Steering Architecture Research Articles

Design of steering wheel torque with human-machine interaction for uncoupled shared steering

In the uncoupled shared steering architecture based on the steering-by-wire (SBW) system, direct access to road feel and automation-related information is unavailable to the driver. To address this problem, this paper proposes a steering wheel torque feedback model that considers human-machine interaction information. First, the model predictive control (MPC) is adopted in lateral vehicle control by automation. Then a fuzzy control-based control authority allocation model is applied to assign the control authority weight between the human driver and automation according to the value of the Path Lateral Hazard (PLH) Factor and the Driver’s Intent Evaluation (DIE) Factor. These two factors reflect the probability of lateral vehicle collision and the intensity of the driver’s driving intention, respectively. Next, the road feel feedback torque and the human-machine interface (HMI) feedback torque is incorporated in the steering wheel feedback torque model to enhance the driver’s experience in SBW vehicles and trust in the automation. The HMI feedback torque is designed to provide human drivers with information on control authority weight variation and desired angle deviation between the human driver and automation. Simulation and experiment results suggest that the proposed uncouple shared control method can accelerate driver acceptance of automation and provide the driver with a more intuitive steering experience.

Design of Computing-Aware Traffic Steering architecture for 5G Mobile User Plane

Design of Computing-Aware Traffic Steering architecture for 5G Mobile User Plane

Adaptive Suppression Method of LiDAR Background Noise Based on Threshold Detection

Background radiation in the LiDAR detection field of view is complex and variable, and the background noise generated can easily cause false alarms in the receiver, which affects the effective detection of the system. Through the analysis of the influence of background radiation noise of LiDAR on the detection performance, an adaptive suppression method of LiDAR background noise is proposed. This method realizes the rapid suppression of background noise in the instantaneous field of view through an adaptive threshold adjustment of current steering architecture with a back-end digital-to-analog converter (DAC) correction based on the principle of constant false alarm rate (CFAR) control. Aiming at the problem of accurate noise detection and quantification in a very short time, a dynamic comparator is used to replace the traditional continuous comparator. While detecting the number of noise pulses, the measurement of the pulse duration of noise is realized, which improves the accuracy of short-time noise detection. In order to verify the actual effect of the adaptive method, experiments were carried out based on the team’s self-developed LiDAR. The experimental results show that the measured noise ratio of the adaptive mode by using this method is the lowest. Even at 12 a.m., the noise ratio of the point cloud obtained by the adaptive mode is 0.012%, compared with 0.08% obtained by the traditional mode, which proves that this method has a good ability to suppress background noise. The proportion of noise reduction of the adaptive mode is more than 80% compared with the traditional mode. It achieves noise suppression through hardware at each detection, and each adjustment can be completed within a single period of pulse detection. Therefore, it has great advantages in real-time detection compared with the back-end software noise reduction processing method, and it is suitable for the application of LiDAR in the complex background environment.

Design of 8-Bit Hybrid Current Steering Digital to Analog Converter in a Standard 65nm CMOS Technology

A digital-to-analog converter (DAC) in electronics is a device that transforms digital signals into analog signals. There are various DAC architectures, and DAC's usefulness for a given application is determined by factors like resolution, INL, DNL, power consumption, maximum sampling frequency, and others. Because digital-to-analog conversion may damage a signal, a DAC with negligible faults for the application should be used. The current-steered digital-to-analog converter is well suited for high-speed applications because no buffers are needed for current steering architectures and the output is the total current drawn from the supply. In this paper, an 8-bit hybrid current steering digital-to-analog converter is proposed. Four cascode current sources with different weights are used in this architecture. The UMC 65nm CMOS technology was used to design the digital-to-analog converter. The INL and DNL were +0.19/-0.15 LSB and +0.28/-0.11 LSB respectively. The DAC uses roughly 3.25 mW at a supply voltage of 1.2V and a sample rate of 100 MHz. 12.751 mV was the output voltage at full scale. In comparison to earlier reports, the power, INL, DNL, and chip area used by the digital-to-analog converter in this architecture were significantly lower. It is appropriate for use in portable devices.

A Multi-Agent Simulation Evacuation Model Using The Social Force Model: A Large Room Simulation Study

Research on evacuation simulation has received significant attention over the past few decades. Disasters, whether they were caused by nature or by humans, which claimed lives were also the impetus for the establishment of various evacuation studies. Numerous research points to the possibility of simulating an evacuation utilizing the Social Force Model (SFM) and a leading person or leader, but without using the multi-agent architecture. Within the scope of this article, the multi-agent architecture for crowd steering that we suggest will be investigated. The architecture will utilize a model known as the Social Force Model to figure out how evacuees will move around the area. After this step, the model is simulated in NetLogo to determine whether the architecture can model the evacuation scenario. A simulation test is carried out for us to investigate the degree to which the behavior of the original SFM and the message-passing model is comparable to one another. The result demonstrates that the proposed architecture can simulate the evacuation of pedestrians. In addition, the simulation model can simulate utilizing the grouping strategy as well as the no grouping technique. The findings also showed that the model can capture many evacuation patterns, such as an arch-shaped pattern at the opening of the exit.

Non-Mechanical Beam Steering with Polarization Gratings: A Review

Polarization gratings (PGs) enable a novel architecture for dynamic non-mechanical steering of light over large angles and with large clear apertures. This beam steering approach has many applications in active sensing and optical communications. In this review, we describe some of the defining characteristics of this beam steering architecture and highlight several applications of the technology.

Collision Imminent Steering at High Speed Using Nonlinear Model Predictive Control

Collision imminent steering is an automotive active safety feature designed to perform an aggressive lane change to avoid a forward collision in the event that the system determines there is insufficient distance to avoid a collision by braking alone.In this paper, a collision imminent steering system is developed using nonlinear model predictive control to perform a lane change at high speed in a highway environment. Two formulations are presented: one formulation to show the theoretical minimum lane change distance within which a safe lane change can be performed, and a second formulation to find the minimum aggressive maneuver for a given lane change distance. The nonlinear model predictive control formulation is posed as a constrained optimization problem, where solutions obey hard safety constraints of the highway environment. Constraint aggregation techniques are analyzed and introduced to monitor the peak tire slip throughout the maneuver. Numerical simulations of a typical luxury sedan in a highway setting show that minimum distance required to change lanes is about half the limit braking distance. Hence, there is a window of feasibility where the vehicle cannot avoid collision by braking alone, but can change lanes safely and maintain a safe trajectory throughout the maneuver. Additional simulations show that an active four wheel steering architecture improves performance over front only steering.

A compact synthetic aperture digital holographic microscope with mechanical movement-free beam scanning and optimized active aberration compensation for isotropic resolution enhancement

This study proposes and demonstrates a compact synthetic aperture digital holographic microscope (SA-DHM) with mechanical movement-free beam scanning and optimized active aberration compensation. The SA-DHM system is equipped with a phase-only liquid crystal on silicon (LCoS) device as an active optical element to achieve a compact mechanical movement-free beam steering architecture with aberration correction. A rigorous optimization is conducted to modulate the LCoS device using the designed computer-generated holograms (CGH) to generate a high-quality point spread functions (PSF) for a wide range of scanning angles. An accurate aberration correction is studied with and without oil immersed conditions on microscope objective lens. The performance of the proposed method is analyzed with Siemens star target and the results show its potential capability to achieve isotropic resolution enhancement.

Implementation of digital-to-analog converter through CP-based GaAs/GaSb nanowire GAA-TFET

Digital-to-analog converter (DAC) is the most critical circuit of any chip which limits system performance and consume much power. Therefore, the focus of this work is the DAC implementation using GaAs/GaSb-based charge plasma nanowire GAA-TFET which provide better ON current at reduced ambipolarity and hence, reduce power consumption. Also, the linearity of the proposed device is much better than Si TFET due to the absence of random dopant fluctuation and hence, improves DAC accuracy. The DAC implemented here is the R–2R and current steering architecture which is the first ever known work of a charge plasma-based hetero-material nanowire TFET. For the DAC implementation, Verilog A lookup table is created from the simulated results of this device from TCAD Silvaco and rest of the circuit simulation is carried out in Cadence. Finally, DAC performance metrics have been analyzed and found that efficiency of current steering has been drastically improved compared to R–2R architecture.

A 2 GS/s, 6-bit DAC for UWB Applications In 0.18 ㎛ CMOS Technology

To satisfy higher and higher transmission rate and broadband requirement of modern communication, high-speed, low-resolution Digital-to-Analog Converters (DACs) becomes the key element. In this paper, the design of a 2 GS/s, 6 bit DAC without calibration for Ultra-wideband (UWB) applications, is presented. The DAC is based on current steering architecture and is segmented with 4 bit unary and 2 bit binary. To realize larger linear range and fast switching, the source degeneration switch is designed instead of the traditional differential switch. The DAC is designed and taped-out in SMIC 0.18 μm CMOS technology and the area is 975 μm☓775 μm. The wafer bonding measurement results shows that the DNL is 0.11 LSB, INL is 0.25 LSB. Under a clock frequency of 2 GHz, the DAC can achieve a SFDR of 51 dB for input signal of 6MHz, and a SFDR of 32.4 dB for Nyquist input while the power consumption is 79 mW.

Peripherally Excited Phased Array Architecture for Beam Steering with Reduced Number of Active Elements

An electronically scannable phased array antenna architecture is proposed with a drastically reduced number of active antenna elements. The proposed approach is based on the concept of Huygens’ metasurfaces, where the fields in a given region are controlled by active or passive electromagnetic sources on the boundary surface of this region. Using this approach, arbitrary plane waves are excited inside a metallic cavity by peripheral sources, and the cavity is engineered to radiate a single or multiple pencil beams through appropriately perforated slots on its top surface. The proposed peripherally excited (PEX) phased array architecture generates pencil beams that are electronically scanned by controlling the amplitudes and phases of the peripheral sources. The proposed concept has the potential to drastically reduce the required number of active elements in 2-D phased arrays without compromising directivity. However, the possible beam-pointing directions are constrained.

32-GS/s 6-bit DAC based on SiGe technology for IM-DD OFDM systems with non-uniform quantization.

In this paper, we design and fabricate a 32-GS/s 6-bit digital-to-analog convertor (DAC) based on SiGe technology. The DAC uses double sampling technique and segment current steering architecture to achieve high dynamic linearity. A corrector circuit is proposed to suppress the duty cycle error for linearity optimization. The spurious free dynamic range (SFDR) is above 31.5 dBc over the Nyquist bandwidth at the sampling rate of 32-GS/s. A full-rate input interface is integrated to realize data exchange with field-programmable gate array (FPGA). The experimental results show that the net data rate of 50-Gb/s orthogonal frequency division multiplexing (OFDM) signals with non-uniform quantization can be generated by the designed and fabricated DAC. The OFDM signal transmission over 10-km standard single mode fiber (SSMF) with 64-quadrature amplitude modulation (QAM) and 128-QAM formats have been successfully achieved.

A 4-Bit 5 GS/s Current Steering DAC Integrated Circuit

In order to satisfy the higher and higher transmission rate and broadband requirement of modern communication, a 4-bit 5 GS/s digital-to-analog converter (DAC) integrated circuit is presented. The DAC circuit is based on current steering architecture and segmented with a 4 bit unary. The circuit is designed and analyzed in TSMC 0.18 μm CMOS technology. The chip size is 0.675 mm 0.525 mm. Simulation results show that the maximum integral nonlinearity (INL) is 0.15 LSB. The DAC can achieve a spurious-free dynamic range (SFDR) of 22.76 dB under a clock frequency of 5 GHz with an input signal frequency of 250 MHz, while the power consumption is 11.6 mW.

Vision Based Autonomous Lateral and Longitudinal Control System

Automation combined with the increasing market penetration of on-line communication, navigation, and advanced driver assistance systems will ultimately result in Intelligent Vehicle Highway Systems. Advanced Vehicle Control Systems (AVCS) is a key technology for Intelligent Transportation System (ITS) and Intelligent Vehicle Control System (IVCS). The unmanned control of the steering wheel is one of the most important challenges faced by the researchers. This paper proposes 1D sensor calibration algorithm which makes the vehicle to identify the track independent of various lighting conditions. Pre-processing algorithm helps in finding the position and orientation of the vehicle in the track. A novel control architecture for automatic steering, acceleration and braking control of a self guided vehicle has been proposed which consists of cascaded Kalman filter with PID steer control algorithm. It provides smooth tracking over the entire track. Adaptive speed control based on speed difference and acceleration control algorithm based on steer error are used. These algorithms make the vehicle to optimally manoeuvre the track. The experimental results show that the combination of Kalman filter with PID for lateral control reduces trajectory error to a minimum level and adaptive speed control algorithm for longitudinal control provides smooth speed over the entire track.

Implementation of AVCS using Kalman Filter and PID Controller in Autonomous Self Guided Vehicle

Advanced Vehicle Control Systems (AVCS) is a key technology for Intelligent Transportation System (ITS) and Intelligent Vehicle Control System (IVCS). AVCS involves automatic steering, acceleration and braking control of fully autonomous vehicles. The unmanned control of the steering wheel is one of the most important challenges faced by the researchers. This paper proposes control architecture for automatic steering, acceleration and braking control of a self guided vehicle. Self guided vehicle is a line follower which tracks a black line on a white surface, through an array of infrared sensors. In line following, the readings that show deviation from the line are considered as lateral error and the proposed algorithm works towards minimizing the lateral error. Calculation of the lateral error and filtering the error values using Kalman filter is the first level of error calculation. Kalman filter protects the steering action from erroneous sensor values. PID control algorithm uses the filtered value and calculates the required steer to achieve the zero lateral error. The proposed adaptive speed control algorithm uses the speed boosting techniques for the longitudinal control of the vehicle. The experimental results show that the combination of Kalman filter with PID for lateral control reduces trajectory error to a minimum level and adaptive speed control algorithm for longitudinal control provides smooth accelerations over the entire track. Thus proposed algorithm gives better performance in both the lateral and longitudinal control.

A 10-bit Low-Power Small-Area High-Swing CMOS DAC

The design and measurements of a prototype general purpose digital to analog converter for readout systems in high energy physics experiments are presented. The main goals for the proposed DAC are low power consumption, small die area and high-swing voltage output. The 10-bit DAC design is based on a current steering architecture which includes a high-swing class AB output amplifier. The prototype ASIC is fabricated using 2P-4M 0.35- ?m technology. Measurements of maximum differential (DNL) and integral (INL) nonlinearity both show 0.42 LSB. The total power consumption is below 0.6 mW while the core area is 0.18 mm2.

A 12-Bit Nonlinear DAC for Direct Digital Frequency Synthesis

A 12-bit nonlinear digital-to-analog converter (DAC) was fabricated in a 0.35-mum SOI CMOS process. The nonlinear DAC can implement a piecewise-linear approximation to a sine function and results in significant reduction of complexity and power dissipation when used in direct digital frequency synthesizers (DDFSs). The DDFS look-up table only needs to store offset and gain values for each segment. The look-up table size can be reduced from 11K bits to 544 bits for a 12-bit DDFS with 72 dB spurious-free dynamic range (SFDR). The nonlinear DAC consists of a 12-bit binary-weighted offset DAC and a multiplying DAC. The DACs use a current steering architecture for high-speed operation and the 5 most significant bits of the offset DAC are unary encoded to reduce glitches. The multiplying DAC consists of binary-weighted current sources switched by the partial products of the inputs. Test results show that the DAC has 12-bit accuracy after digital trimming, operates up to 600 MS/s and provides differential outputs of 0.5 V into 50 Omega loads. The SFDR is over 60 dBc below 20 MHz with a maximum of 72 dBc. Radiation tests show the nonlinear DAC can tolerate a total ionizing dose of 200 Krad Si.

Computational steering on distributed systems: Indoor comfort simulations as a case study of interactive CFD on supercomputers

This paper presents the current state of a computational steering system for interactive computational fluid dynamics (CFD) simulations, allowing engineers to simulate interactively indoor climate and to evaluate human comfort. The tools presented support cooperative planning and design by providing means for interactively adding, removing and modifying geometry and boundary conditions online during a CFD simulation. To ensure interactivity and short-latency updates even for high-resolution runs the parallel Lattice–Boltzmann-based simulation kernel is optimized for high-performance computing systems. Emphasis is placed on the computational steering architecture, connecting a supercomputer with one or more visualization workstations. In particular, we show how a high-performance communication between simulation and visualization or steering front-end can be achieved together with preserving a flexible mechanism of on-the-fly attachment of multiple cooperation clients.

Steering via the image in local, distributed and collaborative settings

AbstractComputational steering is a valuable mechanism for scientific investigation in which the parameters of a running program can be altered and the results visualized immediately. In a previous paper we put forward an architecture for computational steering that recognizes visualization as both the logical output and the input route. In this paper we investigate the practicalities of applying this architecture in local, distributed and collaborative steering. The work adopts a state‐transition modelling approach, keeping parameters and results together in the display in order to present information consistently. The outcome is a manageably small set of states that could apply to many different simulations. We also present the results of a preliminary user study on the demonstrator we have constructed. Copyright © 2007 John Wiley & Sons, Ltd.

Steering of Discrete Event Systems: Control Theory Approach

Runtime verification involves monitoring the system at runtime to check for conformance of the execution trace to user defined safety properties. Typically, run-time verifiers do not assume a system model and hence cannot predict violations until they occur. This limits the practical applicability of runtime verification. Steering is the process of predicting the occurrence of violations and preventing them by controlling system execution. Steerers can achieve this using a limited knowledge of the system model even in situations where it is infeasible to store the entire model. In this paper, we explore a control-theoretic view of steering for discrete event systems. We introduce an architecture for steering and also describe different steering paradigms.