scholarly journals Segment Drift Control with a Supervision Mechanism for Autonomous Vehicles

Actuators ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 219
Author(s):  
Ming Liu ◽  
Bo Leng ◽  
Lu Xiong ◽  
Yize Yu ◽  
Xing Yang
Keyword(s):  
Autonomous Vehicles ◽  
Open Loop ◽  
Actual State ◽  
Extreme Conditions ◽  
Strong Nonlinearity ◽  
Test Results ◽  
Loop Control ◽  
Whole Process ◽  
Vehicle Test ◽  
Drift Control

Stable maneuverability is extremely important for the overall safety and robustness of autonomous vehicles under extreme conditions, and automated drift is able to ensure the widest possible range of maneuverability. However, due to the strong nonlinearity and fast vehicle dynamics occurring during the drift process, drift control is challenging. In view of the drift parking scenario, this paper proposes a segmented drift parking method to improve the handling ability of vehicles under extreme conditions. The whole process is divided into two parts: the location approach part and the drift part. The model predictive control (MPC) method was used in the approach to achieve consistency between the actual state and the expected state. For drift, the open-loop control law was designed on the basis of drift trajectories obtained by professional drivers. The drift monitoring strategy aims to monitor the whole drift process and improve the success rate of the drift. A simulation and an actual vehicle test platform were built, and the test results show that the proposed algorithm can be used to achieve accurate vehicle drift to the parking position.

Closed-Loop Turbulence Control: Progress and Challenges

2015 ◽  
Vol 67 (5) ◽  
Author(s):  
Steven L. Brunton ◽  
Bernd R. Noack
Keyword(s):  
Closed Loop ◽  
Response Times ◽  
Aerodynamic Drag ◽  
Model Identification ◽  
Open Loop ◽  
Mixing Enhancement ◽  
Strong Nonlinearity ◽  
Open Problems ◽  
Loop Control ◽  
Turbulence Control

Closed-loop turbulence control is a critical enabler of aerodynamic drag reduction, lift increase, mixing enhancement, and noise reduction. Current and future applications have epic proportion: cars, trucks, trains, airplanes, wind turbines, medical devices, combustion, chemical reactors, just to name a few. Methods to adaptively adjust open-loop parameters are continually improving toward shorter response times. However, control design for in-time response is challenged by strong nonlinearity, high-dimensionality, and time-delays. Recent advances in the field of model identification and system reduction, coupled with advances in control theory (robust, adaptive, and nonlinear) are driving significant progress in adaptive and in-time closed-loop control of fluid turbulence. In this review, we provide an overview of critical theoretical developments, highlighted by compelling experimental success stories. We also point to challenging open problems and propose potentially disruptive technologies of machine learning and compressive sensing.

scholarly journals Dynamic Analysis and Control of the Clutch Filling Process in Clutch-to-Clutch Transmissions

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Wei Guo ◽  
Yanfang Liu ◽  
Jing Zhang ◽  
Xiangyang Xu
Keyword(s):  
Control Method ◽  
Adaptive Method ◽  
Open Loop ◽  
Control Parameters ◽  
Loop Control ◽  
Shift Quality ◽  
Control Precision ◽  
Torque Capacity ◽  
Vehicle Test ◽  
Fuzzy Adaptive

Clutch fill control in clutch-to-clutch transmissions influences shift quality considerably. An oncoming clutch should be applied synchronously with the release of an offgoing clutch to shift gear smoothly; therefore, the gap between the piston and clutch plates should be eliminated when the torque capacity is near zero at the end of the clutch fill phase. Open-loop control is typically implemented for the clutch fill because of the cost of pressure sensor. Low control precision causes underfill or overfill to occur, deteriorating shift quality. In this paper, a mathematical model of an electrohydraulic clutch shift control system is presented. Special dynamic characteristic parameters for optimal clutch fill control are subsequently proposed. An automatic method for predicting initial fill control parameters is proposed to eliminate distinct discrepancies among transmissions caused by manufacturing or assembling errors. To prevent underfill and overfill, a fuzzy adaptive control method is proposed, in which clutch fill control parameters are adjusted self-adaptively and continually. Road vehicle test results proved that applying the fuzzy adaptive method ensures the consistency of shift quality even after the transmission’s status is changed.

Rancang Bangun Quadcopter untuk Terbang Mengikuti Dinding Menggunakan Sensor Jarak Ultrasonik HC-SR04

2020 ◽  
Vol 6 (2) ◽  
pp. 75-84
Author(s):  
Indra Maulidin ◽  
Muliady Muliady ◽  
Yohana Susanthi
Keyword(s):  
Movement Control ◽  
Open Loop ◽  
Maximum Height ◽  
Test Results ◽  
Open Loop Control ◽  
Limit Values ◽  
Loop Control ◽  
Upper Limit ◽  
Distance Sensor

Makalah ini memaparkan perancangan dan realisasi sebuah quadcopter menggunakan sensor jarak ultrasonic HC-SR04 agar dapat terbang mengikuti dinding. Algoritma yang digunakan pada realisasi quadcopter adalah algoritma Wall Follower. Fokus pembahasan sistem tersebut adalah mengimplementasikan algoritma Wall Follower pada quadcopter agar dapat terbang navigasi dalam ruang dengan cara mengikuti dinding. Kontrol pergerakan roll menggunakan mode pengontrol ON-OFF Hysteresis sedangkan pada pergerakan yaw digunakan mode pengontrol open-loop. Nilai batas bawah dan batas atas yang digunakan pada kontrol ON-OFF Hysteresis adalah 70 cm dan 100 cm. Hasil pengujian menunjukkan quadcopter berhasil terbang mengikuti dinding sejauh 10,2 m dengan ketinggian maksimum 2,14 m. This paper explained the design and realization of a quadcopter using the HC-SR04 ultrasonic distance sensor so that it can fly following the wall. The algorithm used in the quadcopter design is the Wall Follower algorithm. The focus of the discussion of the system is implementing a Wall Follower algorithm to the quadcopter so that it can navigate following the wall. The roll movement control was using Hysteresis ON-OFF control and the yaw movement control was using open-loop control. The lower and upper limit values that were used in the Hysteresis ON-OFF control are 70 cm and 100 cm. The test results show the quadcopter can fly following the wall as far as 10.2 m and reaches a maximum height of 2,14 m.

Open-loop control of compensation for optical propagation through a turbulent shear flow

1998 ◽  
Author(s):  
C. Truman ◽  
Lenore McMackin ◽  
Robert Pierson ◽  
Kenneth Bishop ◽  
Ellen Chen
Keyword(s):  
Shear Flow ◽  
Open Loop ◽  
Turbulent Shear ◽  
Turbulent Shear Flow ◽  
Open Loop Control ◽  
Loop Control ◽  
Optical Propagation

scholarly journals Sensuator: A Hybrid Sensor–Actuator Approach to Soft Robotic Proprioception Using Recurrent Neural Networks

Actuators ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 30
Author(s):  
Pornthep Preechayasomboon ◽  
Eric Rombokas
Keyword(s):  
Neural Networks ◽  
Recurrent Neural Networks ◽  
Linear Models ◽  
Open Loop ◽  
Proof Of Concept ◽  
State Estimator ◽  
Loop Control ◽  
Practical Applications ◽  
Soft Actuator ◽  
The Cost

Soft robotic actuators are now being used in practical applications; however, they are often limited to open-loop control that relies on the inherent compliance of the actuator. Achieving human-like manipulation and grasping with soft robotic actuators requires at least some form of sensing, which often comes at the cost of complex fabrication and purposefully built sensor structures. In this paper, we utilize the actuating fluid itself as a sensing medium to achieve high-fidelity proprioception in a soft actuator. As our sensors are somewhat unstructured, their readings are difficult to interpret using linear models. We therefore present a proof of concept of a method for deriving the pose of the soft actuator using recurrent neural networks. We present the experimental setup and our learned state estimator to show that our method is viable for achieving proprioception and is also robust to common sensor failures.

Design of Static Test Model for Three-Tower Cable-Stayed Self-Anchored Suspension Composed Bridge

2011 ◽  
Vol 243-249 ◽  
pp. 1528-1535
Author(s):  
Yu Zhao ◽  
Yong Jun Zhou ◽  
Jing Sun ◽  
Jin Tao Tang ◽  
Xu Li
Keyword(s):  
Complex System ◽  
Finite Element ◽  
Element Model ◽  
Test Model ◽  
Test Results ◽  
Static Test ◽  
Whole Process ◽  
Aesthetic Appearance ◽  
Load Carrying ◽  
Novel Structures

Cable-stayed self-anchored suspension composed bridges have novel structures and aesthetic appearance with complex system and difficulty for design and construction. In order to acquire a better knowledge of the load-carrying capability of this type of bridges, based on a real bridge and the theory of abnormal similarity, a full-bridge scaled down(1:20) test model was built to simulate the whole process of construction. The test results were preferably fit the theoretical calculation value. It can be seen that the design of the bridge was reasonable, and the accuracy of the calculation of finite element model was verified at the same time. The test and the related results can be used as the reference for the test and design of the similar bridges.

Precise open-loop control of MEMS deformable mirror shape

2008 ◽  
Author(s):  
Thomas Bifano ◽  
Jason Stewart ◽  
Alioune Diouf
Keyword(s):  
Open Loop ◽  
Deformable Mirror ◽  
Open Loop Control ◽  
Loop Control
Sign in / Sign up

Export Citation Format

Share Document