Intelligent Control Grant Agreement No LLP UK-LEONARDO-LMP Project acronym: CLEM Project title: Cloud services for E-Learning in Mechatronics Technology

Chapter 5: Implementation of numerical control Grant Agreement No LLP UK-LEONARDO-LMP Project acronym: CLEM Project title: Cloud services for E-Learning in Mechatronics Technology

Contents of Chapter 5  Control engineering  Modelling and calibration  Simulation and adjustment  Implementation tests  Simulation  Simulation methods  Precision and simulation validity  Interface with the process  Acquisition of the accessible outputs of the process  Generation of process controls (controllable inputs)  Computer  Microcontroller  Industrial controllers

Mechanic Electrotechnic Electronic Computer 1 Control engineering - Components

Objectives (Specifications) Simulation (Real ) (Virtual) Mechanical design Electronic design Automation design Mechanical implementation Electronics implementation Computer implementation Utilization (Real) Concurrent Engineering Integration 1 Control engineering - Approach

 Numerical regulation of speed  Control objectives o Have the motor operating at a given rotational speed (set point) o Maintaining the speed value although load variations (perturbation)  Expected performances of the control o Response time ( delay from the step set point to the response at 95%) o Overtaking (amplitude of consecutive oscillations around the step) o Static error (permanent gap between the set point and output) o Dynamic error (fluctuations due to a perturbation )  Components o DC motor o Power amplifier (or a chopper) o Computer micro system Processor and associated circuits Electronic converter 1 Control engineering - Objectives

 DC motor equations  Integral form for model building o Transfer function of the linear amplifier (or of linearized chopper) o Linear electric equation of the DC motor o Linear electro mechanic equations of the DC motor o Linear mechanical equation o Non linear mechanical equation 1 Control engineering - Modelling

 Simulation result analysis Influence of the dry friction on the step response in open loop control Without incidence on the response to small jumps of the set point Modification of the permanent response due to a step input 1 Control engineering – Simulation results

 Model with the control  Analogical Numerical Converter (Digitizer)  Numerical Analogical Converter (ZOH)  Numerical PID Proportional Integral Derivative Speed Set point Converter Numerical  Analogical Converter Analogical  Numerical Perturbation Torque Torque measure Speed measure Speed plot Power & DC Motor Control 1 Control engineering – Simulation closed loop

 Adjustment of the PID corrector  Initialisation with calculated parameters  Performance analysis  Parameter refining in order to compensate approximations  Robustness study  Perturbation compensation  Acceptable performance degradation o Modification of frictions (wear / maintenance ) o Modification of electrical characteristics of the motor ( R function of the temperature )  Validation of the electronic dimensioning  Choice of the precision of converters  Determination of signal amplitudes ( amplifier current / motor)  Verification of mechanical dynamic constraints 1 Control engineering – Exploitation

 Analysis of the closed-loop response Rapid response to a set point modification Weak sensitivity to load variation Influence of the derivative gain on damping and speed 1 Control engineering – Adjustment

 Adjustment of the corrector Influence of the derivative gain on damping and speed Insufficient Kd Too high Kd Convenient Kd + 5 % 1 Control engineering – Adjustment of Kd

 Progressive introduction of hardware (Hardware In the Loop)  Amplifier, motor and sensor of the final system o Real characteristics  Generic calculator o Simultaneous development of software and hardware o Simplified test from modelling environment (Simulink)  Implantation of final system  Final microcontroller o Real characteristics  Link conserved with the development calculator o Test from modelling environment (Simulink)  Generation of the final version of the software  Code optimization 1 Control engineering – HIL

 Automatically generated code from the model  Example : parameters and code of state corrector model I This C++ code is only generated to produce the executable code for HIL tests 1.0, /* Intgral_A : ' /Integral' */ 1.0, /* Intgral_B : ' /Integral' */ 0.6, /* Intgral_C : ' /Integral' */ Ki 0.6, /* Intgral_D : ' /Integral' */ Ki /* DiscreteZeroPole Block: /Integral */ { static real_T xnew[1]; xnew[0] = MCC_BF_P->Intgral_B*MCC_BF_B->ek; xnew[0] += MCC_BF_P->Intgral_A*MCC_BF_DWork->Intgral_DSTATE; (void)memcpy(&MCC_BF_DWork->Intgral_DSTATE, xnew,sizeof(real_T)*1); } /* DiscreteZeroPole: ' /Integral' */ { rtb_r64_temp21 = MCC_BF_P>Intgral_D*MCC_BF_B->ek; rtb_r64_temp21 += MCC_BF_P->Intgral_C*MCC_BF_DWork->Intgral_DSTATE; } 1 Control engineering – Generated code

Analogical Numerical Converter Numerical Analogical Converter Processor Memory Amplifier Analogical Filter Amplifier Chopper  Control system  Calculator (Processor, memory and management circuits)  Links with the process o Input and output circuits (ANC and NAC for analogical systems) o Shaping of signal (Amplification, Multiplexing, Protection, Filtering) o Amplification du signal (Power amplification, Pre actuation) 1 Control engineering – Hardware

Processor Memory Management circuits Real Time Operating System Code of the application Timer T  Control software implemented in computer controller  Real Time Operating System (Lab: Real-Time Windows Target )  Software application (Lab: generated by Real-Time Workshop) Management I/O I O ANC NAC Real time clock Control timing Communication with the process 1 Control engineering – Software

 Control algorithm  Routine launched at each period T o Enter the measure of speed wdt [k] o Calculate the error e [k] = wdtRef [k] – wdt [k] o Calculate the proportional correction up [k] = Kp * e [k] o Calculate the integral correction ui [k] = Ki * [ xi [k] + e [k] ] o Calculate the derivative correction ud [k] = Kd * [ ̶ xd [k] + e [k] ] o Calculate the control u [k] = up [k] + ui [k] + ud [k] o Output the control u [k] o Calculate the integral state xi [k+1] = xi [k] + e [k] o Calculate the derivative state xd [k+1] = e [k]  Timer trigger o Timer programming o SETR query to associate routine The [k] index is visualized for understanding but not useful to conserve in memory 1 Control engineering – Algorithm

 Control generated by the computer controller The control is modified at each period and maintained constant during the period If computation time isn’t negligible the control can be applied with a delay of one period which can be compensated with a predictor 1 Control engineering – Control