FAQ STEVAL-ESC001V1 – updated 01/06/2018

Document created by Matteo Maravita Employee on Jun 1, 2018
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Q1 - May I connect the ESC directly to a FCU and spin the motors immediately? Or should I write or customize the FW code?

A1 - The FW must be customized using the MC ST tools. If unknown, the motor need to be profiled and saved. Open the workbench file included in the FW package of STEVAL-ESC001V1 and load the motor parameters before to generate the header files for the MC library configuration. Compile with a Compiler/Debugger tool and upload the binary into the microcontroller with an external ST-Link programmer.

  At this point the board is ready to run the motor according with the input PWM signal from the FCU board.

We strongly suggest to read the documentation related to the STEVAL-ESC001V1 board and MC FW library and eventually refer also to the videos published on Youtube.

  

Q2 - Which are main differences between STEVAL-001V1 and other commercial ESC available in the market?

A2 - The FOC (or vector control) algorithm is the key point to distinguish the STEVAL-ESC001V1 from other commercial ESC boards in the market. It is very common to find commercial ESC with more simple motor control algorithm (usually Six-Step type), that are easier to use and no need of fine tuning for each motor. On the other hand, FOC algorithm is allowing to have better efficiency and much smoother control of the motor especially in high load condition. On top of the motor control performance, there is the possibility to customize the FW in order to support several communication ports (like for example CAN used in Professional Drone systems), giving more flexibility to the user.

 

Q3 - May I use the ESC up to 40A?

A3 - By default the max peak current availability is 30A. If more current is requested, the shunt resistors value must be reduced and the FW configured to support it.

 

Q4 - What is the meaning of FOC? Which is the benefit compared to other control algorithms? Which are the drawbacks?

A4 - FOC is the acronym for Field Oriented Control: Stator currents (Field) are controlled in amplitude and phase (Orientation) with respect to rotor flux.

 

Benefits of FOC compared to standard 6-step control:

  • Better energy efficiency even during transient operation, due to optimal current angle, especially in case of high current load conditions.
  • More responsive speed control to load variations, due to direct and decoupled control of electromagnetic torque and flux. It allows to have higher acceleration and deceleration without losing control of the motor.
  • Less motor vibration due to sinusoidal motor current waveforms and optimized control. Less vibration is also related to reduced acoustic noise from motor and higher efficiency of propeller use.
  • Less battery consumption related to higher efficiency, especially in case of high load conditions.

 

Drawbacks of FOC compared to standard 6-step control:

  • More complicated algorithm, need a learning curve for engineers approaching it for the first time. In case of the STEVAL-ESC001V1 the GUI is hiding this complexity but still need some study for parameters tuning.
  • Motor parameters are needed in order to can control the motor. The Motor Profiler tool inside the Motor Control Workbench helps by automatically calculating the needed parameters (beside the pole pair number). It’s needed to repeat this fine tuning procedure (and so update ESC FW) when motor is changed.
  • Need ESC FOC PID fine-tuning also when propellers are changed. The Motor Profiler is helping by automatically calculating also dynamic properties of motor+propeller and changing PID settings accordingly.

 

Q5 - Do I need to customize the FW for each motor or propeller?

A5 – Yes, the FOC usage requires the FW customization for each pair of motor and propeller.

 

Q6 - Is the ESC accepting DShot, Multishot, ... protocols?

A6 - The STEVAL-ESC001V1 is capable to HW support faster protocols as DShot, Multishot etc., but they are not implemented in the official FW project release.

 

 

Q7 - Is it implemented auto calibration feature for the ESC?

A7 – No, it’s not implemented in current official FW project release. The min and max threshold for PWM input must be fine tunes in the source code.

 

Q8 - May I run BLHeli_32 FW?

A8 - No, actually the STEVAL-ESC001V1 doesn’t support the BLHeli_32 both in terms of HW and FW.

 

Q9 - How can I make the motor sounds?

A9 - It is possible to generate the sound from the motor with a PWM sequence for each motor phases. The PWM frequency and duty cycle value must be chosen to be audibled.

 

Q10 - Which is maximum speed I can achieve?

A10 - The maximum speed reachable depends by the motor and propeller choice and it is limited by the maximum current available and the bus voltage usage (Lipo battery level: 3S, 4S or 6S).

 

Q11 - Which kind of protections are implemented?

A11 - The over-current, over-voltage, under-voltage and over-temperature protections are

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