How to build simple analog balancing robots

[29riteshkakkar]

Cool work.............

nice work!!

[MrBarcode]

Can this be scaled up to a DIY Segway?

[roboanalogtom]

@MrBarcode Sure but you'd have to use different sensors such as gyros and accelerometers.

[roboanalogtom]

google "modify servo for continuous rotation" and they'll be lots of websites that show you how to do it.

[sagar2880055]

nice one !! im a amateur,tyrin to make it for a science fair, can i know how to convert the servo in to a continuosly rotating one

[silverstream314]

Very nice! Is there any way to increase the stability, as to make it able to recover from nastier pushes, etc.?

[roboanalogtom]

@silverstream314 Yeah, if one used accelerometers and/or gyros instead of LDRs then you can increase stability. Also, using an active PID instead of a passive PID set up would also increase stability since it would be easier to tune the behavior.

I was happy just to get such a simple circuit to stay up!

[silverstream314]

@roboanalogtom Yes, all balancing robots I've seen uses accelerometers and gyros, and that made me very impressed to see such a simple circuit managing the same thing (and the clever use of photoresistors)! So an integrating part would help? I was under the impression that integrators were mainly used to correct for constant offsets, which can't really be present in this kind of application as the robot would then fall.

[roboanalogtom]

@silverstream314 You're right. In this set up there's a sweet spot in relation to the light where the robot is stable so in this specific case integrating likely would not help.

[silverstream314]

@roboanalogtom Okay, so at least I'm not completely off. How sensitive is the robot to changing light conditions?

[roboanalogtom]

@silverstream314 It's very sensitive to changing light conditions although I haven't built one and actually moved the light source.

[brainsgowalking]

Awesome, and congrats on winning the 555 contest!!!

[brsild]

is it possible to use ir emitters instead of ldr's for this bot?

[roboanalogtom]

@brsild I'm going to go ahead and quote myself from last week: "I don't see why a wide range of sensors couldn't be used.....For certain sensors an op amp may have to be used instead of just a passive PD setup, though.".

[brsild]

do u know where i can find the schematics for for an analog balancing robot that uses ir sensors

[roboanalogtom]

@brsild No but I'd use the Sharp range finder IR sensors. You'll only need one. I got a single transistor balancing robot to work with the Sharp sensor (it's a short vid posted in my account, it had to keep moving forward to maintain balance and the mosfet transistor was used in linear mode and was only stable for a 20-25 foot run).

I've seen vids of balancing robots that use two simple IR sensors but I don't recall any done purely in analog.

Try googling "Dale's homemade robots".

[brsild]

is there a way to adapt two ir sensors to this? (btw nice build) 

[roboanalogtom]

@brsild I don't see why a wide range of sensors couldn't be used such as accelerometers. For certain sensors an op amp may have to be used instead of just a passive PD setup, though.

[DrZeibenstein]

well done in the 555 contest

[eddythejekyll]

Ingenious!

[raggzor]

From a control engineer, ingenious ;)

[westfw]

That's wonderful! Great use of the features inherent in the modified servo, and in the 555, and simple enough that it really highlights the principles that make it work, plus it looks like anyone could make one! Good luck in the 555 contest; it seems to me that this is exactly the sort of circuit they were hoping to find!

[solidacid1337]

great video, everything was familiar an well explained. good job :D

[theskaneesh]

can u pls make tutorial on building a simple robot

it can be a 1.beetlebot 2.light seeking robot 3.line following robot or anything

[megamuppen921]

robot, play dead! BANG! dead...... 04:25

[phantuanp4t]

Very interesting and smart!! However I have 1 concern about the light source. You set 2 light sensors 92deg relatively to each other. What is this for? Only for the case of having 1 light source environment, isn't it? Can this robot work in a normal office, where many lights are above us?

[phantuanp4t]

Very interesting and smart!! However I have 1 concern about the light source. You set 2 light sensors 92deg relatively to each other. What is this for? Only for the case of having 1 light source environment, isn't it? Can this robot work in a normal office, where many lights are above us? 

[phantuanp4t]

Very interesting and smart!! However I have 1 concern about the light source. You set 2 light sensors 92deg relatively to each other. What is this for? Only for the case of having 1 light source environment, isn't it? Can this robot work in a normal office, where many lights are above us?

[MrKinochi]

his cool maker

[budsiskos]

could this be use with two servos for a segway style?

[smclane6]

Nice instructional video! I am planning to do a similar build with two wheels.

[adrianwwwa]

Great project. Inspired me to try one myself, but using an op amp (derivative connection) and a low g accelerometer (1.5g). I still need to find a way to get more torque at a low signal - maybe pwm will do it instead of amplitude only. I am using a dc motor. How do you get your motor to spin cw or ccw using only a 555 ic? is it a stepper motor?

[roboanalogtom]

It's a "radio controlled aircraft style" servo that's been modified for continuous rotation.

Try searching "continuous rotation servo" in Google and they'll be links of how to modify servos or where to buy them pre-modified. Parallax has modified servos selling for $13.

The 555 timer is being used as a signal generator needed for controlling the servo. If you want more torque with a small signal, you just use a smaller resistor for Pr (in the vid). This increases P gain.