| 摘要 |
In exemplary implementations of this invention, a basketball net or flat net measures the translational kinetic energy of a ball that passes through an aperture in the net or impacts the net. The net includes one or more electrically conductive cords, which have a resistance that varies depending on the degree to which the cord is stretched. From sensor measurements, a processor determines: (a) instantaneous rate of change of resistance, and (b) duration of a time period that begins when resistance exceeds a baseline (with hysteresis). In the case of a basketball net, a processor may calculate the translational kinetic energy of the ball as equal to a sum of two terms. The first term is inversely proportional to the square of the duration; the second is proportional to the square of the integral of the instantaneous rate of change of resistance over the time period. |
| 主权项 |
1. Apparatus comprising in combination:
(a) a flat net that includes N elongated components oriented in along a first direction and M elongated components oriented along a second direction; (b) at least one sensor; and (c) at least one processor;wherein
(i) each of the N+M components, respectively, comprises a material that has an electrical resistance that varies depending on the extent to which the material is stretched, (ii) the at least one sensor is configured to take measurements of changes in electrical resistance of each of the N+M components, respectively, (iii) the at least one processor is configured
(A) to calculate duration of a time period, which period starts when resistance exceeds a baseline plus a first amount and ends when resistance is less than the baseline minus a second amount,(B) to identify a particular component that exhibits maximum resistance out of the M components, or out of the N components, or out of the N+M components, during the time period,(C) to perform a computation to calculate, based at least in part on the measurements, a calculated value indicative of the translational kinetic energy of a ball that strikes the net, and(D) to output signals to cause an output device to render the calculated value in a human-readable form, (iv) the calculated value is in a range, which range is the range of values that may be outputted by the computation, and which range includes more than two values, and (v) measurements of resistance for the particular component taken during the time period are either (1) the sole measurements of resistance taken during the time period that are inputted into the computation, or (2) are weighted more heavily in the computation than measurements of resistance of other components taken during the time period. |
