More reference: FAQ 2 (frequently asked questions) about VESC controller

24 aprile 2020

1. What is VESC?

Vedder Electronic Speed Controller or VESC is an open source project, started by a Swedish engineer named Benjamin Vedder in 2014 to create a customizable high power Electronic speed control. The project was mainly tailored for the Electric skateboard, but now it can be used for many applications, such as E-Bike/Robots/Drones/Underwater propulsion system/Cable-camera/Parking system/etc.

Maytech VESC based controllers: click each picture to check specs of each VESC.

2. What is the difference of VESC4 and VESC6?

Both work good in BLDC mode.

VESC4 is basic version, working good in BLDC mode and more economic.

VESC6 has some updates in firmware and hardware for more functions and more precise control, such as:

Replacing the driver chip with the DRV8301 solves some VESC4.12 DRV error problems in FOC mode;
Independent current ADC sampling chip for faster sampling of current data;
Add one more sampling resistor to provide more accurate current data.

Here is the comparison of different VESC based controller models in our store:

3. What is VESC_TOOL?

VESC Tool development started in 2017 to create an application with a mobile version for control, customization, and update of VESC firmware. The application was created in an open source fashion, as well. The tool can be used over USB and recently through a wireless connection as well. It is developed to be compatible with latest VESC Hardware and backward compatible with older versions of the hardware. It allows the generation of real time data that can help improve performance of systems employing VESC.

Here is picture of VESC_TOOL interface:

4. What's the difference of ESC and VESC?

VESC is more advanced ESC. It's got amazing features. It's one of the latest BLDC ESCs which give you full control over how your ESC operates. Much better than typical RC ESCs. It allows tons of customization. It allows you to control the torque of the board by adjusting the current output to the motor and current input from the battery. It allows you to customize the acceleration and braking curve so that the board behaves exactly as you want it to while braking and accelerating.

You can also set some limits to protect your ESC, motor, and battery such as:

-limiting the currents to the motor. (over current to the motor fries it.)
-limits the temperature of the VESC. (going too hot may cook the VESC).
-limiting the minimum voltage to drain the battery. (over-discharge degrades the battery.)

Item	VESC	ESC
High Voltage	3-12S Lipo Voltage	2-6S Lipo Voltage
Volume	Small volume high power	Small volume low power
Compatible with brushed and brushless motor	Yes	Brushless Motor
Can work with sensored and Sensorless motor	Yes	Sensorless motor
Support PWM/ADC/UART and Canbus Signal Input	Yes	No
Support sinusoid (FOC) and square-wave to control motor	Yes	No
Applications	Electric skateboard / Mountainboard / robotics / Drones / Underwater propulsion system / Cable-camera / Parking system / etc.	Drone / Airplane / Helicopter
Support forward and backward	Yes	No
Regenerative Brake	Yes	No
Over voltage/Over current protection, low voltage protection	Yes	No
Battery Protection	Yes	No
Overheat Protection	Yes	No
Support VESC_TOOL to adjust parameters	Yes	No
Multiple VESC synchronization(speed and torque synchronization)	Yes	No

5. What is Regenerative brake?
VESC regenerative braking takes advantage of the fact that you can turn the motor into a generator of some sort. Given that the process that induces an electric current into the copper wire also induces resistance into the system, it is perfect for braking. The resistance slows down the wheels, thereby providing effective braking.

On the other hand, the electric current produced during the process is fed into the battery cells, thereby recharging the batteries.

The efficiency is influenced by your battery BMS, your using environment and also your battery capacity.

Besides VESC regenerative braking, another type of braking is the Dynamic Braking. Dynamic braking uses a different setup that the current is fed to a resistor. So, this setup includes additional components. Picture is as following:

When the VESC is instructed to brake, the kinetic energy in the wheels is spin the magnetics around the copper wire. This induces a current and some resistance, very much as is the case with regen braking. However, the electric current is diverted to a resistor where it converted to heat, thereby converting the kinetic energy to heat that is lost to the environment.

The good thing about the dynamic system of braking is that you can use the brakes even your battery is fully charges. So, if you live on the top of a hill, and the first time you hit the road with your e-skateboard is going downhill, you can use dynamic braking without destroying your battery. Additionally, dynamic braking adds a layer of redundancy to your braking capabilities, which improves the overall safety of the skateboard.

6. What is BLDC mode?

Brushless Direct Current (BLDC) mode is the conventional way that electric skateboards have been built. BLDC mode offers ease of use, reliability and high adjust ability. This mode is recommended for entry level enthusiasts. BLDC does tend to be significantly louder when operating over FOC mode.

7. What is FOC mode?

Field-Oriented Control (FOC) is used to control the AC synchronous and induction motors. FOC is a different method of spinning up the motors. It was originally developed for high-performance motor applications that are required to operate smoothly over the full speed range, generate full torque at zero speed, and have high dynamic performance including fast acceleration and deceleration.

FOC is well-known for its superior efficiency and extremely quiet operating sound. Using FOC coupled with sensors gives extreme low end torque for when you are traveling up a steep hill at low speeds.

8. What does each mode mean when use for electric skateboard? (Vesc PPM Control Modes)

Before to answer this question, let to know ‘What is Hall Sensor’ first.

Hall sensors are positioned in the motor to send rotor position information back to the ESC. Sensored brushless motor has smooth transition from slow speeds and be able to produce a great amount of torque right at zero RPM. Sensorless brushless motor is able to operate very well at high speeds.

-Sensorless mode in VESC is not to use hall sensor;

-Sensored mode is pure sensored mode, which means it’ll use sensors all the time. You probably don’t want this as sensors are not efficient at high speeds and may cause issues such as high heat.

-Hybrid mode will cut off the sensored operation at a predetermined erpm from the “sensorless erpm” field in vesc tool. So it operates in sensored mode at motor startup and in sensorless mode at high speed.

10. How to control two VESCs (two motors) synchronously by one remote? ( Connect two VESC via CAN Bus )

Vedders VESC allows the connection of multiple devices via CAN bus. You can control one (master) VESC via PPM/ADC or nunchuk and let the other (slave) VESC follow the master’s commands. You can use this for a vehicle with two or more motors to have 4wd or whatever you like. The software also allows a basic traction control feature in which it will detect the lowest spinning motor and ajust the other to match that speed.

Follow is how to do: