drivecycle 0.1.0a0

Create drivecycles and energy consumption simulations for bus routes.

Drive Cycle

Drive Cycle is python library that can be used to simulate trajectories (i.e. drive cycles) for public transit buses which can then be used for tasks like energy consumption simluations.

Installation

Install the package in editable mode:

pip install -e ./

Import Module

from drivecycle import drivecycle, trajectory, utils, plots

Plot Simple Tragectories

The Trajectory class can be used to generate a trajectory given some contraints such as distance, acceleration and start/end/target velocities. This current release only models constant acceleration trajectories however other models may be added in future.

traj = trajectory.const_accel(vi=5, v_target=12, vf=8, di=0, df=150, step=0.1)

plots.plot_vt(traj, "plot_vt.png")

Velocity - Distance Plot

Velocity - Time Plot

Distance - Time Plot

Generate Drive Cycle

Trajectories are grouped together to form drive cycles of a given path. See sample drive cycle input path. The drivecycle function may include a stops parameter that constrains which nodes (i.e. street interseciton or bus stops) the vehicle must stop at and for how long.

# What nodes should we stop at and for how long (seconds)
stop={"bus_stop":30,"tertiary":10}

# Generate route drive cycle
route_drive_cycle = drivecycle.sequential(edges, stops=stop, stop_at_node=True, step=0.1)

Velocity - Distance Plot

Velocity - Time Plot

Distance - Time Plot

Sample Path Input

A path graph data structure is created using OpenStreetMap (OSM) taxonomy. intersection denotes the edge that intersects the end node and may be another OSM way or simply a bus stop. For example "intersection":["primary"] indicates a primary road intersecting the end node.

path = [
    {
        "way_id":1,
        "speed":20,
        "length":100,
        "intersection":["primary"]
    },
    {
        "way_id":2,
        "speed":20,
        "length":145,
        "intersection":["primary"]
    },
    {
        "speed":20,
        "length":100,
        "intersection":["bus_stop"]
    },
    {
        "way_id":3,
        "speed":50,
        "length":150,
        "intersection":["primary"]
    },
    {
        "way_id":4,
        "speed":50,
        "length":100,
        "intersection":["tertiary"]
    },
    {
        "way_id":5,
        "speed":20,
        "length":100,
        "intersection":["service","service"]
    }
]

Generate Path Graph

Drive Cycle include utils that can used to generate graphs usting networkx. These are helpful to simplify path graphs to reduce redundant nodes and edges that may cause trajectories to fail. It can also be used to embed stops in a given path graph.

stops=[100,367] #linearly referenced stop locations

route_graph = utils.Graph(edges)

route_graph.include_stops(stops)
route_graph.consolidate_intersections(["tertiary", "secondary", "bus_stop"])
route_graph.simplify_graph(["tertiary", "secondary", "bus_stop"])

route_graph.get_edges()

Generate Drivecycle using Valhalla Trace Attributes

Valhalla's map matching API can be used to match a bus route geometry to OSM way ids. This can help us determine both road speeds and intersection locations along a route. Using the map matching Trace Attributes action, we can get a list of OSM edges the bus route travels along:

[{'end_node': {'type': 'street_intersection',
   'elapsed_time': 0.698,
   'intersecting_edges': [{'road_class': 'service_other',
     'begin_heading': 204,
     'to_edge_name_consistency': False,
     'from_edge_name_consistency': False}]},
  'length': 0.007,
  'names': ['48 Avenue NW'],
  'speed': 35,
  'way_id': 463682703},
 {'end_node': {'type': 'street_intersection',
   'elapsed_time': 7.607,
   'intersecting_edges': [{'road_class': 'residential',
     'begin_heading': 131,
     'to_edge_name_consistency': False,
     'from_edge_name_consistency': False}]},
  'length': 0.067,
  'names': ['48 Avenue NW'],
  'speed': 35,
  'way_id': 463682703}
  .
  .
  .

Using the drivecycle apis listed above we can then generate a simulation drivecycle of the entire route: