at 15°.

This contribution presents charge-based capacitive self-sensing with a continuous full state observer for parametrically driven resonant electrostatic 1D MEMS mirror considering precise and seamless estimation. Based on current integrators, series capacitances or capacitance network the direct charge principles are investigated compared leakage currents, precision minimum implementation effort. In comparison to other sensing methods, proposed methods directly measure changes while drive...

An accurate analytic model of a parametrically driven resonant MEMS mirror is proposed using Fourier series based approximation for out-of-plane comb drive torque. The consists slow evolution equations the amplitude and phase derived by averaging theorem perturbation theory. Based on model, expressions primary frequencies Jacobian are derived, which computationally efficient provide additional information steady state solutions local dynamics. Measurement results frequency response show less...

This paper proposes a phase modulation method for Lissajous scanning systems, which provides adaptive scan pattern design without changing the frame rate or field of view. Based on rigorous analysis scanning, constrains and pixel calculation are derived. An accurate simple metric resolution is proposed based area spanned by neighboring pixels used optimization also considering scanner dynamics. The methods implemented using MEMS mirrors verification shaping, where 5-fold improvement in...

A transformation-based iterative learning control (ILC) approach is proposed to achieve accurate image scanning for the non-collocated dynamics of a galvanometer scanner. The non-collocation between encoder and beam mirror results in tracking error actual position although measurement matches reference signal. ILC extended from conventional design by adding transformation filter, which based on transfer functions measured controlled output. An analysis shows that method can reduce output,...

This contribution demonstrates an automated adjustment of the coverslip correction collar in scanning confocal microscopy to compensate for aberrations caused by thickness mismatch.An axial image model is derived filtering measured improve signal noise ratio.To find best alignment, 70 scans equally spaced over actuation range are recorded and evaluated automatically.The reveal that different coverslips have a shift maximum intensity optimal imaging along angle.Correction quality such as or...

This paper proposes an iterative learning control (ILC) for a micro stereo lithography (MSL) setup to enhance both the speed and quality of 3D printing. The MSL is built based on commercial confocal microscope while scanners x y axes are replaced with fast galvanometer considering requirements random trajectories in printing application. With stabilized scanners, frequency domain ILC applied precise operation desired 2D scanning trajectories. For scan up 400 features per second 0.6 × mm...

For highly precise motion of a galvanometer scanner that tracks periodic reference, learning control significantly decreases the tracking error. To achieve higher quality by reducing angular sensor noise, this paper investigates inversion-based iterative (IIC) can learn only at fundamental and harmonic frequencies reference. This enables to separate compensable error from noise be eliminated during in frequency domain. The analysis reveals tradeoff for reduction IIC design, proposes an...

This paper reports an iterative learning control (ILC) to compensate for the errors by switching operation and modeling inaccuracies a quasi-static (QS) MEMS mirror. The uncertainties in dynamics with between electrodes result undesirable oscillations beam positioning. A wideband frequency-domain ILC is proposed QS mirror flatness-based feedforward control. improvement of residual demonstrated reduced root mean square (RMS) 2 Hz 2-degree-amplitude sawtooth reference factor 69.9.

This paper presents the design and implementation of a scalable laser ranger finder (LRF)-based prototype system, which enables distance measurement precise localization multiple unmanned aerial vehicles (UAVs) in real-time. The system consists telescope camera as image acquisition components, supplemented by an LRF fast steering mirror (FSM) to obtain measurement. By combining optical path through dichroic mirror, is accurately aligned FSM based on angular position UAV within field view....

This paper presents a receding horizon control (RHC) for an input-delayed system. To begin with, by using the generalized Riccati method, finite optimal is derived quadratic cost function including two terminal weighting terms. The RHC easily obtained changing initial and final times of control. A linear matrix inequality (LMI) condition on matrices proposed to obtain monotonicity property, under which monotonically nonincreasing with time hence asymptotical stability guaranteed only if...

Accurate phase detection and control of nonlinear resonant MOEMS mirrors are crucial to achieve stable scanning motions high resolution imaging as needed in precision applications such lidar systems. This paper proposes a novel digital PLL that uses an asynchronous logic for driving the mirror immediate compensation, while clock speed is kept low. The detected by amplified current signal, generated movement comb-drive electrodes simple comparator circuit. An analysis proposed method shows...

This paper proposes capacitive charge-based self-sensing by integration of the comb drive intrinsic displacement current for resonant electrostatic MEMS mirrors in order to solve problem robust feedback laser scanning mobile light detection and ranging (Lidar) application. A two-channel switched integrator circuit is implemented determine deflection angle distinguish rotation direction from asymmetric charge. Parameters mirror are calibrated with an optical PSD setup. The parametrically...