Reducing RMS on Wheel Load in ABS-Braking Situations by Control of Semi-Active Suspension

2006 ◽  
Author(s):  
Tobias Niemz ◽  
Hermann Winner
Keyword(s):  
Control Algorithm ◽  
Control Strategies ◽  
Simulation Models ◽  
Time Behavior ◽  
Test Rig ◽  
Passenger Cars ◽  
Wheel Load ◽  
Minimax Control ◽  
Change Effect ◽  
Braking Distance

In the presented research project the authors’ goal is to determine the potential of reduction of braking distance by automatic control of active dampers in passenger cars. Control strategies are being developed and tested in simulation models to be validated afterwards in test stand trials and test drives. In the presented paper the model assumptions regarding the vibration behavior of the vertical dynamics of the testing vehicle were checked. The assumptions regarding the influence on the wheel load of adaptive dampers could be verified and information about the time behavior and about the strength of the damper change effect could be gained. A control algorithm for the active dampers was developed and implemented in a testing vehicle. The control algorithm, which is called MiniMax control, makes it possible to reduce the RMS on dynamic wheel load in non-braking situations significantly. This could be shown in test rig trials as well as in test drives with defined obstacles. In full braking test drives the chosen controller is able to reduce the RMS on wheel load at initial velocities up to 70 km/h.

scholarly journals Experimental Analysis of a Novel Double Damper System with Semi-Active Control

Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1518
Author(s):  
Anish Gorantiwar ◽  
Rajvardhan Nalawade ◽  
Arash Nouri ◽  
Saied Taheri
Keyword(s):  
Control Algorithm ◽  
Performance Metrics ◽  
Control Strategies ◽  
Normal Load ◽  
Data Acquisition System ◽  
Test Rig ◽  
Strong Basis ◽  
Acceleration Data ◽  
Separate Control ◽  
Active Damper

An experimental study was conducted to compare the performance of an in-house built novel double semi-active damper against a conventional semi-active single damper. Different performance metrics were analyzed, and the performance of the two dampers was evaluated based on these metrics. A Hybrid Skyhook–Groundhook control algorithm was developed and implemented on the variable orifice double damper. The semi-active single damper is governed via two separate control strategies, namely—Skyhook and Groundhook control, respectively. The effectiveness of each algorithm is better understood by adding a normal load on top of the Shock Dyno, thus modifying it to act as a quarter car test rig. The sprung and unsprung acceleration data are collected via the accelerometers mounted on the Shock Dyno through a Data Acquisition System. The results obtained from this experiment provide a strong basis that the semi-active double damper performs better in terms of the comfort cost than that of the commercial semi-active single dampers.

scholarly journals Performance of an Electromagnetic Bearing for the Vibration Control of a Supercritical Shaft

1987 ◽  
Vol 201 (3) ◽  
pp. 201-212 ◽  
Author(s):  
C D Bradfield ◽  
J B Roberts ◽  
R Karunendiran
Keyword(s):  
Vibration Control ◽  
Control Algorithm ◽  
Control Strategies ◽  
Single Point ◽  
Test Rig ◽  
Rotating Shaft ◽  
Linear Spring ◽  
Measured Displacement ◽  
Control Forces ◽  
Electromagnetic Bearing

The flexural vibrations of a rotating shaft, running through one or more critical speeds, can be reduced to an acceptably low level by applying suitable control forces at an intermediate span position. If electromagnets are used to produce the control forces then it is possible to implement a wide variety of control strategies. A test rig is described which includes a microprocessor-based controller, in which such strategies can be realized in terms of software-based algorithms. The electromagnet configuration and the method of stabilizing the electromagnet force–gap characteristic are discussed. The bounds on the performance of the system are defined. A simple control algorithm is outlined, where the control forces are proportional to the measured displacement and velocity at a single point on the shaft span; in this case the electromagnet behaves in a similar manner to that of a parallel combination of a linear spring and damper. Experimental and predicted performances of the system are compared, for this type of control, where various programmable rates of damping are applied.

Development of Dedicated Controller for HVAC

2012 ◽  
Vol 430-432 ◽  
pp. 1472-1476
Author(s):  
Jin Ming Yang ◽  
Yi Lin
Keyword(s):  
Fuzzy Control ◽  
Control Algorithm ◽  
Control Strategies ◽  
Control Software ◽  
Interface Circuits ◽  
Pid Algorithm ◽  
Hardware Interface ◽  
Hvac Control ◽  
Fuzzy Control Algorithm

This article describes the development of a dedicated controller for HVAC control, and introduces the hardware interface circuits about some main chip on controller. In addition, the article also explains composition and principle about control software applied to the controller, further more points out that the fuzzy control algorithm is more reasonable than the PID algorithm for most HVAC control and dedicated control strategies play an important role for HVAC control.

The Use of Damping Based Semi-Active Control Algorithms in the Mechanical Smart-Spring System

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Wander Gustavo Rocha Vieira ◽  
Fred Nitzsche ◽  
Carlos De Marqui
Keyword(s):  
Active Control ◽  
Control Algorithm ◽  
Control Strategies ◽  
Vibration Reduction ◽  
Flow Analysis ◽  
Coupled Systems ◽  
Control Technique ◽  
Control Algorithms ◽  
Control Techniques ◽  
Spring Mechanism

In recent decades, semi-active control strategies have been investigated for vibration reduction. In general, these techniques provide enhanced control performance when compared to traditional passive techniques and lower energy consumption if compared to active control techniques. In semi-active concepts, vibration attenuation is achieved by modulating inertial, stiffness, or damping properties of a dynamic system. The smart spring is a mechanical device originally employed for the effective modulation of its stiffness through the use of semi-active control strategies. This device has been successfully tested to damp aeroelastic oscillations of fixed and rotary wings. In this paper, the modeling of the smart spring mechanism is presented and two semi-active control algorithms are employed to promote vibration reduction through enhanced damping effects. The first control technique is the smart-spring resetting (SSR), which resembles resetting control techniques developed for vibration reduction of civil structures as well as the piezoelectric synchronized switch damping on short (SSDS) technique. The second control algorithm is referred to as the smart-spring inversion (SSI), which presents some similarities with the synchronized switch damping (SSD) on inductor technique previously presented in the literature of electromechanically coupled systems. The effects of the SSR and SSI control algorithms on the free and forced responses of the smart-spring are investigated in time and frequency domains. An energy flow analysis is also presented in order to explain the enhanced damping behavior when the SSI control algorithm is employed.

Comparison of Peanut Dryer Control Strategies1

1996 ◽  
Vol 23 (2) ◽  
pp. 86-90 ◽  
Author(s):  
C. L. Butts
Keyword(s):  
Control Algorithm ◽  
Energy Savings ◽  
Control Strategies ◽  
Size Distributions ◽  
Curing Time ◽  
Kernel Size ◽  
Milling Quality ◽  
Set Point ◽  
Net Revenue ◽  
Hourly Basis

Abstract Peanuts were mechanically cured from field moisture contents ranging from 11.5 to 32.8% wet basis to levels acceptable for marketing (< 10.5%) using two dryer control strategies. The first control algorithm consisted of a constant thermostat setting of 39 C, while the second required manual thermostat control on an hourly basis such that the minimum plenum relative humidity was between 40 and 60% and the maximum plenum temperature was less than 39 C. The average drying rate using the variable thermostat set point (0.3%/hr) was half that obtained with the constant set point (0.6%/hr). Average curing time for the variable thermostat setting was 56% longer than for the peanuts cured using the constant thermostat. Fuel consumption was reduced by approximately 30% using the variable set point. Kernel size distributions and milling quality indicated by bald kernels were significantly better (P ≤ 0.1) for peanuts cured using the variable thermostat control. Increasing available dryer capacity by 40% would allow the buying point manager to handle the same amount of peanuts during the same harvest interval. Economic analysis showed that the annual capital cost for additional drying equipment could not be offset by energy savings alone. Based on increased shelled product value and energy savings, shellers could realize an increase in net revenue of approximately $14/1000 kg of farmers stock peanuts by using a variable thermostat set point.

scholarly journals Modified Space Vector Modulated Z Source Inverter with Effective DC Boost and Lowest Switching Stress

2010 ◽  
Vol 7 (1) ◽  
pp. 70 ◽  
Author(s):  
S. Thangaprakash ◽  
A. Krishnan
Keyword(s):  
Control Algorithm ◽  
Degrees Of Freedom ◽  
Control Strategies ◽  
Input Voltage ◽  
Duty Ratio ◽  
Space Vector ◽  
Voltage Vector ◽  
Voltage Stress ◽  
Capacitor Voltage ◽  
Full Utilization

 This paper presents a modified control algorithm for Space Vector Modulated (SVM) Z-Source inverters. In traditional control strategies, the Z-Source capacitor voltage is controlled by the shoot through duty ratio and the output voltage is controlled by the modulation index respectively. Proposed algorithm provides a modified voltage vector with single stage controller having one degree of freedom wherein traditional controllers have two degrees of freedom. Through this method of control, the full utilization of the dc link input voltage and keeping the lowest voltage stress across the switches with variable input voltage could be achieved. Further it offers ability of buck-boost operation, low distorted output waveforms, sustainability during voltage sags and reduced line harmonics. The SVM control algorithm presented in this paper is implemented through Matlab/Simulink tool and experimentally verified with Z-source inverter prototype in the laboratory. 

scholarly journals RESEARCH AND IMPROVEMENT OF PRECISE ANGLE CONTROL SYSTEM

2010 ◽  
Vol 2 (1) ◽  
pp. 95-98
Author(s):  
Sigitas Šakalinis
Keyword(s):  
Control System ◽  
Control Algorithm ◽  
Controller Design ◽  
Stepper Motor ◽  
Main Task ◽  
Test Rig ◽  
Positioning Accuracy ◽  
Technical University

The main task was investigation and precision improve­ment for a positioning drive, installed in a test rig for testing and calibration of the geodetic instruments at Vilnius Gediminas Technical University, Institute of Geodesy. Replacement of a stepper motor and a microstepping controller design increased positioning accuracy to 0.1''. Vibrations and noise of the test rig were significantly decreased using an optimized control algorithm, where resonating step frequencies were bypassed. The time of scale rotation between measurements (every 30°) achieved less than 1.5 min. Methods of the further precision improvement were selected, and this research is in progress now.

Experimental Study on H∞ Control for United Brake of Electric Vehicle

2011 ◽  
Vol 204-210 ◽  
pp. 498-501
Author(s):  
Chuan Wei Zhang
Keyword(s):  
Robust Control ◽  
Electric Vehicle ◽  
Pid Control ◽  
Control Strategies ◽  
Tracking Error ◽  
Research Work ◽  
Response Speed ◽  
Rotational Inertia ◽  
Variable Load ◽  
Braking Distance

This paper discusses different united brake control strategies of electric vehicle (EV), presents a novel H∞ robust united brake control strategy for EV. Research work is done under different conditions namely variable battery voltage and variable load rotational inertia, separately. A comparison between conventional PID control and H∞ robust control is done when they are applied to the above mentioned conditions. Under the united brake condition, the experimental results show that the braking distance is shortened by the united brake system in the emergent brake; the braking ability of the EV is improved. H∞ robust control has better performance than the traditional PID control both in steady-state tracking error and response speed.

Assessment and design of real world driving cycles targeted to the calibration of vehicles with electrified powertrain

2021 ◽  
pp. 146808742110387
Author(s):  
Stylianos Doulgeris ◽  
Zisimos Toumasatos ◽  
Maria Vittoria Prati ◽  
Carlo Beatrice ◽  
Zissis Samaras
Keyword(s):  
Real World ◽  
Simulation Models ◽  
Cost Effective ◽  
Operational Parameters ◽  
Virtual Design ◽  
Passenger Cars ◽  
Real World Data ◽  
Vehicle Simulation ◽  
Driving Cycles ◽  
The Impact

Vehicles’ powertrain electrification is one of the key measures adopted by manufacturers in order to develop low emissions vehicles and reduce the CO2 emissions from passenger cars. High complexity of electrified powertrains increases the demand of cost-effective tools that can be used during the design of such powertrain architectures. Objective of the study is the proposal of a series of real-world velocity profiles that can be used during virtual design. To that aim, using three state of the art plug-in hybrid vehicles, a combined experimental, and simulation approach is followed to derive generic real-world cycles that can be used for the evaluation of the overall energy efficiency of electrified powertrains. The vehicles were tested under standard real driving emissions routes, real-world routes with reversed order (compared to a standard real driving emissions route) of urban, rural, motorway, and routes with high slope variation. To enhance the experimental activities, additional virtual mission profiles simulated using vehicle simulation models. Outcome of the study consists of specific driving cycles, designed based on standard real-world route, and a methodology for real-world data analysis and evaluation, along with the results from the assessment of the impact of different operational parameters on the total electrified powertrain.

A Mixed Sideslip Yaw Rate Stability Controller for Over-Actuated Vehicles

2021 ◽  
Author(s):  
Alex Gimondi ◽  
Matteo Corno ◽  
Sergio M. Savaresi
Keyword(s):  
Control Strategies ◽  
Reference Signal ◽  
Stability Control ◽  
Critical Conditions ◽  
Passenger Cars ◽  
Single Input Single Output ◽  
Yaw Rate ◽  
Single Output ◽  
Precise Knowledge ◽  
Mixed Approach

Abstract Electronic stability control (ESC) has become a fundamental safety feature for passenger cars. Commonly employed ESCs are based on differential braking. Nevertheless, electric vehicles’ growth, particularly those featuring an over-actuated configuration with individual wheel motors, allows for maintaining driveability without slowing down the vehicle. Standard control strategies are based on yaw rate tracking. The reference signal is model-based and needs precise knowledge of the friction coefficient. To increase the system robustness, more sophisticated approaches that include vehicle sideslip are introduced. Still, it is unclear how the two signals have to be weighted, and rarely proposed controllers have been experimentally validated. In this paper, we present a mixed sideslip and yaw rate stability controller. The mixed approach allows to address the control design as a single-input single-output problem simplifying the tuning process. Furthermore, we explain the rationale behind the choice of the weighting parameter. Eventually, the proposed ESC is validated following EU regulation in simulation and with an experimental vehicle on dry asphalt and snow. The results obtained in all the performed tests demonstrate that the proposed control strategy is robust and effective. The mixed approach is able to halve the sideslip in critical conditions with respect to a pure yaw rate approach.

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