I have indeed ridden on many monorail systems, as well as maglev and multi-rail systems. So why the nasty comment? Try to address the questions posted by the TS instead of throwing stones.

The fact is that until we saw the photos we had not much hint of what the sort of system was that we were commenting about and providing advice for.

 

The University of West Virginia has or had a monorail system and I even rode on it.

https://en.wikipedia.org/wiki/Wuppertal_Schwebebahn
Used it daily when I was working in Wuppertal

 

Now it is clear as to the physical nature of the rail and the trolley that travels on it. We even saw a bit of a view of the motor driving the present version. So it is entirely possible that a similar question has been asked and some level of answer provided previously. so my comment that the track may already exist and already be in position was probably correct.
To drive this assembly with a motor similar to the one in the photo it makes the most sense that for the highest efficiency there should be some gear reduction between the actual motor and the drive wheel. The reductioon ratio should be such that with the otor at it's most efficient RPM the module speed is close to the maximum speed required.

 

I am under the impression that the track is straight.
By removing the motor from the carriage, it reduces the total weight on the track.
By placing the motor and battery stationary in one location (they can be anywhere along the length of the track) you can use a bigger motor and battery. The motor consumes zero power when stopped.

The track is straight. We did look into the options you suggested and in fact that was one of the primary designs. However, it is costlier and more involved when it comes to the installation. I actually like the idea (earlier suggested in the forum) about having a smaller battery on the carriage and have a large charger battery at any one end. this will reduce moving parts and battery weight. Also there is no incline on any side. We are thinking of stopping the motor completely on each stops. If it moves a bit for any reason, that is not going to create an issue for us since we reset the cycle after each trip.

 

The reductioon ratio should be such that with the otor at it's most efficient RPM the module speed is close to the maximum speed required.

Thank you. This was my next question going to be in the forum - choosing the right reduction ratio. It appears that we will need to try a few different ones to identify the most suitable gearbox and reduction ratio.

 

The higher the ratio, the less load on the motor, the gearing has to support the desired rate of movement when the motor is ran at the optimum RPM.

 

For each spur-gear pair there is some friction, and thus power waste. So the loss in gear reduction efficiency increases i steps as the number of stages increases. So the loss that way needs to be considered. And greased gears usually have more losses than oil lubricated gears, at reasonable speeds.
Probably the desired travel speed is known, as well as the resulting drive wheel RPM. Probably the required driving torque can be reasonably guessed, and at a constant speed, compression of the drive wheel material will be the main unknown variable. The rolling friction should not be very much, but that is the other loss. The BLDC motor package will have speed/torque, current curves, and so the best speed for the estimated load power can be seen.
Standard gearboxes for small motors usually have a list of available ratios, often including the number of reduction stages.
It is not likely that more than two stages of reduction will be required. So it should be that a range of ratios will be available that will include one that provides a reasonable motor speed with the desired travel rate.

 

And make sure to support the output shaft with a good bearing as close to the friction wheel as possible.
Integrated DC gearmotors are not known for being good with shaft side-loads, the output shafts often have bronze sleeve bearings that will eat much mechanical power if side-loaded.

 

Thanks you everyone for your time and support. As we start, we have decided to include charging dock, rfid reader and dc gear motor. In time I'll let you know updates once progress through the design. All inputs have made a great difference for us. Big thank you.