drivecycle 0.1.0

Create drivecycles and energy consumption simulations for vehicles.

Drive Cycle

Drivecycle is a python package that simulates complex velocity-time profiles for vehicles while taking into account stop and intersection locations along with speed limits. Drivecycle also simulates battery state of charge given vehicle (i.e. mass, battery type/capacity, etc.) and route (i.e. elevation change) characteristics.

Read the documentation for more details: https://saadiqm.com/drivecycle

Examples

Plot Simple Tragectories

The trajectory function can be used to generate a trajectory given some contraints such as distance, acceleration and start/end/target velocities.

from drivecycle import route, trajectory, plots, graph

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 - 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 = route.sequential(edges, stops=stop, stop_at_node=True, step=0.1)

Velocity - 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 = graph.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 vehicle 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 vehicle 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: