Event-Driven CNC Modularized Sewing Platform

2013 ◽  
Author(s):  
Xiaohui Xie ◽  
Cui Ma ◽  
Bingzhe Han ◽  
Ruxu Du
Keyword(s):  
Cooperative Control ◽  
Position Control ◽  
Control Method ◽  
Thread Cutting ◽  
Sewing Machine ◽  
Precise Control ◽  
Event Driven ◽  
Communication Ability ◽  
Uncertain Time ◽  
Lockstitch Sewing

With ever increased demand for quality and productivity, modern industrial sewing machine is becoming very complex and requiring sophisticated control. This paper presents a control platform that can be used for all kinds of lockstitch sewing machines. This event-driven control platform can support various kinds of sewing operations, from simple lockstitches, to X-Y lockstitches, as well as thread cutting. The key to the control platform is the precision cooperative control. First, for each motion axis, both the position and the velocity must be precisely controlled. In addition, the multi-axis motions must be synchronized to achieve high accuracy stitches. In order to increase the machine flexibility and decrease variety, a generalized and modularized sewing platform is proposed in this paper. It can be assembled with common lockstitch sewing machine and achieve several kinds of sewing functions. This platform module has independent driving capability to fulfill special movement and the communication ability to collaborate with other modules. Besides the modularized mechanism, the reusable and reconfigurable control system is the key point. For industry sewing machine, the important functions are the single-axis precise control and multi-axis cooperative control. In the X-Y moving platform, the closed-loop stepper motor system is adopted for each axis to obtain precise speed and position control. On the other hand, the cooperative control between modules is realized by event-based control method which uses a time-independent parameter to avoid the uncertain time-delay. To verify the system, the corresponding experiments are taken. And the results satisfy the requirements very well.

A simplified hybrid force/position controller method for the walking robots

Robotica ◽  
1999 ◽  
Vol 17 (6) ◽  
pp. 583-589 ◽  
Author(s):  
Jun Song ◽  
K.H. Low ◽  
Weimiao Guo
Keyword(s):  
Inverse Dynamics ◽  
Position Control ◽  
Control Method ◽  
Control Policy ◽  
System Stability ◽  
Estimation Methods ◽  
Walking Robots ◽  
Precise Control ◽  
Position Controller ◽  
Identification Model

Force and position sensors have been widely used in robots to realize compliance and precise control. Traditional force/position control methods were studied and developed by the inverse dynamics for decades. Generally speaking, the controller contains two parts: One is the error-driven part that guarantees system stability; another is the identification model of inverse dynamics that can compensate for system influence. In practical control engineering, a system inverse dynamics or its identification model is not easy to obtain, even when using nonlinear estimation methods. Moreover, the complicated control algorithm cannot be implemented in on-board microprocessors because of the limited speed and memory. Thus, a simplified control method using a forward system model is introduced in this paper. Since the direct dynamics of the system can be more easily obtained than the inverse dynamics, this, in turn, simplifies the control structure and increases control speed. Therefore, the proposed control policy has a wider practical application.

scholarly journals Backstepping Sliding-Mode Control of Piezoelectric Single-Piston Pump-Controlled Actuator

Actuators ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 154
Author(s):  
Bin Wang ◽  
Pengda Ren ◽  
Xinhao Huang
Keyword(s):  
Sliding Mode Control ◽  
Position Control ◽  
Control Method ◽  
Sliding Mode ◽  
Piezoelectric Pump ◽  
Mode Control ◽  
Control Precision ◽  
Backstepping Sliding Mode Control ◽  
Actuator System ◽  
The Mathematical Model

A piston piezoelectric (PZT) pump has many advantages for the use of light actuators. How to deal with the contradiction between the intermittent oil supplying and position control precision is essential when designing the controller. In order to accurately control the output of the actuator, a backstepping sliding-mode control method based on the Lyapunov function is introduced, and the controller is designed on the basis of establishing the mathematical model of the system. The simulation results show that, compared with fuzzy PID and ordinary sliding-mode control, backstepping sliding-mode control has a stronger anti-jamming ability and tracking performance, and improves the control accuracy and stability of the piezoelectric pump-controlled actuator system.

Register control of roll-to-roll gravure-offset printing equipment considering time difference between measurement and actuation

2012 ◽  
Vol 226 (11) ◽  
pp. 2726-2738 ◽  
Author(s):  
Chung Hwan Kim ◽  
Ha-Il You ◽  
Seung-Hyun Lee
Keyword(s):  
Measurement System ◽  
Position Control ◽  
Printed Electronics ◽  
Control Method ◽  
Axial Direction ◽  
Time Difference ◽  
Offset Printing ◽  
Drying Time ◽  
Roll To Roll ◽  
The Web

The manufacture of printed electronics by roll-to-roll printing machine requires more accurate register performance than conventional media printing technology. Moreover, high drying temperature and long drying time to sinter the inks can induce the substantial changes in the length of the substrate and consequently register errors. Among the roll-to-roll printing methods, the gravure one, despite its relatively fast productivity and fine-line printing capacity, has difficulty in achieving the required register specifications for printed electronics because of the dependence of the register control on web dynamics. This study proposes a roll-to-roll gravure-offset printing equipment, including the register measurement system designed to enhance register performance and the related register control method for the application of printed electronics. Each cylinder constituting the printing unit is driven independently by an individual servomotor. Moreover, the printing patterns of the plate cylinder can move in the axial direction by position control, as well as in the web transport direction by a phase shift of the plate cylinder, without affecting the dynamics of the web. The time difference between the measurement and the actual control action is considered and modeled. The register measurement system, including selections of sensors and marks is also proposed to consider the effect of the time difference. The simulation results and the experiments of the register control are shown to verify the effect of the time difference on the control performances. It is found that a proper estimation of time difference should be obtained in order to guarantee more accurate and stable control performances.

The Lower Extremity Exoskeleton Coordinated Control Method Based on Human Electromechanical Coupling

2012 ◽  
Vol 220-223 ◽  
pp. 1012-1017
Author(s):  
Qing Guo ◽  
Dan Jiang
Keyword(s):  
Lower Extremity ◽  
Electromechanical Coupling ◽  
Position Control ◽  
Control Method ◽  
Angular Displacement ◽  
Stability Margin ◽  
Hydraulic Cylinder ◽  
Load Force ◽  
Hydraulic Cylinders ◽  
Coupling Characteristics

This paper has introduced electromechanical coupling characteristics in the lower extremity exoskeleton systems, considered model ,according to legs supporting gait when people walking, established the load torque compensation model , and a mathematical model of knee position control system which is made of the servo valve, hydraulic cylinders and other hydraulic components, designed hydraulic cylinder position control loop in case of existing load force interference compensation, and used the method of combining the PID and lead correction network for frequency domain design ,ensured system to meet a certain stability margin. The simulation results show that this position control method can servo on the knee angular displacement of normal human walking, reached a certain exoskeleton boost effect, at the same time, met the needs of human-machine coordinated motion.

Time-Optimal Coordination Control for the Gear-Shifting Process in Electric-Driven Mechanical Transmission (Dog Clutch) without Impacts

2020 ◽  
Vol 9 (2) ◽  
pp. 155-168
Author(s):  
Ziwang Lu ◽  
◽  
Guangyu Tian ◽  
Keyword(s):  
Control Strategy ◽  
Position Control ◽  
Control Method ◽  
Synchronization Control ◽  
Mechanical Transmission ◽  
Coordination Control ◽  
Optimal Position ◽  
Drive Motor ◽  
Time Optimal ◽  
Optimal Coordination

Torque interruption and shift jerk are the two main issues that occur during the gear-shifting process of electric-driven mechanical transmission. Herein, a time-optimal coordination control strategy between the the drive motor and the shift motor is proposed to eliminate the impacts between the sleeve and the gear ring. To determine the optimal control law, first, a gear-shifting dynamic model is constructed to capture the drive motor and shift motor dynamics. Next, the time-optimal dual synchronization control for the drive motor and the time-optimal position control for the shift motor are designed. Moreover, a switched control for the shift motor between a bang-off-bang control and a receding horizon control (RHC) law is derived to match the time-optimal dual synchronization control strategy of the drive motor. Finally, two case studies are conducted to validate the bang-off-bang control and RHC. In addition, the method to obtain the appropriate parameters of the drive motor and shift motor is analyzed according to the coordination control method.

scholarly journals Robust Adaptive Neural Cooperative Control for the USV-UAV Based on the LVS-LVA Guidance Principle

2022 ◽  
Vol 10 (1) ◽  
pp. 51
Author(s):  
Jiqiang Li ◽  
Guoqing Zhang ◽  
Bo Li
Keyword(s):  
Cooperative Control ◽  
Position Control ◽  
Path Following ◽  
Dynamic Surface Control ◽  
Basic Function ◽  
Compact Set ◽  
Control Input ◽  
Dynamic Surface ◽  
Robust Adaptive ◽  
Event Triggered

Around the cooperative path-following control for the underactuated surface vessel (USV) and the unmanned aerial vehicle (UAV), a logic virtual ship-logic virtual aircraft (LVS-LVA) guidance principle is developed to generate the reference heading signals for the USV-UAV system by using the “virtual ship” and the “virtual aircraft”, which is critical to establish an effective correlation between the USV and the UAV. Taking the steerable variables (the main engine speed and the rudder angle of the USV, and the rotor angular velocities of the UAV) as the control input, a robust adaptive neural cooperative control algorithm was designed by employing the dynamic surface control (DSC), radial basic function neural networks (RBF-NNs) and the event-triggered technique. In the proposed algorithm, the reference roll angle and pitch angle for the UAV can be calculated from the position control loop by virtue of the nonlinear decouple technique. In addition, the system uncertainties were approximated through the RBF-NNs and the transmission burden from the controller to the actuators was reduced for merits of the event-triggered technique. Thus, the derived control law is superior in terms of the concise form, low transmission burden and robustness. Furthermore, the tracking errors of the USV-UAV cooperative control system can converge to a small compact set through adjusting the designed control parameters appropriately, and it can be also guaranteed that all the signals are the semi-global uniformly ultimately bounded (SGUUB). Finally, the effectiveness of the proposed algorithm has been verified via numerical simulations in the presence of the time-varying disturbances.

scholarly journals Integrated Guidance and Control of Multiple Interceptors with Impact Angle Constraints Considered

2019 ◽  
Vol 37 (2) ◽  
pp. 273-282
Author(s):  
Xiang Liu ◽  
Xiaogeng Liang
Keyword(s):  
Cooperative Control ◽  
Control Algorithm ◽  
Control Method ◽  
Impact Angle ◽  
Dynamic Surface ◽  
Guidance And Control ◽  
Integrated Guidance And Control ◽  
And Control ◽  
Impact Angle Constraint ◽  
Distributed Cooperative Control

To solve the multi-interceptor coordination problem and to intercept the target with impact angle constraint, a novel distributed cooperative control algorithm with impact angle constraint based on integrated guidance and control is proposed. First, the mathematic model of integrated guidance and control is established by combining the interceptor-target relative motion model with the dynamic equation of the interceptor on pitch plane. The time varying gain extended state observer is developed to estimate and compensate the unknown disturbance. Based on the estimated value and fast nonsingular dynamic surface sliding control method, the IGC algorithm of leader is given; Then, based on distributed cooperative "leader-follower" model, the cooperative control strategy of multi-interceptor is designed, and gives out speeds in two directions on pitch plane, which are transformed to the command of total velocity and trajectory angle based on kinematic relations. Finally, to control the follower, the time varying gain extended state observer and the dynamic surface sliding control method are adopted. The simulation results demonstrate the effectiveness of the distributed cooperative control algorithm.

Sign in / Sign up

Export Citation Format

Share Document