Thermal-Headroom Routing for Efficient Robot Perception in Extreme Heat
Organizations: Massachusetts Institute of Technology, Cambridge, MA, USA · Hopewell Valley Central High School, Pennington, NJ, USA · Paradise Valley High School, Phoenix, AZ, USA
Abstract
Adaptive robot perception systems must balance detector accuracy, inference latency, and energy consumption, particularly when high ambient temperatures cause processors to thermally throttle. We propose Thermal-Headroom Routing (THR), a lightweight model-selection policy that forecasts processor temperature using a closed-form RC thermal model and excludes detector configurations predicted to cross a throttling threshold. We evaluate THR with four YOLO11 configurations across seven real-world perception traces, eight ambient temperatures, and 20 randomized seeds, comparing it with latency-aware routing, fixed-threshold thermostats, duty caps, and a matched-compute-budget control. At ambient temperatures of 45-55 degrees C and a tight inference deadline, THR eliminates throttling in simulation, reduces deadline misses by 3.9-7.5 percentage points, and reduces energy per on-time frame by approximately 12-13% relative to a latency-belief router. A separate experiment using deadline-paced, nonoverlapping frame execution yields miss-rate reductions of 6.2-9.5 percentage points. A tuned thermostat or duty cap can match THR at a fixed operating point; predictive routing is most useful when ambient conditions or calibrated thermal parameters differ from those used to tune static policies. Measurements on an Apple M5 support the single-node heating approximation but do not validate hardware throttling. The results characterize the conditions under which thermal forecasting improves the efficiency and timeliness of resource-constrained robot perception.
Figures & tables
| (frame) | 0.1 s | / | 5 / 25 W |
| 30 s | / | 90 / 85 °C | |
| 2.0 °C/W | throttled power |
| Policy | Miss | Thr. | Blackout | Acc. | ||
|---|---|---|---|---|---|---|
| Ambient 45 °C | ||||||
| Static C1 | 60.3 | 20.3 | 12.5 | 23.0 | 5.79 | 1.000 |
| Static C4 | 0.0 | 0.0 | 0.0 | 5.6 | 0.56 | 0.695 |
| Reactive | 44.2 | 12.4 | 0.9 | 22.6 | 4.06 | 0.975 |
| Belief | 44.3 | 12.2 | 0.9 | 22.6 | 4.07 | 0.975 |
| Thermostat | 41.2 | 0.0 | 0.9 | 22.2 | 3.79 | 0.958 |
| Ambient 45 °C | Ambient 55 °C | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Trace | Blackout C1 | Thr. Belief | Thr. THR | THR | THR Tst | THR MB | Blackout C1 | Thr. Belief | Thr. THR | THR | THR Tst | THR MB | |
| Off-road (clean) | 12.5 | 13 | 0 | +4.9 ∗ | +1.6 ∗ | +0.2 | 90.7 | 38 | 0 | +7.2 ∗ | +3.9 ∗ | -0.1 | |
| Off-road seg. | 12.5 | 12 | 0 | +4.8 ∗ | +1.6 ∗ | -0.2 | 90.7 | 37 | 0 | +6.8 ∗ | +3.8 ∗ | -0.3 | |
| Rain | 12.5 | 13 | 0 | +4.4 ∗ | +1.9 ∗ | -0.1 | 90.8 | 36 | 0 | +7.1 ∗ | +3.7 ∗ | -0.3 | |
| Snow | 12.5 | 12 | 0 | +5.4 ∗ | +1.7 ∗ | +0.1 | 90.7 | 38 | 0 | +7.2 ∗ | +4.1 ∗ | -0.1 | |
| Fog | 12.4 | 11 | 0 | +4.8 ∗ | +1.9 ∗ | +0.0 | 90.7 | 34 | 0 | +7.5 ∗ | +3.8 ∗ | +0.0 | |
| Cap tuned at 45 °C | THR | |||||
|---|---|---|---|---|---|---|
| Ambient | Thr. | Miss | Acc. | Thr. | Miss | Acc. |
| 35 °C | 0.0 | 39.5 | 0.946 | 0.0 | 49.9 | 1.000 |
| 40 °C | 0.0 | 39.5 | 0.946 | 0.0 | 46.5 | 0.982 |
| 45 °C | 0.0 | 39.5 | 0.946 | 0.0 | 39.6 | 0.950 |
| 50 °C | 15.6 | 36.9 | 0.930 | 0.0 | 32.3 | 0.914 |
| 55 °C | 31.0 | 31.2 | 0.902 | 0.0 | 25.1 | 0.883 |
| Ambient 45 °C | Ambient 55 °C | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| True chip | THR | Sig. | Belief | Tst. | THR | THR | Sig. | Belief | Tst. | THR | |
| +0.0 to +0.0 | 0/7 | 0.0 | 0.0 | 0.0 | +4.7 to +6.1 | 7/7 | 17.0 | 0.0 | 0.0 | ||
| +6.7 to +7.9 | 7/7 | 28.4 | 0.0 | 0.0 | +8.2 to +12.1 | 7/7 | 51.8 | 29.0 | 0.0 | ||
| +7.9 to +9.6 | 7/7 | 15.8 | 0.0 | 0.0 | +11.0 to +14.7 | 7/7 | 42.3 | 2.7 | 0.0 | ||
| +3.7 to +4.4 | 7/7 | 0.0 | 0.0 | 0.0 | +4.8 to +5.6 | 7/7 | 25.5 | 0.0 | 0.0 | ||
| throttle power | +3.4 to +5.3 | 7/7 | 12.8 | 0.0 | 0.0 | +4.8 to +6.7 | 7/7 | 41.0 | 0.0 | 0.0 | |
| Thr. (%) | THR vs | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Amb. | B | Tst | Cap | THR | (pp) | B | Tst | MB | Cap |
| 35 °C | 0.0 | 0.0 | 0.0 | 0.0 | +0.0 to +0.1 | 0/0 | 0/7 | 0/0 | 0/7 |
| 45 °C | 15.5 | 0.0 | 0.0 | 0.0 | +6.2 to +7.8 | 7/0 | 7/0 | 0/0 | 0/0 |
| 50 °C | 27.6 | 0.0 | 23.0 | 0.0 | +8.2 to +9.5 | 7/0 | 7/0 | 0/0 | 7/0 |
| 55 °C | 40.3 | 1.5 | 37.4 | 0.0 | +8.0 to +9.1 | 7/0 | 7/0 | 0/0 | 7/0 |
| Miss (%) | Throttled (%) | U | THR vs B | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Amb. | B | Tst | THR | B | Tst | THR | B | Tst | THR | miss | U | |
| 1.0 | 35 °C | 49.9 | 49.9 | 49.9 | 0.0 | 0.0 | 0.0 | 0.501 | 0.501 | 0.501 | 0/0 | 0/0 |
| 45 °C | 44.3 | 41.2 | 39.6 | 12.2 | 0.0 | 0.0 | 0.532 | 0.546 | 0.554 | 7/0 | 5/0 | |
| 55 °C | 32.3 | 29.0 | 25.1 | 36.3 | 0.0 | 0.0 | 0.607 | 0.610 | 0.632 | 7/0 | 6/0 | |
| 1.25 | 35 °C | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 1.000 | 1.000 | 1.000 | 0/0 | 0/0 |
| 45 °C | 0.5 | 0.0 | 0.0 | 12.2 | 0.0 | 0.0 | 0.970 | 0.958 | 0.950 | 7/0 | 1/6 | |
| 25 °C | 45 °C | 55 °C | ||||
|---|---|---|---|---|---|---|
| Trace | J | J+T | J | J+T | J | J+T |
| Off-road (clean) | +0.0 | +0.0 | +0.0 | +6.0 ∗ | +0.0 | +7.9 ∗ |
| Off-road seg. | +12.7 ∗ | +12.7 ∗ | +12.2 ∗ | +13.1 ∗ | +9.0 ∗ | +13.3 ∗ |
| Rain | +9.7 ∗ | +9.7 ∗ | +9.5 ∗ | +9.7 ∗ | +5.8 ∗ | +10.1 ∗ |
| Snow | +5.3 ∗ | +5.3 ∗ | +3.5 ∗ | +7.0 ∗ | +1.6 ∗ | +8.8 ∗ |
| Fog | +12.5 ∗ | +12.5 ∗ | +8.8 ∗ | +9.1 ∗ | +3.4 ∗ | +9.2 ∗ |
| THR’s model | miss (pp) | Sig. | Acc. | Max thr. (%) |
|---|---|---|---|---|
| true model | +3.9 to +5.4 | 7/7 | 0.917 to 0.994 | 0.0 |
| +0.8 to +1.8 | 7/7 | 0.943 to 0.996 | 0.0 | |
| +7.1 to +9.0 | 7/7 | 0.888 to 0.993 | 0.0 | |
| +5.6 to +7.6 | 7/7 | 0.899 to 0.994 | 0.0 | |
| +3.2 to +4.4 | 7/7 | 0.925 to 0.995 | 0.0 |
| Burst share (%) | Max run | ||||
|---|---|---|---|---|---|
| Trace | Belief | Joint | (pp) | Belief | Joint |
| Off-road (clean) | 18.9 | 18.9 | +0.0 | 7.6 | 7.6 |
| Off-road seg. | 17.4 | 14.7 | +2.8 ∗ | 8.4 | 7.3 |
| Rain | 14.3 | 13.7 | +0.6 ∗ | 6.7 | 6.7 |
| Snow | 20.0 | 17.4 | +2.6 ∗ | 7.6 | 7.3 |
| Fog | 21.9 | 16.3 | +5.6 ∗ | 7.1 | 6.8 |
| Cfg | Lat. | First | Last | RMSE | ||||
|---|---|---|---|---|---|---|---|---|
| C1 | 189 | 187 | 186 | 14.6 | 20 | 41.1 | 2.81 | 0.99 |
| C2 | 55 | 55 | 55 | 13.8 | 19 | 38.9 | 2.82 | 0.80 |
| C4 | 7 | 7 | 7 | 7.7 | 45 | 25.7 | 3.33 | 0.88 |