scholarly journals A Task-Driven Feedback Imager with Uncertainty Driven Hybrid Control

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2610
Author(s):  
Burhan A. Mudassar ◽  
Priyabrata Saha ◽  
Marilyn Wolf ◽  
Saibal Mukhopadhyay
Keyword(s):  
Object Detection ◽  
Closed Loop ◽  
Hybrid Control ◽  
Hybrid Approach ◽  
Feedback System ◽  
Tracking Accuracy ◽  
Loop Control ◽  
Action Detection ◽  
Active Sensor ◽  
Loop Feedback

Deep Neural Network (DNN) systems tend to produce overconfident or uncalibrated outputs. This poses problems for active sensor systems that have a DNN module as the main feedback controller. In this paper, we study a closed-loop feedback smart camera from the lens of uncertainty estimation. The uncertainty of the task output is used to characterize and facilitate the feedback operation. The DNN uncertainty in the feedback system is estimated and characterized using both sampling and non-sampling based methods. In addition, we propose a closed-loop control that incorporates uncertainty information when providing feedback. We show two modes of control, one that prioritizes false positives and one that prioritizes false negatives, and a hybrid approach combining the two. We apply the uncertainty-driven control to the tasks of object detection, object tracking, and action detection. The hybrid system improves object detection and tracking accuracy on the CAMEL dataset by 1.1% each respectively. For the action detection task, the hybrid approach improves accuracy by 1.4%.

Driver Model Based on Controller with Open and Close Loop

2014 ◽  
Vol 889-890 ◽  
pp. 958-961
Author(s):  
Huan Ming Chen
Keyword(s):  
Closed Loop ◽  
Driver Model ◽  
Lateral Acceleration ◽  
Vehicle Model ◽  
Vehicle Handling ◽  
Loop Control ◽  
Driving Experience ◽  
Loop Feedback ◽  
Closed Loop Feedback ◽  
Target Path

It is very important to simulate driver's manipulation for people - car - road closed loop simulation system. In this paper, the driver model is divided into two parts, linear vehicle model is used to simulate the driver's driving experience, and closed-loop feedback is used to characterize the driver's emergency feedback. The lateral acceleration of vehicle is used as feedback in closed loop control. Simulation results show that the smaller lateral acceleration requires the less closed-loop feedback control. The driver model can accurately track the target path, which can be used to simulate the manipulation of the driver. The driver model can be used for people - car - road closed loop simulation to evaluate vehicle handling stability.

scholarly journals Three Closed-Loop Feedback Control System with Dual Disturbance Observers of an Optoelectronic Stable Control Platform

Electronics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 359 ◽  
Author(s):  
Hanwen Zhang ◽  
Yao Mao ◽  
Jiuqiang Deng ◽  
Huabo Liu
Keyword(s):  
Feedback Control ◽  
Disturbance Rejection ◽  
Closed Loop ◽  
Low Frequency ◽  
Tracking Accuracy ◽  
Visual Axis ◽  
Frequency Bands ◽  
Loop Feedback ◽  
Closed Loop Feedback ◽  
Stable Control

Disturbances presented in aeronautical imaging equipment can cause visual axis jitter, which directly leads to a reduction in closed-loop bandwidth and a decrease in tracking accuracy. The disturbance frequency affecting the stable control platform is mainly concentrated in the low- and middle-frequency bands, but the commonly used three closed-loop feedback control methods do not perform well in the disturbance rejection of those frequency bands. Moreover, the only disturbance observer in the acceleration loop cannot improve the low-band disturbance rejection capability due to the drift of the micro-electro-mechanical-system (MEMS) accelerometers in the low-frequency range. To solve these problems, this paper proposed dual disturbance observers (dual DOB) based on the disturbance information in the acceleration loop and the position loop. This design used two compensators to observe and compensate for the disturbances, which did not require additional sensors, and therefore did not increase system cost. Theoretical demonstrations and physical experiments showed that the designed method of the dual DOB not only improved the disturbance rejection capability of the low- and middle-frequency band of the optoelectronic stable control platform, but also improved the robustness of the system.

Capacitive-Based, Closed-Loop Frequency Control of Substrate-Integrated Cavity Tunable Filters

2014 ◽  
Vol 2014 (1) ◽  
pp. 000826-000831 ◽  
Author(s):  
Shahrokh Saeedi ◽  
William S. Wilson ◽  
Tyler R. Ashley ◽  
Hjalti H. Sigmarsson ◽  
Juseop Lee
Keyword(s):  
Feedback Control ◽  
Closed Loop ◽  
Frequency Tuning ◽  
Frequency Control ◽  
Center Frequency ◽  
Evanescent Mode ◽  
Loop Control ◽  
Custom Made ◽  
Metal Insulator Metal ◽  
Loop Feedback

In this paper, we present an integrated capacitive sensing technique that can be used to achieve closed-loop feedback control of variable capacitors. The technique is well suited for diaphragm-based actuators that can be used to tune the center frequency of microwave reconfigurable filters. A commercially available capaci-tance-to-digital converter is used to measure the capacitance of a custom-made monitoring capacitor. This capacitor is completely external to the filter structure and does not contribute to any added losses. A tunable, second-order, bandpass filter –using substrate-integrated, evanescent-mode cavity resonators– is created to demonstrate the concept. The frequency tuning is achieved using piezoelectric actuators to displace a flexible copper diaphragm that forms the top part of the loading capacitor. The monitoring capacitor consists of a second cavity that is mounted above the actuator forming a second air-filled, metal-insulator-metal capacitor. There exists a direct relationship between the monitoring capacitance and the loading capacitance in the evanescent-mode cavity. Therefore, by tracking the monitoring capacitance the center frequency of the filter can be monitored, which allows for direct in-situ closed-loop control of the filter. An algorithm for the tuning operation is presented, which includes an automatic calibration technique to initialize the controller. The effectiveness and repeatability of the technique is evaluated as the filter is tuned from 3.3 GHz to 3.7 GHz. Having stable feedback control integrated with this type of evanescent-mode cavity filters, brings the technology one step closer to actual fielding.

DYNAMIC FEEDBACK AND THE DESIGN OF CLOSED-LOOP DRUG DELIVERY SYSTEMS

1995 ◽  
Vol 03 (03) ◽  
pp. 711-718 ◽  
Author(s):  
JOHN MILTON ◽  
SUE ANN CAMPBELL ◽  
JACQUES BÉLAIR
Keyword(s):  
Drug Delivery ◽  
Negative Feedback ◽  
Closed Loop ◽  
Feedback System ◽  
Feedback Mechanism ◽  
Steady States ◽  
Dynamic Feedback ◽  
Negative Feedback Mechanism ◽  
Negative Feedback Loops ◽  
Loop Feedback

A closed-loop drug delivery system is constructed in which external negative feedback is used to regulate the dynamics of a time-delayed negative feedback mechanism which regulates hormone concentration. This results in a control system composed of two time-delayed negative feedback loops arranged in parallel. Stability regions in parameter space and the location of steady states are determined for the cases when the time delays are equal and when they are unequal. The advantage of this paradigm for drug delivery is that both the steady states and stability of the multiple loop feedback system can be influenced in a precisely controllable manner.

ADAPTIVE OPEN-PLUS-CLOSED-LOOP CONTROL METHOD OF MODIFIED FUNCTION PROJECTIVE SYNCHRONIZATION IN COMPLEX NETWORKS

2011 ◽  
Vol 22 (12) ◽  
pp. 1393-1407 ◽  
Author(s):  
HONGYUE DU
Keyword(s):  
Closed Loop ◽  
Control Method ◽  
Open Loop ◽  
Projective Synchronization ◽  
Closed Loop Control ◽  
Loop Control ◽  
Function Projective Synchronization ◽  
Advantages And Disadvantages ◽  
Modified Function Projective Synchronization ◽  
Loop Feedback

This paper investigates the modified function projective synchronization (MFPS) in drive-response dynamical networks (DRDNs) with different nodes, which means that systems in nodes are strictly different. An adaptive open-plus-closed-loop (AOPCL) control method is proposed, which is a practically realizable method and can overcome the model mismatched to achieve synchronization. It is well known that each of the close-loop and open-loop control method possesses some advantages and disadvantages. By combining their advantages, the open-plus-closed-loop (OPCL) control method was proposed by Jackson and Grosu. For arbitrary nonlinear dynamic systems, dx/dt = F(x,t), Jackson and Grosu proved that there exists solutions, x(t), in the neighborhood of any arbitrary goal dynamics g(t) that are entrained to g(t), through the use of an additive controlling action, K(g,x,t) = H(dg/dt,g) + C(g,t)(g(t) - x), which is the sum of the open-loop action, H(dg/dt,g), and a suitable linear closed-loop (feedback) action C(g,t). This method is a practically realizable method and robust to limited accuracy of data and effects of noise. The AOPCL control method preserve the merits of OPCL control method and its closed loop control part can be automatically adapted to suitable constants. Considering time-delays are always unavoidably in the practical situations, MFPS in DRDNs with time-varying coupling delayed is further investigated by the proposed method. Corresponding numerical simulations are performed to verify and illustrate the analytical results.

Study on Energy Saving PID Control of HST Tele-Control Vehicle

2013 ◽  
Vol 850-851 ◽  
pp. 636-639
Author(s):  
Jian Hua Chen ◽  
Xi Hui Mu ◽  
Feng Po Du ◽  
Kai Lv
Keyword(s):  
Diesel Engine ◽  
Pid Control ◽  
Closed Loop ◽  
Feedback System ◽  
Joint Control ◽  
Economic Region ◽  
Power Matching ◽  
Loop Feedback ◽  
Closed Loop Feedback ◽  
Speed Characteristic

Based on the analysis of power matching between diesel engine and HST, a simulation model was built by AMEsim. By using of simulation, the result of speed characteristic in closed loop feedback system was analyzed. The results show that power matching and joint control between diesel engine and HST is an effective way to improve the vehicles matching identity and ensure its working point in the economic region.

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