###### tags: `modern system`

# Tripo

## Change Log
|ver.|Date|Description|Author|
|----|----|----|----|
|1.0.0|2020-02-06|The first release|Ruby|

## Category
[TOC]

---

## Introduction

## Related Services
- [Converto](https://hackmd.io/@Ye0fx7gRQ76VNKwJJyVYdA/SJofhmFM8)
- Alerto
- Vehicol
- Drivo

## Related Collections
- [vehicle_statuses](https://dbdiagram.io/d/5e3a227a9e76504e0ef10aa7)
- trip_histories
- trip_points

## Main Functions

### Maintain vehicle_statuses
- vehicle_statuses.tripType
- Trip
> Receive engine start
> Receive during trip (valid L1) and only when tyip type is pakring
- Parking
> Receive sleep start, keep_alive, tow end
- Tow
> Receive tow start
- Unexpected engine start
> Receive unexpected engine start
- Long idle end/start
> Receive trip restart update as long idle end , then pack vehicle_statuses, update as long idle start with new trip
- vehicle_statuses.summary
- tripTime
> Total duration of this trip is defined as
> $\sum_{i=0}^n (reportTime_i - reportTime_{i-1})$
- distance
> Total distance of this trip is defined as
> $d=(odometer_{i} - odometer_{0})$

- speedinDistance
> Total speed distance of this trip is defined as
> $\sum_{i=0}^navgVssSpeed_i{\Delta}t$

- gpsDistance
> Total gps distance of this trip is defined as
> $\sum_{i=0}^n
> 2r \cdot arcsin(
> \sqrt{
> sin^2(\frac{\alpha_i - \alpha_{i-1}}{2}) +
> cos(\alpha_{i-1})cos(\alpha_i)
> sin^2(\frac{\beta_i - \beta_{i-1}}{2})
> }
> ) \ ,$
> $where \ (i) \ r =radius \ of \ the \ sphere$
> $(ii) \ \alpha = latitude \ of \ point \ in \ radians$
> $(iii) \ \beta = longitude \ of \ point \ in \ radians$

- tripStartTime
> Timestamp when start a trip, e.g., engine_on, receive during_trip (valid L1) when current trip type is "Parking", tow_start, trip_restart
- tripEndTime
> Timestamp when end a trip, e.g., engine_off, tow_end, trip_restart
- odoMeterStart
> The first valid odometer
- odoMeterEnd
> Current valid odometer
- startLatitude
>
- startLongitude
>
- startAddress
>
-

### Trip Points Creating
Tripo creates the [trip points](https://docs.google.com/spreadsheets/d/1Zr9yzV_JxYHf3Yo3zJzW6VpScZVlthe1zxncnZK6IpI/edit?usp=sharing) while one of the following events happends:
1. Receive "engine_start" event
2. Receive "engine_off" event
3. Receive "tow_start" event
4. Receive "tow_end" event
5. Receive "trip_restart" event (end point for current trip, start point for new trip)
6. No new trip point created for more than 1 km
7. No new trip point created for more than 10 mins
8. Heading changes more than 45 degree
9. Event point (manual event created by Alerto)

### Trip History Packaging
#### Step-by-step process
1. Check the trip type, where the trip types include:
- Trip
- Receive engine start
- Receive during trip (valid L1) and only when tyip type is pakring
- Parking
- Receive sleep start, keep_alive, tow end
- Tow
- Receive tow start
- Unexpected engine start
- Receive unexpected engine start
- Long idle end
- Receive trip restart
- Long idle start
- Receive trip restart
2. Pack the `vehicle_statuses` into `trip_histories`, if the trip type changes.
3. Create a document in `trip_histories` with the value in `vehicle_statuses`, where the [schama](https://docs.google.com/spreadsheets/d/1Zr9yzV_JxYHf3Yo3zJzW6VpScZVlthe1zxncnZK6IpI/edit?usp=sharing) of `vehicle_statuses` and `trip_histories` are totally the same.

### Message Forwarding

#### [trip_end event](https://hackmd.io/lAoHZ1KmQm6YHg_x6Os_PA)
###### Step-by-step process
1. Receives the ["sleep_start" event](https://hackmd.io/b3XKz_hYQou7S3Depah19Q) sent from *Converto*.
2. Pack `vehicle_statuses` into `trip_histories`
3. Sends the "trip_end" event to *Vehicol*, and *Drivo* via SQS queue, `{AWS_URL}/tripo_vehicol.fifo` and `{AWS_URL}/tripo_drivo.fifo`.

#### [sleep_end event](https://hackmd.io/lAoHZ1KmQm6YHg_x6Os_PA)
###### Step-by-step process
1. Receives the ["engine_start" event](https://hackmd.io/b3XKz_hYQou7S3Depah19Q) sent from *Converto*.
2. Sends the "sleep_end" event to *Devicio* via SQS queue, `{AWS_URL}/tripo_devicio.fifo`.