DIY Lawnmower 2023: Difference between revisions

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[[File:Lawnmower2023 rotaryAngle distance.svg|thumb|Use distance sensor to detect the angle]]
[[File:Lawnmower2023 rotaryAngle distance.svg|thumb|Use distance sensor to detect the angle]]
The angles needed are:


The motion of steering is restricted, thus the angle need to be measured. Two easy options:
The motion of steering is restricted, thus the angle need to be measured. Two easy options:
Line 27: Line 29:


'''Distance sensor HC-SR04'''
'''Distance sensor HC-SR04'''
* Dependent on temperature.
* Dependent on ambient temperature.
* Ping rarely so that no echoes.  
* Ping rarely so that no echoes.  
* [https://forum.arduino.cc/t/hc-sr04-tests-on-accuracy-precision-and-resolution-of-ultrasonic-measurement/236505/11 Tests on accuracy]
* [https://forum.arduino.cc/t/hc-sr04-tests-on-accuracy-precision-and-resolution-of-ultrasonic-measurement/236505/11 Tests on accuracy]


'''Single track gray code'''
'''Single track gray code'''
* Accuracy:
*


=== Wheels and tires ===
=== Wheels and tires ===

Revision as of 09:21, 13 June 2023

Introduction

2 wheel drive using kids ATV chassis with 3" wheels without differential but with steering, 2x350W motor; speed controller. The grass cutter is a part from an old lawn mower. The ATV is steerable, thus a rotation measurement device is needed so that the motor will not burn.


https://www.kuldnebors.ee/search/search.mec?pob_action=search&search_O_string=atv&search_source=kwc

Arduino + GPS + IMU (Differential GPS).


Consider also

Theory

Steering

Use distance sensor to detect the angle

The angles needed are:

The motion of steering is restricted, thus the angle need to be measured. Two easy options:

  1. Use distance sensor (HC-SR04), or
  2. Use rotary encoder (single track gray code)

Add the limit sensors to both.

Distance sensor HC-SR04

Single track gray code

  • Accuracy:

Wheels and tires

Using an old kids ATV; 3" wheels; too small for pushing the snow, but perhaps enough for the first project.

Cheap axis:

Ulkohalkaisija täynnä noin 36cm (6")

Current

Heat Dissipation

Motor

Torque, Speed, Duty Cycle

Vevor 24V 350W Nennstrom: 18,4A Brushed Permanentmagnetmotor Gear Reduction Packungsgröße: 22 x 19 x 17 cm (8,66 x 7,48 x 6,69 Zoll) Bruttogewicht: 3,05 kg 


   410-9T Kettenrad

9 Zahnrad für Kette Nr. 410, Teilung 12,7 mm. Besonders gut für Heimwerker geeignet, da der Antrieb mit Standard-Fahrradketten (1/2 Zoll Teilung) kompatibel ist

Motor Speed Controller BTS7960

We use BTS7960 based speed controller with max 43 Amps current. The datasheet is available at https://electropeak.com/learn/download/bts7960-43a-motor-driver-datasheet/

Example code from https://electropeak.com/learn/interfacing-bts7960-43a-high-power-motor-driver-module-with-arduino/

Pins

  • VCC: 5V
  • GND: Ground
  • IS-R: Input signal for detecting high current – Straight rotation
  • IS-L: Input signal for detecting high current – Inverse rotation
  • EN-R: Output Signal for controlling motor direction – Straight rotation
  • EN-L: Output Signal for controlling motor direction – Inverse rotation
  • WM-R: PWM Signal for controlling motor speed – Straight rotation
  • PWM-L: PWM Signal for controlling motor speed – Inverse rotation

Motor pins (High current):

  • M+: Motor Positive; M-: Motor negative
  • B+: Battery positive; * B-: Battery negative


Some instructions:


Extra things and older thoughs.

Use PWM. Feedback? Arduino L298N H-bridge.

Arduino pwm motor controller 300W 36V 20Amps


https://electropeak.com/learn/interfacing-bts7960-43a-high-power-motor-driver-module-with-arduino/

High power dc motor speed controller

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