Article: Four Parameters, Not One: The Control System Explained
Four Parameters, Not One: The Control System Explained
Four Parameters, Not One.
How Direct Torque Measurement Changes Commissioning.
How Roger's Field-Oriented Control architecture expands obstacle detection from a single sensitivity threshold to four independent parameters — and what that gives the installer at the commissioning screen.
If you've read Inside a Roger Brushless Motor, you already know the hardware: a permanent-magnet brushless motor, a four-quadrant MOSFET inverter, a digital controller running Field-Oriented Control, and native rotor feedback. This article picks up at the next layer. The hardware is the foundation — the control architecture built on top of it is what the installer actually touches at commissioning, and where Roger diverges most clearly from the rest of the installed base.
Forty Years of Inferring Load
Gate automation has, for four decades, been built on a single sensing principle: infer load from current draw on the supply line. When the gate meets resistance, the motor draws more current, the controller sees the rise, the supply is cut. The installed base of single-phase AC capacitor-start operators and low-voltage brushed DC operators all work this way, and the approach is mature and reliable.
Its limitation is structural, not a defect. Supply-line current is an indirect measurement of motor behaviour — affected by motor temperature, capacitor age, brush wear, gearbox grease condition and ambient temperature. The measurement sits several layers removed from what is actually happening at the rotor.
One adjustable parameter — a trip threshold against an averaged current signal. More parameters would not help, because the underlying signal cannot carry more information.
Four independent parameters — torque, sensitivity, reversal time and reversal distance. Each addresses a different physical property of the installation.
This is good engineering for the electronics available at the time. It is also where the architecture has remained.
Measured at the Motor, Every Millisecond
The Roger brushless platform measures motor torque directly through Field-Oriented Control — the same control strategy used in electric vehicle traction motors, industrial servo drives and high-end CNC spindles. FOC mathematically decouples the motor's torque-producing current vector from its magnetising current vector and controls each independently. The DSP reads torque at the motor itself, in real time, every millisecond.
This is not a feature stacked onto the old architecture. It is a different category of measurement, and it makes a different category of control available at the commissioning screen.
“The controller is not inferring load from the supply line. It is reading torque at the motor — a thousand times a second.”
What Appears on the Commissioning Screen
The torque the DSP commands under normal operation, held constant across the speed range by FOC. Set at commissioning to match the application — high enough that the gate moves cleanly against its specified maximum load, and no higher. Because torque is directly controlled rather than a side-effect of motor sizing and supply voltage, it can be specified as a number on the display.
How far measured torque may deviate from the setpoint before the controller declares an obstacle. Critically, it is independent of working torque — so the controller tolerates sustained variation like wind pressure on a leaf, while still reacting sharply to a transient step change like an obstruction. Supply-current systems cannot make that distinction: one threshold, one averaged signal, no architectural way to separate sustained load from sudden load.
How long the gate runs in reverse after detecting an obstacle. Short for clearance, longer where the obstruction may need space and time to be removed.
How far the gate physically moves during the reversal — millimetres on a slider, degrees on a swing, not seconds of motor runtime. Available because the controller knows rotor angular position directly through native encoder feedback, resolving to better than 0.1° on sensored models. On time-based systems, “reverse for half a second” means different physical distances at different speeds, temperatures and battery voltages.
The working torque setpoint is also the ceiling on the force the gate can apply at the moment of impact. On supply-current systems that ceiling is whatever force the motor happens to develop during the detection lag — typically uncontrolled. On Roger, it is a number the installer chooses.
Same Hardware, Different Parameter Set
1,200kg slider, 22m/min, north-westerly exposure with afternoon gusts, worked all day.
Torque — application-matched, sized to drive the leaf cleanly under specified maximum wind load, no more.
Sensitivity — tolerant of sustained deviation. Wind reads as load, obstruction reads as fault.
Reversal time — short. Quick recovery for the next vehicle.
Reversal distance — short. Clear the path, don't interrupt the cycle.
320kg per leaf, thirty cycles a day, sheltered site.
Torque — application-matched. A light leaf in a sheltered position, lower than the commercial setpoint.
Sensitivity — tight on transient deviation. Any sudden resistance triggers an immediate reverse.
Reversal time — longer. Generous pull-back.
Reversal distance — longer. Unambiguous clearance.
The commissioning display: four values the installer sets, records and reuses.
Same operator, same controller, same firmware. Different commissioning profiles. The hardware does not change — the parameter set does.
Four Parameters, On Site
The shift from indirect to direct measurement, and from one parameter to four, produces four concrete outcomes in the field.
Parameters are discrete numerical values. Once you have the right set for a gate class, those numbers become the starting point for every comparable site. Trial-and-error converges to a personal commissioning library, and each job gets faster than the last.
The four parameters map to four things you can show the customer: how decisively the gate moves, how it reacts to something in the path, and how much room it gives once it has reacted. The conversation moves from “trust me, it's set correctly” to a visible, repeatable demonstration — which is what supports the premium quote.
Digital parameters do not drift. Behaviour commissioned on day one is behaviour delivered in year ten — no analogue trimpot wandering with temperature, no capacitor ageing, no clutch glazing. Call-backs happen because the application changed, and the fix is a parameter adjustment rather than a mechanical rebuild.
Across the operator's working life the commissioning record is the operating state. New conditions do not require new hardware — just a parameter review. This is the foundation of Roger's true 100% duty cycle rating and Edgesmith's warranty position.
The Part a Spec Sheet Never Shows You.
Two operators can carry the same weight rating, the same duty cycle and the same protection rating, and behave nothing alike on site. The difference shows up at commissioning, and again on the third service visit, and again in year ten — long after the specification comparison has been filed away.
That is why we write these articles. Four parameters where the architecture used to support one is not a feature increment — it is a different category of control over how the gate behaves, set the day it is installed and held there for the life of the operator. Installers who understand why it works can specify it with confidence and defend the quote.
We don't simply resell a brand. We choose components we can stand behind technically, and we explain them properly so installers and specifiers can make informed decisions.
— The Edgesmith Team
Part 02 — Why Position Beats Time. How native encoder feedback holds slowdown zones to the millimetre across thousands of cycles, and why the slowdown phase on time-based systems drifts every season.