Anticipative electric mower and method of piloting such a mower

• US 10,617,058 B2
• Filed: 12/06/2016
• Issued: 04/14/2020
• Est. Priority Date: 12/23/2015
• Status: Active Grant

• Current Assignee: PELLENC SA
• Original Assignee: PELLENC SA
• Inventors: Pellenc, Roger
• Primary Examiner(s): Pezzuto, Robert E
• Application Number:
  US15/767,324
• Publication Number:
  US 20180303026A1
• Time in Patent Office: 1,225 Days
• Field of Search: 56 102 A, 56 102 R, 56202, 56229, 700250, 700258, 700245, 700284, 700259, 701 23, 701 25, 701 50
• CPC Class Codes: A01D 2101/00 Lawn-mowers
• CPC Class Codes: A01D 34/006 Control or measuring arrangements
• CPC Class Codes: A01D 34/008 for automated or remotely controlled operation
• CPC Class Codes: A01D 34/58 electric
• CPC Class Codes: A01D 34/78 electric

Abstract

An electric mower of the battery-operated type has at least one cutting blade, an electric motor for driving the cutting blade, and an electronic piloting unit for the electric motor. At least one optical sensor is deposited upstream of the cutting blade. The optical sensor is configured to deliver; as the mower advances, at least one predictive signal of a quantity of plants to be cut. The electronic piloting unit is configured to establish an optimum rotation speed of the drive motor of the cutting blade, of said predictive signal of the optical sensor, and of a speed of advance of the mower. The method and apparatus are applicable at least to walk-behind mowers.

Claims

1. Electric battery-operated mower comprising:

at least one cutting blade;

an electric motor for driving the cutting blade;

an electronic piloting unit of the electric motor;

at least one optical sensor located upstream of the cutting blade, characterized in that

the optical sensor is oriented towards the ground with an inclination in the forward direction of the mower, and configured to deliver, as the mower moves forwards, at least one predictive signal usable for determining, after processing, at least one of;

height of plants to be cut, density of plants to be cut, and a combination of height and density of plants to be cut;

the electronic piloting unit is configured to establish an optimal rotation speed of the cutting blade drive motor, the optimal rotation speed being established on the basis of said predictive signal of the optical sensor, and of a forward speed of the mower chosen between a standard forward speed, a desired forward speed, and an effective forward speed.

2. Mower according to claim 1, in which the optical sensor presents sensitivity within a range of luminous wave lengths between 400 and 1200 nm.

3. Mower according to claim 1, including a light source for a measurement zone of the optical sensor located in front of the cutting blade.

4. Mower according to claim 3, in which the light source is integrated into the optical sensor.

5. Mower according to claim 4, in which the light source is pulsed light source.

6. Mower according to claim 1, including furthermore a speed sensor to establish an effective forward speed signal of the mower and in which the piloting unit is connected to the speed sensor to establish the optimal rotation speed of the blade drive motor based of the predictive signal of the optical sensor and based on the signal of effective forward speed.

7. Mower according to claim 1, including an input interface of a desired forward speed, for the control of at least one electric motor for moving the mower forward, and in which the piloting unit is connected to the interface to establish the optimal rotation speed of the blade drive motor based on the predictive signal of the optical sensor and based on the desired forward speed.

8. Mower according to claim 1, in which the piloting unit is associated to a correspondence table with a plurality of reference rotation speeds of the drive motor, the piloting unit being configured to select the optimal rotation speed of the blade drive motor among a plurality of reference speeds of the correspondence table.

9. Mower according to claim 8 in which the piloting unit is configured to establish an acceleration or deceleration value, respectively, between a current optimal rotation speed of the blade drive motor and a new optimum rotation speed established during the forward movement of the mower.

10. Mower according to claim 8 in which the piloting unit is configured to establish the acceleration or deceleration value respectively, based on the forward speed of the mower.

11. Mower according to claim 1, including a signal processing card associated to the optical sensor, the signal processing card being configured to establish a contamination signal of the sensor.

12. Mower according to claim 11, including a plurality of optical sensors the signal processing card being configured to establish the predictive signal based on a measurement signal of each optical sensor.

13. Mower according to claim 1, in which the cutting blade is fitted along a cutting plane and in which the optical sensor presents a measurement axis inclined in a forward direction of the mower, with an angle of inclination relative to the cutting plane between 15 and 75°

.

14. Mower according to claim 1, including a cutting casing housing the cutting blade, and in which the optical sensor presents a measuring zone located at a distance from the cutter casing between 10 cm and 30 cm and measured parallel to the forward motion of the mower.

15. Mower according to claim 1, characterized in that it is a walk-behind mower.

16. Piloting method of a drive motor of at least one cutting blade of an electric battery-operated mower, including:

a predictive measurement upstream of the cutting blade, and during the forward movement of the mower, of at least one of a height of plants, a density of plants and a combination of a height and density of plants susceptible to reach the cutting blade;

the establishment of a forward speed of the mower;

the setting, as the mower moves forward, of an optimal rotation speed of the cutting blade drive motor, the optimal rotation speed being established on the basis of said predictive measurement, and on the basis of the forward speed of the mower;

the electric supply for the drive motor with sufficient energy to cause rotation of the drive motor of the cutting blade at the optimal rotation speed.

17. Method according to claim 16 in which the setting of the optimal rotation speed of the blade drive motor occurs periodically.

18. Method according to claim 16, including a temporary and automatic raise of the cutting blade, in case of setting an optimal rotation speed exceeding the capacity of either the electric motor or the battery supplying the electric motor.

19. Method of claim 16, including the emission of a warning signal in case of setting an optimal rotation speed exceeding the capacity of either the electric motor or the battery supplying the electric motor.