Tiller Pilot Question

[lockie]

I noticed the Simrad TP1/22/32 tiller pilots have Hall effect rotation sensors in the schematic, but can't see anything similar in the schematic for the Raymarine ST1000/2000.

Does anyone know the function of these sensors in the Simrads. Are they for motor stall detection?

Cheers, Graeme

[lockie]

Nobody knows?

[DeepFrz]

I thought I posted a reply but it somehow got lost in cyber space. They are heading sensors and are used in conjunction with accelerometers to control the autopilot.

[lockie]

Originally Posted by DeepFrz

I thought I posted a reply but it somehow got lost in cyber space. They are heading sensors and are used in conjunction with accelerometers to control the autopilot.

No, that is not correct. The fluxgate compass does that, and there are no accelerometers in the circuit or assembly diagrams. These devices sense shaft rotation only.

Anybody know?

[wsmurdoch]

The hall sensors appear to be counting shaft rotations. It would be a handy thing for the autopilot algorithm to know... run the motor clockwise X seconds to move the rudder Y degrees and such. When my TP-32 is connected to my NMEA2000 network, the IS40 display has a page that among other things shows rudder position. How else would it know?

[lockie]

Originally Posted by wsmurdoch

The hall sensors appear to be counting shaft rotations. It would be a handy thing for the autopilot algorithm to know... run the motor clockwise X seconds to move the rudder Y degrees and such. When my TP-32 is connected to my NMEA2000 network, the IS40 display has a page that among other things shows rudder position. How else would it know?

I spoke to the Oz Simrad tech support contact and he confirmed that these sensors monitor shaft rotation to allowing de-energising of the motor when it stalls (ie at end of stroke).

As for monitoring actual shaft (ie rudder) position, there is no mention of this function in the user or service manuals, which suggests this is not the case.

Cheers, Graeme

[wsmurdoch]

The TP10, TP22, TP32 Users Guide says, “The rudder position is captured at the first time initiation of the Autopilot mode. The information is however lost if the unit is turned OFF. Before initiating the Autopilot mode after a power down, you should ensure that the rudder is centered!” From that I guessed that my TP32 counted CW/CCW from that point using the Hall sensors on the little PCB and their magnets on the pulley.

I know for a fact that the rudder position is accurately displayed on my IS40’s “Steering” display. Somehow, someway, my TP32 keeps up with where its pushrod is located and tells my IS40 display where the rudder is located. It is my guess that the TP-32 counts ball drive shaft rotations using the two Hall sensors and magnets that I have seen at the motor end of the ball drive when I had the case open. But, truthfully, I don’t know. It is just electronic magic to me.

My system consists of a TP32 (I actually own two of them, one is a spare. Both have software version 1.1.03.00), an NSS chartplotter, A GS25 GPS and compass unit, and a RS35 VHF with a HS35 remote all on a NMEA2000 loop. All that stuff comes along with four IS15 displays, water and wind instruments, and a Simrad RA772 radar on a NMEA0183 network that is connected to the NSS. Hanging on the NMEA0183 loop are a number of USB things – a computer, a SignaLink sound card on the Icom IC-M710, a GPS puck, and a few other devises with their USB/RS232 converters. As best I can figure, only the TP32 tillerpilot “knows” the rudder angle, so it must be the thing telling the IS40 display. I have no way of monitoring a NMEA2000 loop, so I don’t really know.

Where did you find the circuit diagrams for the TP32? I’d like to have a copy.

[RaymondR]

Originally Posted by wsmurdoch

The TP10, TP22, TP32 It is my guess that the TP-32 counts ball drive shaft rotations using the two Hall sensors and magnets that I have seen at the motor end of the ball drive when I had the case open. But, truthfully, I don’t know. It is just electronic magic to me.

Two sensors are needed so that it can count both up and down, could be either end position detection to shut down the motor or position sensing or they could provide both functions.

[lockie]

I closely observed my TP22 to see what happens when it strokes out. At the end of stroke the motor is de-energised after a second or so, then has another couple of short bursts before stopping altogether It then remains de-energised until it reversed in the opposite direction.

So in addition to monitoring rudder position, the TP22 it actively detects stall and protects against grinding away to (eventual) destruction of the cogged drive belt like my ST2000+ did.

Shame, Raymarine, shame!

Cheers, Graeme

[hpeer]

My St2000 didn't destroy the belt, it destroyed the thrust bearing supports. It is as driving input into a lab wind vane">Aries wind vane so negligible force required.

Maybe it was hitting the end of travel and grinding on?