Stepping motors are everywhere in the hobby robot project: If you make robots or automation projects today, you are likely to use them. Almost all DIY projects from 3D printers and CNC milling machines to air hockey and juggling robots are used. However, in the field of industrial automation, the brushless servo motor has been taken, and it is clear why: they don't lose the stairs, more powerful, more efficient, and more quiet.
However, brushless motors are not unique to expensive industrial automation equipment. In fact, you can purchase some powerful and low-cost motors in the amateur hobby store. Driving these motors is also very cheap. So how do you use them if there is any non-industrial automation system?
To be true, a driver allowed to be present should be existing. But since there is no, I decided to do one. This project is the opening source of hardware and software, and warmly welcomes any people who want to join.
Main specifications:
Two motor channels are designed for > 100A peak current.
1 DC-DC Converter Channel
- Power supply to the system using any voltage power supply, or
- use brake resistors
24V bus voltage
USB, CAN, UART, PWM and step / DIR interface (see below)
Encoder feedback for any precise movement
Support power regeneration
Using high-power density lithium batteries means that only one moderate power supply can be realized. 1882. 1 kW peak power output.
It will have a variety of best control policies and motion profiles.
Licensing licenses on hardware and software: You can use this item in any of your favorite projects, or even commercial products (as long as you are attributable to the contributor of the project).
interface
USB serial port - PC, BeagleBone, RaspberryPi, etc.
Can-canopen and CIA 402 are possible
UART - Arduino, Mbed, etc.
PWM - RC receiver, Arduino, etc.
Step / direction - existing motion controller
Some universal numbers and simulation pins
protocol
G code parser for connecting with existing automation tools
Many types of command patterns
- Go to (position control of trajectory planning)
- position command
- Speed Command
- Torque command
structure
Be
The drive is intended to provide an incredible high peak power, each motor channel exceeding 1KW. However, it is expensive to provide this power supply. Moreover, when the actuator decelerates, the energy is absorbed. Most power do not like to turn energy back.
Solution: Place the high-power energy storage device on the DC bus. A battery like this can provide approximately 3 kW of electricity. These types of batteries also have a relatively high charging rated value, and if regeneration exceeds only a few hundred milliseconds, they may handle more than the specified. Therefore, they should be able to handle all regenerative power in most robot applications.
This means that we have a variable voltage DC bus, fluctuating with the battery's charging state. Therefore, we supply power to the system through a DC-DC converter. There is also another benefit: We can use any voltage power supply, just convert it to the bus voltage. I hope most people will use inexpensive ATX power supplies (especially 12V rails). In many robot applications, exercise consists of several discrete motions, only some of them are high power. In this case, we can get very high peak power, but only a very moderate power supply.
Another advantage of using a battery stabilizing the DC bus is that if multiple of these drives are on the same bus, they do not affect the regulation of the bus voltage: a single board can be connected to a PSU in the DC-DC, other panels in the system A bus can be used. In fact, you can even skip the DC-DC on the slave plate.
The system can also use brake resistors to dump regenerative energy rather than batteries to absorb it. This is a simpler and prolonged setting, too. The item will be used in the first instance until the battery storage function is ready.
application
So this project is good for some things, but not everything.
You should use this drive in the project if:
Requires high power: each channel. 1882. 1kw peak power!
High precision: Encoder feedback control means that accuracy is as high as the accuracy of the encoder, can be very high.
Requireability: Encoder feedback ensures that the drive is restored from the positioning error: no longer missed any steps.
In the following cases, this drive should not be used in the project:
High torque is required, but don't care, and you don't want to use any transmission. If this is the case, the stepper may be more suitable for your project.
If you are interested in very small motors, then you should check these superb mini robots!
If you need industrial-grade motor reliability and rugibility, you should not use a hobby motor. However, drive electronic devices and software should be reliably operated during maturity.
Be
Source: HackADAY.IO
The original content of the circuit city is not allowed to reprint!
Board evaluation cooperation mailbox:
[email protected]
Our other product:
