MOWING CONTROL METHOD FOR INTELLIGENT LAWN MOWER

Abstract

The present invention discloses a method comprising: A. acquiring the current I0 and I, and setting It1, It2, IR, Vmin, and Vmax. B. acquiring the speed V, and setting the speed VL and VH; C. a mowing motor runs in a low-speed mode, and a self-propelled motor runs at the speed VH; D. when encountering grassy areas, if I0<I<It1, keeping unchanged; if I≥It1 and lasting for T1, skipping to E; if I=IR, skipping to G; E. the mowing motor switches to the high-speed mode; F. the mowing motor switches to the low-speed mode, V is switched to VH; G the mowing motor switches to the high-speed mode, V is adjusted to VL; H. the mowing motor stops, the self-propelled motors stop, then retreat and work along the original path, after attempting for M times, if the self-propelled motors stop again, bypassing and skipping to C to continue working.

Claims

1. A mowing control method for an intelligent lawn mower, said intelligent lawn mower comprises a left self-propelled motor (6), a left self-propelled motor control unit (2), a right self-propelled motor (5), a right self-propelled motor control unit (4), a mowing motor (1), a mowing motor control unit (3), a main control unit (7), and a boundary sensor (8), said left self-propelled motor (6) is connected to said left self-propelled motor control unit (2), said right self-propelled motor (5) is connected to said right self-propelled motor control unit (4), said mowing motor (1) is connected to said mowing motor control unit (3), and said left self-propelled motor control unit (2), said right self-propelled motor control unit (4), said mowing motor control unit (3) and said boundary sensor (8) are respectively connected to said main control unit (7), wherein: said control method comprises the following steps: A. acquiring, by said mowing motor control unit (3), a current I0 when said mowing motor (1) drives a blade for no-load operation and a real-time working current I, and setting a current threshold value for said mowing motor (1) to switch from a low-speed mode to a high-speed mode as It1, a current threshold value for said mowing motor (1) to switch from the high-speed mode to the low-speed mode as It2, a current limit value of a mowing drive current as IR, a minimum operating threshold value for speed protection of said mowing motor (1) as Vmin, and a maximum operating speed of said mowing motor (1) as Vmax; B. acquiring, by said left self-propelled motor control unit (2) and said right self-propelled motor control unit (4) respectively, real-time speed V of said left self-propelled motor (6) and said right self-propelled motor (5) during operation, and setting the speed during low-speed operation as VL, and the speed during high-speed operation as VH; C. when working, said mowing motor (1) runs in the low-speed mode, and said left self-propelled motor (6) and said right self-propelled motor (5) run at the speed VH; D. when encountering grassy areas, if the real-time working current I of said mowing motor (1) is I0<I<It1, then keeping the current state; if the real-time working current I of said mowing motor (1) is I≥It1 and it lasts for a period of T1, then skipping to step E; if the real-time working current I of said mowing motor (1) equals to the current limit value IR, then skipping to step G; E. said mowing motor control unit (3) switches said mowing motor (1) to the high-speed mode, at the same time said mowing motor control unit (3) requests said main control unit (7), said main control unit (7) sends a deceleration command to said left self-propelled motor control unit (2) and said right self-propelled motor control unit (4), and said left self-propelled motor control unit (2) and said right self-propelled motor control unit (4), after receiving the deceleration command, reduce the real-time speed V of said left self-propelled motor (6) and said right self-propelled motor (5) respectively at the same time, so that the real-time speed V is dynamically adjusted between VL and VH; subsequently, if the real-time working current I of said mowing motor (1) is I<It2 and it lasts for a period of T2, then skipping to step F; if the real-time current I of said mowing motor (1) equals to the current limit value IR, then skipping to step G; F. said mowing motor control unit (3) controls said mowing motor (1) to switch to the low-speed mode, at the same time said mowing motor control unit (3) requests said main control unit (7), said main control unit (7) sends an acceleration command to said left self-propelled motor control unit (2) and said right self-propelled motor control unit (4), and said left self-propelled motor control unit (2) and said right self-propelled motor control unit (4), after receiving the acceleration command, switch the real-time speed V of said left self-propelled motor (6) and said right self-propelled motor (5) to VH respectively at the same time; subsequently, if the real-time working current I of said mowing motor (1) is I≥It1 and it lasts for a period of T1, then skipping to the step E; if the real-time working current I of said mowing motor (1) equals to the current limit value IR, then skipping to step G; G. said mowing motor control unit (3) controls said mowing motor (1) to switch to the high-speed mode, said mowing motor control unit (3) requests said main control unit (7), said main control unit (7) sends a deceleration command to said left self-propelled motor control unit (2) and said right self-propelled motor control unit (4), and said left self-propelled motor control unit (2) and said right self-propelled motor control unit (4), after receiving the deceleration command, adjust the speed of said left self-propelled motor (6) and said right self-propelled motor (5) to VL respectively; subsequently, if the real-time working current I of said mowing motor (1) is I<It2 and it lasts for a period of T2, then skipping to the step F; if the load on said mowing motor (1) is too high and causes overcurrent shutdown protection of said mowing motor (1) or the speed of said mowing motor (1) is <Vmin and it lasts for a period of T3, then skipping to step H; H. said mowing motor control unit (3) controls said mowing motor (1) to stop, at the same time said mowing motor control unit (3) intercommunicates with said main control unit (7), and said left self-propelled motor control unit (2) and said right self-propelled motor control unit (4) control said left self-propelled motor (6) and said right self-propelled motor (5) to stop respectively, then said left self-propelled motor (6) and said right self-propelled motor (5) retreat first and then continue to work along the original forward cutting path; after attempting for M times, if said left self-propelled motor (6) and said right self-propelled motor (5) stop again, it is determined that the area is a dense grass area, then bypassing the dense grass area and skipping to the step C to continue working.

2. The mowing control method for an intelligent lawn mower according to claim 1, wherein: in the step E, the real-time speed V is dynamically adjusted between VL and VH following an equation V=VH*(I0/I)*K, where K is an adjustment coefficient, 0≤K≤1.

3. The mowing control method for an intelligent lawn mower according to claim 1, wherein: in the step H, said left self-propelled motor (6) and said right self-propelled motor (5) retreat first and then continue to work along the original cutting path, for which the specific steps are: said left self-propelled motor (6) and said right self-propelled motor (5) retreat at the speed VH for X1*N1 turns, and then continue to work at the speed VL along the original cutting path, said X1 is the coefficient of motor rotation, 0.1≤X1≤1, 1≤N1≤3.

4. The mowing control method for an intelligent lawn mower according to claim 1, wherein: in the step H, the method for bypassing the dense grass area comprises the following steps: F1. said left self-propelled motor (6) and said right self-propelled motor (5) retreat first at the speed VH for X2*G*N2 turns and then stop, where 0.1≤X2≤1, 1≤N2≤3, 1≤G≤5; F2. starting from the stopping point, with the center of the circle located on the line defined by the boundary sensor (8) and the stopping point, detouring forward in a semicircle of radius R towards the interior of the boundary line, where 0.3≤R≤1.

5. The mowing control method for an intelligent lawn mower according to claim 1, wherein: in the step A, said It1=I0*P, 1.1≤P≤5, and in the step D, step F, and step G, 0.1 s≤T1≤5 s.

6. The mowing control method for an intelligent lawn mower according to claim 1, wherein: in the step A, said It2=It1*Y, 1.2≤Y≤3, and in the step E and step G, 1 s≤T2≤5 s.

7. The mowing control method for an intelligent lawn mower according to claim 1, wherein: in the step A, Vmin=Vmax*L, 0.15≤L≤0.65, and in the step 0.1 s≤T3≤3 s.

8. The mowing control method for an intelligent lawn mower according to claim 1, wherein: in the step H, 1≤M≤5.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] FIG. 1 is a structural schematic diagram of an intelligent lawn mower;

[0044] FIG. 2 is a diagram showing the module connection of the present invention;

[0045] FIG. 3 shows a structural schematic diagram when bypassing a dense grass area according to the present invention;

[0046] FIG. 4 is a flow chart of the present invention.

DETAILED DESCRIPTION

[0047] The present invention will be described in further detail below in conjunction with the accompanying drawings 1-4 and specific embodiments, but they are not intended to limit the present invention:

Embodiment 1

[0048] As shown in FIG. 1 to FIG. 4, a mowing control method for an intelligent lawn mower, said intelligent lawn mower comprises a left self-propelled motor 6, a left self-propelled motor control unit 2, a right self-propelled motor 5, a right self-propelled motor control unit 4, a mowing motor 1, a mowing motor control unit 3, a main control unit 7, and a boundary sensor 8, said left self-propelled motor 6 is connected to said left self-propelled motor control unit 2, said right self-propelled motor 5 is connected to said right self-propelled motor control unit 4, said mowing motor 1 is connected to said mowing motor control unit 3, and said left self-propelled motor control unit 2, said right self-propelled motor control unit 4, said mowing motor control unit 3 and said boundary sensor 8 are respectively connected to said main control unit 7, said control method comprises the following steps:

[0049] A. acquiring, by said mowing motor control unit 3, a current I0 when said mowing motor 1 drives a blade for no-load operation and a real-time working current I, and setting a current threshold value for said mowing motor 1 to switch from a low-speed mode to a high-speed mode as It1, a current threshold value for said mowing motor 1 to switch from the high-speed mode to the low-speed mode as It2, a current limit value of a mowing drive current as IR, a minimum operating threshold value for speed protection of said mowing motor 1 as Vmin, and a maximum operating speed of said mowing motor 1 as Vmax;

[0050] B. acquiring, by said left self-propelled motor control unit 2 and said right self-propelled motor control unit 4 respectively, real-time speed V of said left self-propelled motor 6 and said right self-propelled motor 5 during operation, and setting the speed during low-speed operation as VL, and the speed during high-speed operation as VH;

[0051] C. when working, said mowing motor 1 runs in the low-speed mode, and said left self-propelled motor 6 and said right self-propelled motor 5 run at the speed VH;

[0052] D. when encountering grassy areas, if the real-time working current I of said mowing motor 1 is I0<I<It1, then keeping the current state; if the real-time working current I of said mowing motor 1 is I>It1 and it lasts for a period of T1, then skipping to step E; if the real-time working current I of said mowing motor 1 equals to the current limit value IR, then skipping to step G;

[0053] E. said mowing motor control unit 3 switches said mowing motor 1 to the high-speed mode, at the same time said mowing motor control unit 3 requests said main control unit 7, said main control unit 7 sends a deceleration command to said left self-propelled motor control unit 2 and said right self-propelled motor control unit 4, and said left self-propelled motor control unit 2 and said right self-propelled motor control unit 4, after receiving the deceleration command, reduce the real-time speed V of said left self-propelled motor 6 and said right self-propelled motor 5 respectively at the same time, so that the real-time speed V is dynamically adjusted between VL and VH; subsequently, if the real-time working current I of said mowing motor 1 is I<It2 and it lasts for a period of T2, then skipping to step F; if the real-time current I of said mowing motor 1 equals to the current limit value IR, then skipping to step G;

[0054] F. said mowing motor control unit 3 controls said mowing motor 1 to switch to the low-speed mode, at the same time said mowing motor control unit 3 requests said main control unit 7, said main control unit 7 sends an acceleration command to said left self-propelled motor control unit 2 and said right self-propelled motor control unit 4, and said left self-propelled motor control unit 2 and said right self-propelled motor control unit 4, after receiving the acceleration command, switch the real-time speed V of said left self-propelled motor 6 and said right self-propelled motor 5 to VH respectively at the same time; subsequently, if the real-time working current I of said mowing motor 1 is I>It1 and it lasts for a period of T1, then skipping to the step E; if the real-time working current I of said mowing motor 1 equals to the current limit value IR, then skipping to step G;

[0055] G. said mowing motor control unit 3 controls said mowing motor 1 to switch to the high-speed mode, said mowing motor control unit 3 requests said main control unit 7, said main control unit 7 sends a deceleration command to said left self-propelled motor control unit 2 and said right self-propelled motor control unit 4, and said left self-propelled motor control unit 2 and said right self-propelled motor control unit 4, after receiving the deceleration command, adjust the speed of said left self-propelled motor 6 and said right self-propelled motor 5 to VL respectively; subsequently, if the real-time working current I of said mowing motor 1 is I<It2 and it lasts for a period of T2, then skipping to the step F; if the load on said mowing motor 1 is too high and causes overcurrent shutdown protection of said mowing motor 1 or the speed of said mowing motor 1 is <Vmin and it lasts for a period of T3, then skipping to step H;

[0056] H. said mowing motor control unit 3 controls said mowing motor 1 to stop, at the same time said mowing motor control unit 3 intercommunicates with said main control unit 7, and said left self-propelled motor control unit 2 and said right self-propelled motor control unit 4 control said left self-propelled motor 6 and said right self-propelled motor 5 to stop respectively, then said left self-propelled motor 6 and said right self-propelled motor 5 retreat first and then continue to work along the original forward cutting path; after attempting for M times, if said left self-propelled motor 6 and said right self-propelled motor 5 stop again, it is determined that the area is a dense grass area, then bypassing the dense grass area and skipping to the step C to continue working.

[0057] Preferably, in the step E, the real-time speed V is dynamically adjusted between VL and VH following an equation V=VH*(I0/I)*K, where K is an adjustment coefficient, 0<K<1.

[0058] Preferably, in the step H, said left self-propelled motor 6 and said right self-propelled motor 5 retreat first and then continue to work along the original cutting path, for which the specific steps are: said left self-propelled motor 6 and said right self-propelled motor 5 retreat at the speed VH for X1*N1 turns, and then continue to work at the speed VL along the original cutting path, said X1 is the coefficient of motor rotation, X1 is 0.1, N1 is 1.

[0059] Preferably, in the step H, the method for bypassing the dense grass area comprises the following steps:

[0060] F1. said left self-propelled motor 6 and said right self-propelled motor 5 retreat first at the speed VH for X2*G*N2 turns and then stop, where 0.1≤X2≤1, 1≤N2≤3, 1≤G≤5;

[0061] F2. starting from the stopping point, with the center of the circle located on the line defined by the boundary sensor 8 and the stopping point, detouring forward in a semicircle of radius R towards the interior of the boundary line, where 0.3≤R≤1.

[0062] Preferably, in the step A, said It1=I0*P, P is 1.1, and in the step D, step F, and step T1 is 0.1 s.

[0063] Preferably, in the step A, said It2=It1 *Y, Y is 1.2, and in the step E and step G, T2 is 1 s.

[0064] Preferably, in the step A, Vmin=Vmax*L, L is 0.15, and in the step T3 is 0.1 s.

[0065] Preferably, in the step H, M is 1.

Embodiment 2

[0066] As shown in FIG. 1 to FIG. 4, a mowing control method for an intelligent lawn mower, said intelligent lawn mower comprises a left self-propelled motor 6, a left self-propelled motor control unit 2, a right self-propelled motor 5, a right self-propelled motor control unit 4, a mowing motor 1, a mowing motor control unit 3, a main control unit 7, and a boundary sensor 8, said left self-propelled motor 6 is connected to said left self-propelled motor control unit 2, said right self-propelled motor 5 is connected to said right self-propelled motor control unit 4, said mowing motor 1 is connected to said mowing motor control unit 3, and said left self-propelled motor control unit 2, said right self-propelled motor control unit 4, said mowing motor control unit 3 and said boundary sensor 8 are respectively connected to said main control unit 7, said control method comprises the following steps:

[0067] A. acquiring, by said mowing motor control unit 3, a current I0 when said mowing motor 1 drives a blade for no-load operation and a real-time working current I, and setting a current threshold value for said mowing motor 1 to switch from a low-speed mode to a high-speed mode as It1, a current threshold value for said mowing motor 1 to switch from the high-speed mode to the low-speed mode as It2, a current limit value of a mowing drive current as IR, a minimum operating threshold value for speed protection of said mowing motor 1 as Vmin, and a maximum operating speed of said mowing motor 1 as Vmax;

[0068] B. acquiring, by said left self-propelled motor control unit 2 and said right self-propelled motor control unit 4 respectively, real-time speed V of said left self-propelled motor 6 and said right self-propelled motor 5 during operation, and setting the speed during low-speed operation as VL, and the speed during high-speed operation as VH;

[0069] C. when working, said mowing motor 1 runs in the low-speed mode, and said left self-propelled motor 6 and said right self-propelled motor 5 run at the speed VH;

[0070] D. when encountering grassy areas, if the real-time working current I of said mowing motor 1 is I0<I<It1, then keeping the current state; if the real-time working current I of said mowing motor 1 is I>It1 and it lasts for a period of T1, then skipping to step E; if the real-time working current I of said mowing motor 1 equals to the current limit value IR, then skipping to step G;

[0071] E. said mowing motor control unit 3 switches said mowing motor 1 to the high-speed mode, at the same time said mowing motor control unit 3 requests said main control unit 7, said main control unit 7 sends a deceleration command to said left self-propelled motor control unit 2 and said right self-propelled motor control unit 4, and said left self-propelled motor control unit 2 and said right self-propelled motor control unit 4, after receiving the deceleration command, reduce the real-time speed V of said left self-propelled motor 6 and said right self-propelled motor 5 respectively at the same time, so that the real-time speed V is dynamically adjusted between VL and VH; subsequently, if the real-time working current I of said mowing motor 1 is I<It2 and it lasts for a period of T2, then skipping to step F; if the real-time current I of said mowing motor 1 equals to the current limit value IR, then skipping to step G;

[0072] F. said mowing motor control unit 3 controls said mowing motor 1 to switch to the low-speed mode, at the same time said mowing motor control unit 3 requests said main control unit 7, said main control unit 7 sends an acceleration command to said left self-propelled motor control unit 2 and said right self-propelled motor control unit 4, and said left self-propelled motor control unit 2 and said right self-propelled motor control unit 4, after receiving the acceleration command, switch the real-time speed V of said left self-propelled motor 6 and said right self-propelled motor 5 to VH respectively at the same time; subsequently, if the real-time working current I of said mowing motor 1 is I≥It1 and it lasts for a period of T1, then skipping to the step E; if the real-time working current I of said mowing motor 1 equals to the current limit value IR, then skipping to step G;

[0073] G. said mowing motor control unit 3 controls said mowing motor 1 to switch to the high-speed mode, said mowing motor control unit 3 requests said main control unit 7, said main control unit 7 sends a deceleration command to said left self-propelled motor control unit 2 and said right self-propelled motor control unit 4, and said left self-propelled motor control unit 2 and said right self-propelled motor control unit 4, after receiving the deceleration command, adjust the speed of said left self-propelled motor 6 and said right self-propelled motor 5 to VL respectively; subsequently, if the real-time working current I of said mowing motor 1 is I<It2 and it lasts for a period of T2, then skipping to the step F; if the load on said mowing motor 1 is too high and causes overcurrent shutdown protection of said mowing motor 1 or the speed of said mowing motor 1 is <Vmin and it lasts for a period of T3, then skipping to step H;

[0074] H. said mowing motor control unit 3 controls said mowing motor 1 to stop, at the same time said mowing motor control unit 3 intercommunicates with said main control unit 7, and said left self-propelled motor control unit 2 and said right self-propelled motor control unit 4 control said left self-propelled motor 6 and said right self-propelled motor 5 to stop respectively, then said left self-propelled motor 6 and said right self-propelled motor 5 retreat first and then continue to work along the original forward cutting path; after attempting for M times, if said left self-propelled motor 6 and said right self-propelled motor 5 stop again, it is determined that the area is a dense grass area, then bypassing the dense grass area and skipping to the step C to continue working.

[0075] Preferably, in the step E, the real-time speed V is dynamically adjusted between VL and VH following an equation V=VH*(I0/I)*K, where K is an adjustment coefficient, 0≤K<1.

[0076] Preferably, in the step H, said left self-propelled motor 6 and said right self-propelled motor 5 retreat first and then continue to work along the original cutting path, for which the specific steps are: said left self-propelled motor 6 and said right self-propelled motor 5 retreat at the speed VH for X1*N1 turns, and then continue to work at the speed VL along the original cutting path, said X1 is the coefficient of motor rotation, X1 is 1, N1 is 3.

[0077] Preferably, in the step H, the method for bypassing the dense grass area comprises the following steps:

[0078] F1. said left self-propelled motor 6 and said right self-propelled motor 5 retreat first at the speed VH for X2*G*N2 turns and then stop, where 0.1<X2<1, 1<N2<3, 1<G<5;

[0079] F2. starting from the stopping point, with the center of the circle located on the line defined by the boundary sensor 8 and the stopping point, detouring forward in a semicircle of radius R towards the interior of the boundary line, where 0.3≤R≤1.

[0080] Preferably, in the step A, said It1=I0*P, P is 5, and in the step D, step F, and step T1 is 5 s.

[0081] Preferably, in the step A, said It2=It1 *Y, Y is 3, and in the step E and step G, T2 is 5 s.

[0082] Preferably, in the step A, Vmin=Vmax*L, L is 0.65, and in the step T3 is 3 s.

[0083] Preferably, in the step H, M is 5.

Embodiment 3

[0084] As shown in FIG. 1 to FIG. 4, a mowing control method for an intelligent lawn mower, said intelligent lawn mower comprises a left self-propelled motor 6, a left self-propelled motor control unit 2, a right self-propelled motor 5, a right self-propelled motor control unit 4, a mowing motor 1, a mowing motor control unit 3, a main control unit 7, and a boundary sensor 8, said left self-propelled motor 6 is connected to said left self-propelled motor control unit 2, said right self-propelled motor 5 is connected to said right self-propelled motor control unit 4, said mowing motor 1 is connected to said mowing motor control unit 3, and said left self-propelled motor control unit 2, said right self-propelled motor control unit 4, said mowing motor control unit 3 and said boundary sensor 8 are respectively connected to said main control unit 7, said control method comprises the following steps:

[0085] A. acquiring, by said mowing motor control unit 3, a current I0 when said mowing motor 1 drives a blade for no-load operation and a real-time working current I, and setting a current threshold value for said mowing motor 1 to switch from a low-speed mode to a high-speed mode as It1, a current threshold value for said mowing motor 1 to switch from the high-speed mode to the low-speed mode as It2, a current limit value of a mowing drive current as IR, a minimum operating threshold value for speed protection of said mowing motor 1 as Vmin, and a maximum operating speed of said mowing motor 1 as Vmax;

[0086] B. acquiring, by said left self-propelled motor control unit 2 and said right self-propelled motor control unit 4 respectively, real-time speed V of said left self-propelled motor 6 and said right self-propelled motor 5 during operation, and setting the speed during low-speed operation as VL, and the speed during high-speed operation as VH;

[0087] C. when working, said mowing motor 1 runs in the low-speed mode, and said left self-propelled motor 6 and said right self-propelled motor 5 run at the speed VH;

[0088] D. when encountering grassy areas, if the real-time working current I of said mowing motor 1 is I0<I<It1, then keeping the current state; if the real-time working current I of said mowing motor 1 is I>It1 and it lasts for a period of T1, then skipping to step E; if the real-time working current I of said mowing motor 1 equals to the current limit value IR, then skipping to step G;

[0089] E. said mowing motor control unit 3 switches said mowing motor 1 to the high-speed mode, at the same time said mowing motor control unit 3 requests said main control unit 7, said main control unit 7 sends a deceleration command to said left self-propelled motor control unit 2 and said right self-propelled motor control unit 4, and said left self-propelled motor control unit 2 and said right self-propelled motor control unit 4, after receiving the deceleration command, reduce the real-time speed V of said left self-propelled motor 6 and said right self-propelled motor 5 respectively at the same time, so that the real-time speed V is dynamically adjusted between VL and VH; subsequently, if the real-time working current I of said mowing motor 1 is I<It2 and it lasts for a period of T2, then skipping to step F; if the real-time current I of said mowing motor 1 equals to the current limit value IR, then skipping to step G;

[0090] F. said mowing motor control unit 3 controls said mowing motor 1 to switch to the low-speed mode, at the same time said mowing motor control unit 3 requests said main control unit 7, said main control unit 7 sends an acceleration command to said left self-propelled motor control unit 2 and said right self-propelled motor control unit 4, and said left self-propelled motor control unit 2 and said right self-propelled motor control unit 4, after receiving the acceleration command, switch the real-time speed V of said left self-propelled motor 6 and said right self-propelled motor 5 to VH respectively at the same time; subsequently, if the real-time working current I of said mowing motor 1 is I≥It1 and it lasts for a period of T1, then skipping to the step E; if the real-time working current I of said mowing motor 1 equals to the current limit value IR, then skipping to step G;

[0091] G. said mowing motor control unit 3 controls said mowing motor 1 to switch to the high-speed mode, said mowing motor control unit 3 requests said main control unit 7, said main control unit 7 sends a deceleration command to said left self-propelled motor control unit 2 and said right self-propelled motor control unit 4, and said left self-propelled motor control unit 2 and said right self-propelled motor control unit 4, after receiving the deceleration command, adjust the speed of said left self-propelled motor 6 and said right self-propelled motor 5 to VL respectively; subsequently, if the real-time working current I of said mowing motor 1 is I<It2 and it lasts for a period of T2, then skipping to the step F; if the load on said mowing motor 1 is too high and causes overcurrent shutdown protection of said mowing motor 1 or the speed of said mowing motor 1 is <Vmin and it lasts for a period of T3, then skipping to step H;

[0092] H. said mowing motor control unit 3 controls said mowing motor 1 to stop, at the same time said mowing motor control unit 3 intercommunicates with said main control unit 7, and said left self-propelled motor control unit 2 and said right self-propelled motor control unit 4 control said left self-propelled motor 6 and said right self-propelled motor 5 to stop respectively, then said left self-propelled motor 6 and said right self-propelled motor 5 retreat first and then continue to work along the original forward cutting path; after attempting for M times, if said left self-propelled motor 6 and said right self-propelled motor 5 stop again, it is determined that the area is a dense grass area, then bypassing the dense grass area and skipping to the step C to continue working.

[0093] Preferably, in the step E, the real-time speed V is dynamically adjusted between VL and VH following an equation V=VH*(I0/I)*K, where K is an adjustment coefficient, 0≤K≤1.

[0094] Preferably, in the step H, said left self-propelled motor 6 and said right self-propelled motor 5 retreat first and then continue to work along the original cutting path, for which the specific steps are: said left self-propelled motor 6 and said right self-propelled motor 5 retreat at the speed VH for X1*N1 turns, and then continue to work at the speed VL along the original cutting path, said X1 is the coefficient of motor rotation, X1 is 0.5, N1 is 2.

[0095] Preferably, in the step H, the method for bypassing the dense grass area comprises the following steps:

[0096] F1. said left self-propelled motor 6 and said right self-propelled motor 5 retreat first at the speed VH for X2*G*N2 turns and then stop, where 0.1≤X2≤1, 1≤N2≤3, 1≤G≤5;

[0097] F2. starting from the stopping point, with the center of the circle located on the line defined by the boundary sensor 8 and the stopping point, detouring forward in a semicircle of radius R towards the interior of the boundary line, where 0.3≤R≤1.

[0098] Preferably, in the step A, said It1=I0*P, P is 3, and in the step D, step F, and step T1 is 2.5 s.

[0099] Preferably, in the step A, said It2=It1*Y, Y is 2.1, and in the step E and step G, T2 is 3 s.

[0100] Preferably, in the step A, Vmin=Vmax*L, L is 0.4, and in the step T3 is 1.5 s.

[0101] Preferably, in the step H, M is 3.

[0102] In summary, the above are only preferred embodiments of the present invention, and all equivalent variations and modifications made in accordance with the scope of the patent application of the present invention shall be covered by the present invention.